As many of you know, the much-anticipated NextLevel Pulsar launched earlier this month. The Pulsar is a collaboration between Jonathan Gagné, astrophysicist, coffee nerd, and author of The Physics of Filter Coffee, and NextLevel, manufacturer of the LVL10, and now the Pulsar. When the first generation of such brewers hit the market, Jonathan dubbed them “no bypass” because, unlike most coffee drippers, these brewers do not offer the water a way to bypass the coffee bed. The Tricolate and LVL10 were the most prominent no-bypass brewers. After using those brewers for some time, Jonathan realized they could be improved by the addition of a valve to allow a the grounds to stay submerged throughout the bloom, and by changing a few other features, such as the shower screen. The result is a dripper that makes great coffee and even extractions incredibly easy to achieve.

By now the first customers should have received their Pulsars, so I’d like to offer some tips here. While there are myriad ways to use the Pulsar, I recommend this as a starting recipe and technique before trying variations.

What you’ll need:

• Any type of kettle (pouring spout type not important)

• Digital gram scale

• Delicious coffee

• Good quality water for coffee making

• NextLevel Pulsar and filters

 

Here’s a video of me making a Pulsar using this recipe

 

Recipe outline:

• 25g coffee, ground coarser than for hand pour, finer than batch brew

• Prewet with 75g boiling water

• Bloom 45-60 seconds

• Total brew time of 3:30-4:30

• 17:1 ratio of water: coffee (by weight)

Technique

• Grind 25g of coffee coarser than for pourover, finer than for batch brew

• Boil water.

• Set filter in base of Pulsar

• Wet filter in Pulsar base with hot water, with valve open

• Drain water

• Mount barrel firmly on base, with threaded side of barrel down

• Pour coffee in Pulsar

• Shake Pulsar to level grounds, or use a WDT tool to stir and level grounds

• Start timer

• With valve open, pour 75g water just off the boil

• Immediately close valve

• at 45-50 seconds, Pour enough water to make slurry height 1cm above the grounds

• Open valve

• Pour in several short bursts. Attempt to maintain a slurry height of 1cm — 2cm during the entire brewing process

• Swirl Pulsar gently, immediately after last pour

Notes and Pro Tips

I prefer water chemistry with approximately 100 ppm general hardness and 40 ppm alkalinity for most coffees

For the uber-geeks, an 800-micron PSD peak is about the right grind size for a 25-g dose

I recommend using no less than 20g; 25g—30g provides adequate bed depth to decrease risk of astringency

Use WWDT (Wet Weiss Distribution Technique) during the bloom to ensure even flow through the coffee bed

If total brew time is shorter than 3:30, grind finer

If total brew time is longer than 4:30, grind coarser

Short blooms seem to enhance clarity and aroma

Longer blooms seem to enhance body and texture

For an in-depth discussion of the Pulsar and more tips, please see Jonathan’s recent blog post

A while back, Kody reached out to me to discuss workplace injuries among baristi. He offered to write this guest post to hopefully help baristi avoid pain and injury. This post is strictly educational, and not medical advice. I am grateful to Kody for his generosity and his patience while waiting for me to publish this post.

-Scott

My name is Kody Johnson D.C. I am a Chiropractor board certified in electrodiagnostic medicine (used to diagnose nerve issues like carpal tunnel), and interestingly the only other work I have had is in the third-wave coffee industry. Having worked for both third-wave shops and roasters, the first decade of my professional career consisted of working around, using, and cleaning a number of different espresso machines and coffee roasters. As such, I am intimately familiar with the biomechanics, ergonomics, and research surrounding working in the coffee industry.  Today we are going to look at a practical approach to preventing pain in the workplace. Now, full disclosure, there isn’t a ton of research on ergonomics within the coffee industry; what is available will be referenced, but some information will be pulled from other industries. The information presented here is strictly educational. Specific health issues should be addressed with a healthcare professional. With that being said, lets dive in!

1. Stay Active 

Many problems that we face as baristas can be avoided by simply having an active lifestyle. No, being a barista does not count as being active. Yes, being a barista is a physically demanding job, but that is not a substitute for physical activity. Physical activity is a recommendation that has remained consistent for the prevention of low back pain among workers. Even a recommendation like avoiding repetitious bending at the waist is not a clear-cut solution for occupational back pain, but exercise has remained consistent. This is particularly important when roughly 1/3 baristas report back pain related to their work.

2. Avoid Manual Tamps if Possible

Manual tamping is fine for home use, however, consistently using a standard manual tamp, puts excess force on the forearm, shoulder, neck, and back. This excess force makes it a suboptimal candidate for shop use. Ideally, a lever-based tamper or automated tamper would be the tool of choice either as a stand-alone entity or as an attachment available on some commercial grinders. If a manual tamper is desired, a flat palm-based tamper would be preferred to the traditional “T” shaped tamp. I know that last statement can be controversial, as people love their tamp of choice. There was a study done that looked at the force distribution, hand posture, and trunk posture that found palm-based tampers were less stressful in every category observed. Biomechanically, this makes sense as well. Given how much forceful gripping the average barista does, using a palm-based tamp would give the finger flexors a break, while a traditional tamp would still require use of the finger flexors. Additionally, it is difficult to tamp with a traditional tamp without using the shoulder to lift the arm away from the body. This action (called abduction), is used so frequently with portafilter use, pouring milk into pitchers, steaming milk, pouring drinks,  and cleaning milk pitchers that giving the shoulder a break from this motion for a different motion puts less repetitive stress on the shoulder. 

3. Death to Death Grips

Many of the hand and wrist problems in the barista world can be predominantly linked to forceful grips and forceful exaggerated movements in the wrist. Both grip and excess movements have been linked to Carpal Tunnel and epicondylitis. At every point when using your portafilter, avoid using a death grip. Keep a loose grip on the portafilter at all times, even when securing the portafilter into the machine. The same logic applies to removing the puck from the portafilter. Keep a loose grip and let gravity do the work to remove the used puck. Forceful slamming gives unnecessary stress to your wrist, and over time can lead to pain. Improper tamping and portafilter use has been shown to directly influence pain in baristas.

4. Steam With Your Eyes Not Your Neck

Work related neck pain has been linked with consistent neck flexion, especially when combined with shoulder movements.  This presents a problem because steaming milk combines both shoulder movement and neck flexion. Likewise pouring drinks also uses similar motions, consistent neck flexion with associated shoulder movement.  In general, try to keep the arms tucked into the body when steaming and look down with your eyes not your neck. If possible, make sure the machine is high enough to avoid using excess bending of the neck to look down.

5. Take Care of Your Mind

Any talk about neck and low back pain always needs to include a section on stress management. Stress/mental health are frequently associated with low back pain and neck pain. This is particularly important for a field that has both customer service components and physical stress components. Talking with a therapist or your primary care physician about treatment options for depression/anxiety is always a great idea.

6. Dress for Function not Style

Lastly, constant standing has been linked with multiple health conditions including low-back pain and leg pain. Because baristas spend a majority, if not all of their day on their feet, priority should be given to shoes that provide comfort and support rather than style. Addition of cushioned mats to stand on has also shown to be helpful in a similar manner.

The coffee community is a caring and passionate community of people that pose unique healthcare challenges. It has been my pleasure to be in your midst over the course of my life. I hope you find this information helpful to you as a barista or as a shop manager in facilitating the health of your workers. This is by no means an exhaustive list, but I do hope that the above topics prove useful and hopefully I will be writing a part two here soon. 

Kody can be contacted at [email protected] or on Instagram @drdarthdarkseid

Get Prodigal Coffee

Serving coffee at Sweet Spot Kaffee in Munich

I recently spent two weeks with John and Bugs from Decent Espresso, doing demonstrations of the DE1 as well as my forthcoming Filter 3.0 basket, throughout the Netherlands, Germany, Switzerland, and Austria. We did sixteen demonstrations in twelve cities, and it was a blast. Our hosts were incredibly gracious and generous, and everyone who came to the events seemed to enjoy the vibe and the coffee as well as the insights about extraction we have gained from using the DE1. 

As always happens when I spend time with John, we honed many of our ideas about coffee extraction, and came up with new ideas to work on in the future. Below is a blog-post version of discussions we had at our demonstrations. No matter how experienced you are at making espresso, I trust you will find some interesting food for thought in this post. 

The history of espresso machines

In the early days of the Decent DE1 machine, John created various profiles to mimic every significant espresso profile from history. The profiles included versions of lever profiles, the E61 profile, and the flat nine-bar profile common today. John did this to demonstrate the versatility of the DE1 and to show that anything any other machine can do, the DE1 can do it as well. That is still the case, and the DE1 does many things no other machine can do (a few manufacturers make claims about flow and temperature profiling, but don’t provide the data needed to see the accuracy of the claims.) During our demos, John talked about the evolution of espresso-machine design, where it where it went wrong, and how today’s most popular design is not well matched with lightly roasted coffee. 

Early espresso machines had manual levers (the barista applied pressure using a lever) while other machines had spring-loaded levers to apply pressure more consistently, and with an arc (preinfusion followed by a pressure rise, peak, and gentle decrease) similar to the pressure curve of the allongé graph in the next section of this post . The spring-loaded lever machines were arguably the peak of Italian espresso-machine design in terms of optimizing coffee quality. Over the years, most manufacturers abandoned the spring-lever design in favor of pump-driven machines that apply a constant nine bars of pressure. Such machines require less barista time and effort, but yield coffee flavor and extraction levels inferior to that of spring-loaded levers. 

Allongé

At the beginning of every demo, I served two allongés, a style of very long espresso. I pulled allongé in part because it’s a delicious way to extract lightly roasted coffee, and in part because it yields a lot of coffee, making it easier to serve a large crowd. 

Back when I founded Café Myriade in Montreal in 2008, every cafe in the city was expected to serve allongé, and it was the second-most popular drink after filter coffee. Back then, baristi simply pressed the shot button multiple times, or hit the continuous button, to make a very long espresso, using their usual espresso blend, grinder, and grind setting. Of course, such shots were very bitter and astringent. We did things differently; I dedicated a grinder to allongé, used a coarser grind than for espresso, created a diligent puck-prep routine to decrease channeling, and served only fruity, lightly roasted, washed coffees. 

I served allongé because it was expected; what was unexpected was how much I liked it. With our light coffees, allongé enhanced the fruit acids and made some memorable shots. Visiting coffee pros were often shocked by how much they enjoyed a 110-ml espresso! Subsequent trends such as “coffee shots,” “turbo shots,” and “extractamundo dos” were all descendants of my allongé, and I’ll discuss later how and why they differ from allongé. 

When I told John about allongé eight years ago, he programmed it as as 4.5 ml/s flow profile on the DE1.  That meant the machine would apply whatever pressure was necessary to yield 4.5 ml/s. Although the allongé we had served at Myriade were quite good, they didn’t compare to the allongé we served this month on the Decent, since at Myriade we had a Kees Van Der Westen Mirage, an excellent machine, but it could not control flow. 

For the record, the allongé we made on tour used 15g of grounds to yield 73g of coffee in 25 seconds.  

Note that the constant flow caused the pressure to naturally rise, peak, and decline steadily.  Pressure rises as the puck compresses and drops as the viscosity of the slurry decreases (Thanks to Jonathan Gagné for the insight that it is decreasing viscosity, more so than puck erosion, that causes pressure to drop.)

Graph of textbook, flow-profile allongé;  green=pressure, blue=flow,  brown=shot weight

Fines and channels

The pressure curves of most allongé look like the one above. However, when I pulled a few allongé using an Ethiopian coffee roasted by DAK, something interesting happened: the pressure and the flow levels both stayed constant. Many Decent owners are aware that the curves of Ethiopians and decaffeinated coffees behave differently from other coffees; that is because Ethiopians usually generate more fines than any other origin, and decaffeinated coffee yields more fines than even Ethiopians do. Larger amounts of fines help maintain puck integrity for longer.

Allongé of Ethiopian coffee with flat pressure and flow curves

Turbo Shots, Extractamundo Dos

A few years ago, Chris Hendon, et al. published a paper proposing to optimize the consistency and flavor of espresso by pulling fast and short “turbo shots.” They didn’t explicitly say their findings were only for lightly roasted coffee, but whether they knew it or not, their system wouldn’t work as well with dark roasts. The study’s authors used 15g in a 20g basket to yield 40g, using flat-six-bar pressure, and an EK43 grinder set coarser than the standard espresso grind size. They claimed more consistency and better flavor by pulling such shots vs conventional slower, higher-pressure espresso shots. 

When I read the paper, I appreciated their efforts, but lamented that they didn’t use a Decent, because had they used one for a while, they would surely have framed the paper differently. They were discovering things John, some DE1 owners, and I had known for years: lighter roasts taste better at faster flow rates, the optimal grind size is not the one that yields the highest extraction, but is slightly coarser than that (in order to limit excessive puck compression/flow suppression, which promote channels), and shots from most large, flat-burr grinders such as the EK, should be pulled shorter, presumably because of lower fines production than most traditional espresso grinders, as a lack of fines causes the puck to lose integrity earlier in a shot.

I believe the choice of six-bar pressure was merely a hack to decrease the severity of channeling, whether the authors were aware of that or not. Had they had better puck prep and a proper, complete preinfusion, they would likely have had different results, and preferred slightly higher water:grounds ratios. More fines would have also nudged them toward higher ratios. 

When I made allongé in Montreal, I used 22g in a 20g basket to create a deeper bed to decrease the risk of astringency. Deeper espresso beds generally increase body, decrease clarity, and lower the risk of astringency. I also used a Robur, which has conical burrs and produces more fines than an EK. The extra fines allow pressure to persist longer, and decrease channeli

   

Water can be a confusing topic. For example, as I have mentioned in The Professional Barista’s Handbook and Everything But Espresso, “alkalinity” and “alkaline” mean different things. Machine manufacturers focus on avoiding scale, but are generally not aware of what water chemistry is best for flavor, or how to balance the concerns of avoiding scale vs optimizing flavor.  Further, the industry’s historical focus on overall TDS has led to a misguided belief that having a reasonable TDS level means water is optimal for coffee making. 

I’ll do my best here to simplify the discussion to help cafes, baristas and roasters make decisions about water quality.
The important points to discuss are:  

• Alkalinity is the single-most important factor in how water will affect coffee flavor. 

• One must get a laboratory water analysis to know what water-treatment system is appropriate for a cafe or roastery. Test, don’t guess. 

• Beyond flavor, it is important to ensure your water will not cause scale to precipitate in your coffee machines. This is especially important in high-volume settings such as coffee bars. Sometimes one needs to compromise and allow a little scale or sacrifice a little flavor quality to balance those two concerns. 

Some definitions

TDS: Total Dissolved Solids. This means exactly what it says: how much stuff is dissolved in the water. Industry recommendations have historically been to use water with TDS of 100-150, but by itself, TDS is a relatively unimportant number. 

Hardness / General Hardness/ Temporary Hardness/ GH: this is the type of hardness created by dissolved calcium, magnesium, and iron cations. GH may influence flavor and scaling risk, but there is little consensus on the optimal level or the ideal balance of Ca+ and Mg+.

pH/ Potential Hydrogen: a measure of acidity, from 1—14. Neutral is 7.0.  The pH scale is famously confusing because it is logarithmic. In other words, a pH of 2 is ten times more acidic than a pH of 3. Coffee, having a pH around 5, is not all that acidic, despite its reputation. For reference, lemon juice (pH of 2) is 1000 times more acidic, and stomach acid can be far more acidic than lemon juice. Water pH is not particularly important when considering water for coffee because the alkalinity level will have a far greater impact on final acidity in the cup. 

Alkaline: this simply means pH is above 7, or the water is “basic” and not acidic. 

Alkalinity/ Bicarbonate/ Buffer/ Carbonate Hardness/ KH: As you can see by these terms, whoever created water-chemistry nomenclature was a misanthrope. Alkalinity is a solution’s resistance to becoming more acidic upon the addition of an acid. Alkalinity is — by far — the single most important factor in how water chemistry will affect coffee flavor. Simply put, higher alkalinity makes coffee less acidic. Lower alkalinity makes coffee more acidic. These statements are true regardless of the water pH. 

My personal preference for lightly roasted, well-developed beans is an alkalinity level of 30—40ppm.  Your preferences may differ, and there may be times you intentionally choose unusual alkalinity levels to enhance or tone down acidity, depending on the bean and roast quality and degree. For example, you may choose low-alkalinity water to enhance the acidity of a flat-tasting coffee, etc.
Please note that water can have high alkalinity (buffer) but not be alkaline. As I wrote in the The Professional Barista’s Handbook (2008): 

A solution can be very alkaline but have low alkalinity, and vice versa. As an analogy, think of alkaline as the solution’s location on the political spectrum. Let’s say alkaline refers to being on the right, and acid refers to the left; alkaline denotes being conservative, acid denotes liberal. (No political commentary intended!) Alkalinity, on the other hand, is analogous to stubbornness, or resistance, to becoming more liberal. Of course, one can be at either end of the spectrum (acid or alkaline) and still be resistant (have high alkalinity) or amenable (low alkalinity) to becoming more liberal. 

Water for coffee at home

If you make coffee at home, there are a few convenient options: 

1. Search online for your city’s municipal water-quality report. It may help you know if your tap-water alkalinity level is high or low, or if your water contains contaminants you want to avoid, and may only be removed via reverse osmosis. Knowing your tap-water chemistry will help you make an informed decision about how to optimize it for coffee brewing.

2. Bottled water: I’ve never been somewhere in the world that didn’t offer at least one bottled-water option that was pretty good for coffee brewing. It’s worth reading labels and looking online to learn more about the bottled-water options in your area. If you can’t find a single bottled water with your preferred alkalinity level, consider blending distilled water with other bottled water to achieve your target alkalinity.

3. Buy demineralized or distilled water, and add dry salts or a product like Lotus Water Drops. This can be a great way to learn the effects of different water chemistry on coffee flavor, and help you dial in your preferences. Many grocery stores sell affordable reverse-osmosis water that you can buy and pour into large, reusable jugs.

4. If your tap water is naturally good for coffee, you may want to use a simple carbon filter such as a Brita pitcher or similar. If your water is hard and/or has very high alkalinity, you may want to try the Peak Water pitcher or a similar product.

Water for coffee in a commercial setting

If you survey machine manufacturers, they will rightly steer you toward water treatment that will protect your machines from scale (the precipitation of CaCO3). However, most machine providers or servicers are not aware of what water chemistry makes coffee taste best.

A simple way to estimate the scaling potential of water at various temperatures is to use an online Langelier Saturation Index calculator. I have mentioned the LSI in several of my books: 

For many years, I battled with my espresso-machine supplier because he insisted that i use a water softener to protect the machine. I argued that I did not need a softener, since my water would not produce scale in the machine, and that further, softening very hard water damages coffee flavor, so a softener is never the best solution. He finally relented when I showed him the LSI. 

In more recent years, the industry has avoided the risks of water softeners by favoring reverse-osmosis systems with blending valves. These systems remove approximately 90% of the dissolved solids from water by reverse osmosis, and offer the option of blending the RO water with carbon-filtered tap water.
Let me offer an example of how to use an RO system with blending valve.  Let’s say your tap water has:

80 TDS

60 GH

60 KH 

but you prefer alkalinity (KH) of 30. 

The RO water will have KH of 6 (we will assume it removes 90% of dissolved solids in the water).  The “blending water” that passed only through a carbon filter will have KH of 60. 

If you use 55% RO + 45% blending water, the result will be: 

.55*6 + .45*60 = 3.3 + 27 = 30.3 KH 

Please note that while RO systems are common in cafes, they are inappropriate in places with soft tap water. For example, a cafe in Manhattan may have 25 TDS and 15 KH. Removing any minerals from that water would be a mistake, and the cafe should only use a sediment filter + carbon filter to remove undesired tastes and odors. 

Test, don’t guess

I always ask my clients to get a water test from a laboratory before choosing a water system. I have my preferred labs, and I would personally pay the $100-$200 for a test rather than get a free test from a water-treatment company, partl

   

Why I chose IMF for Prodigal

I’ve been asked dozens of times why I chose IMF for Prodigal, and not Loring or Probat. To understand that, I’d like to explain how those machines differ and why I believe IMF makes the best roasting machines in the world. 

Drum roasters vs air roasters

Although IMF and Loring machines have drums, most of us call them “air roasters” because they transfer heat almost exclusively by convection with little-to-no conduction. Some air roasters, such as Sivetz and Neuhaus Neotec move the beans via a “fluidized bed” of hot air; other air roasters such as IMF and Loring use a drum to direct the bean movement, independent of airflow. 

Over the years, marketers have done a good job of muddying the facts about drum vs air roasting. Air roasting advocates have often claimed all drum roasts are “burnt” and only air roasting is “clean” and some drum roaster fans have claimed air roasts have “no body” or “uneven development.”

While such claims may have some merit when a machine is used improperly, I do not think they accurately represent the results a semi-skilled operator would achieve. 

A skilled roaster will find drum roasts offer a little more body, a bit less flavor clarity or delicacy, and less inner-bean development at a given outer-bean roast color. All of those differences are due to drum roasters transferring more heat via conduction. 

Air roasters, on average, make inner-bean development easier and are less likely to impart roasty flavors. The same trade-off that exists between flavor clarity and body exists in roasting; increasing one decreases the other. 

Air roasters allow faster roasting than drum roasters do, since air roasters can operate at extremely high inlet-air temperatures without concern of overheating the drum surface. The common notion that roasts should take “10-12 minutes” or the like is an artifact of most roasters using drums; let’s say you put a massive burner in a 12kg Probat and roasted 12kg in six minutes; the drum would get so hot that it would sear the beans, causing tipping, scorching, and likely inadequate inner-bean development at lighter roast levels. But it’s common to roast in 6-7 minutes in air roasters; hot air does not damage beans (for reference, in my ROEST, I use an inlet temperature as high as 700 fahrenheit during my 200-g batches with no cosmetic or flavor damage. 

One could argue that roast consistency is a little easier with an air roaster, though I think nearly equal consistency is achievable in most machines, provided they don’t have features or control systems that interfere with an effective between-batch protocol. 

Which type of roaster is better? 

I don’t believe there is a one-size-fits-all roaster design. If you prefer darker roasts and maximum body, you should probably use a drum roaster. At darker roast levels, inner-bean development won’t be much of a concern, and you probably won’t mind the lack of flavor delicacy. 
If you prefer light roasts and high flavor clarity, you’ll probably want to choose an air roaster. 

But, dear reader, please do not misinterpret what I’ve written here: nowhere have I said that you cannot develop light roasts well in a drum roaster or impart roasty flavors in an air roaster.  These are merely comparisons of their relative performance.

IMF vs Loring

Given that I prefer light roasts and delicate flavors, I was definitely going to buy an air roaster for Prodigal. The choice came down to IMF and Loring. 

Both machines use air-recirculation: instead of having a burner for the roasting process and an afterburner to clean the exhaust air, they have one burner held at afterburner-level temperatures to clean the exhaust air and provide hot air for roasting. Both designs are more fuel efficient than using a drum roaster with an afterburner. But the similarities end there. 

Airflow: There are effectively two different airflows in IMFs and Lorings, what I’ll call “air throughput” and “recirculated air.” Think of them like this: imagine you are filling a leaky bucket with water from a faucet. The water entering the bucket and draining from the bucket are the “throughput.” If you simultaneously stir the water, that is the recirculation. The “types” of airflow in the IMF and Loring intermingle but their levels are independent. 

Both machines recirculate air through their burners, and assuming one maintains the burner temperature high enough, the air is “cleaned” of smoke and pollution, to prevent the recirculation from tainting coffee flavor. 

The amount of throughput in Lorings is correlated with the gas setting, in order for its fuel injection system to maintain a constant air:fuel ratio. So, when using a gas setting of 80%, the throughput is roughly twice as high as when the gas is at 40% (I’m not sure if it’s exactly a 1:1 ratio, but it’s close). I do not like this system for two reasons: it prevents the Loring from lending itself to inlet-temperature profiling (see below), and it means the air throughput is very low when using low gas settings late in roasts. This, to me, is the reason why the IMF is better at both controlling roasts through first crack and executing dark roasts. 

The IMF exhaust fan and burner temperature are independently controlled. That means we can have whatever throughput level we want at anytime. It also allows one to use inlet-temperature profiling, which is the best way to control an air roaster. 

Incoming air in the IMF is a combination of hot air from the burner and air from the roasting room, blended dynamically by a fluttering “vortex” valve that produces the desired inlet temperature at all times. The level of air throughput is determined by the exhaust fan setting, which is set by the operator.

To me, the only benefit of Loring’s lower overall air throughput is it makes the fuel efficiency higher than that of the IMF. The IMF’s higher air throughput offers superior control of roast curves at all times, especially when most needed late in a roast. 

Airflow: advantage IMF

Fuel Efficiency: advantage Loring

Drum: The Loring’s drum is solid steel, while the IMF’s is perforated. While I don’t think that’s a big deal, I would always choose a perforated drum in order to decrease potential conductive heat transfer.  

Drum: advantage IMF 

Productivity: Both machines can roast full batches faster than a drum roaster. Some Loring machines seem more powerful relative to stated capacity than others (The 15kg seems especially underpowered.) But IMFs are more powerful than Lorings at any size, and one can roast full batches in less than 8:00 in IMF with no compromise in quality. 

Productivity: advantage IMF 

Control System: Loring offers three ways to control roasts: manually changing gas settings, using automated burner recipes, and “profile roasting.” Burner recipes are like manual control, but with valve settings preset by the operator, and executed by the machine (Cropster Gas & Replay, and Artisan software offer this same option for any machine that has a digital gas valve capable of receiving commands from the software.) In profile roasting, which I wrote about here, the Loring uses a PID to change the gas setting automatically, in an attempt to trace the bean-temperature curve of a reference roast. The system does not perfectly trace curves, because profile roasting gets confused during the first minute of a roast while the BT reading drops. After the turn, the system does a relatively good job of tracing curves, assuming the operator has programmed a curve achievable by the automation. I find the profiling system useful for very dark roasts, but a skilled operator can usually roast more consistently in manual mode than in profiling mode. 

The IMF control screen allows the operator to create a twelve-step recipe using bean-temperature set poi

Photo courtesy of Dear Coffee Buyer by Ryan Brown

Since starting Prodigal, I’ve been thinking a lot about sample roasting. Sample roasting is arguably more important to final product quality than production roasting is, so I have been remiss in not discussing sample roasting more in the past.

What is sample roasting?

Sample roasting involves roasting small quantities of coffee, usually as little as 50g up to 200g, but most commonly 100g, to test and choose which lots of green coffee to buy. Sample roasting is also sometimes used to “profile” a coffee before production roasting, but the utility of such “profiling” is dubious. The word profiling can mean various things, but here it refers to the practice of attempting to learn how to roast a new coffee on a small machine, with the intention of transferring that knowledge to a larger machine. Unfortunately, it is difficult to transfer more than general insights (how much relative power does a coffee require to roast, approximately how does it behave around first crack, what roast color tastes good, etc.) from a small machine to a larger one. Profiling in this way can give one a “ballpark idea” of how to approach a coffee, but cannot, with our current technology and understanding, tell one precisely how to roast a coffee in a larger machine. 

Types of sample roasters

Historically, most sample roasters were small drum roasters with open-faced drums, such as in the photo above. While such dinosaurs often churn out surprisingly delicious coffee, they make consistent, predictable results nearly impossible. For a deep dive into why these machines offer poor consistency, and how to modify them for better results, please see my post HERE

In recent years, a plethora of +/-500g drum roasters have hit the market that offer more controlled and consistent, if not always as delicious, sample roasts. Most such machines come from China, have similar features, and none stand out as particularly special. The positive aspects of these machines include fully modulating control over gas, drum RPM, and airflow, and easy connection to software such as Cropster or Artisan. However, some of these machines roast with too much conduction, most have slow bean probes in frankly stupid locations, and some have the reliability of an Edsel. If you don’t know what an Edsel is, consider yourself fortunate.

If you are going to buy one of these small drum roasters, I recommend getting one of the cheaper ones, because they are all similar, with nearly identical designs, and usually require the user to replace and move the BT probe, possibly the gas-pressure gauge, and often a few other small features. 

More recently, air roasters such as the Ikawa, Kaffelogic, and Roest have hit the market. The potential roast quality out of air roasters is generally superior to that of drum roasters, since air roasters transfer little to no heat by conduction, but instead use convection, which makes it easier to develop coffee and avoid roasty (not a real word) flavors. Until recently, I was frustrated by the control and repeatability offered by most of these machines, although all have the ability to produce delicious coffee at least some of the time.

What I use

Prior to 2022, my preferred sample roaster was a 500g drum roaster. Such machines offer good data quality down to 100g batches, and offer probably the most insight into how a coffee may behave in a production roaster. Roast quality was “pretty good” but consistent and predictable. I’d rather roast at a quality level of 8/10 consistently than have erratic, and occasionally better, sample roasts, because one needs consistency to give each green sample a fair trial. 

More recently, at Prodigal I began using the Roest. For full disclosure, I did not pay for the machine. You don’t have to trust me, but no amount of free stuff could make me use anything but the best possible machine at Prodigal, or could compel me to write a blog post about a product. I needed a great machine to get the most out of my coffee, and for years I’ve been begging manufacturers to build exactly what Roest has built. 

My relationship with Roest was rocky at first, as I had a disagreement with someone at the company about roasting data. Because we had such different perspectives, I invited some of the Roest folks as guests at my roasting seminar in Boston last year. They took notes, asked questions, shared their experience designing machines with the class, and — wonderfully — embraced the importance of an effective warmup and between-batch protocol. They were excited, because they recognized an effective BBP was not only necessary for good consistency (yes, even in an air roaster), but also essential for successful automation and replication. I was excited, because a manufacturer finally engaged and cared about the importance of a quality warmup and BBP :). Further discussions led to the addition of an inlet-temperature probe, because using an inlet-temperature recipe is the most effective way to manage an air roaster consistently (more on that in a future post). 

A roast using an inlet-temperature profile (please ignore the “yellowing” note)

Last year, Roest added the ability to create customized warmup and BBP profiles, and now the machine automatically triggers the BBP upon dropping a batch. I cannot say how happy that makes me as a roaster, and also the only person yelling about the importance of an effective BBP for years. The last piece of the puzzle happened this month, as Roest now offers the option to create inlet-temperature profiles based on bean-temperature set points instead of time. Such as system makes consistent, predictable, high-quality roasting possible in a way it had never been before. 

I’m grateful to Roest for the machine, but more grateful they care about details, consistency, and continual improvements. Choosing a sample roaster is finally a no-brainer for me.

NB: Readers may notice some similarities between the Roest and the Decent espresso machine. I’m fond of both machines for similar reasons: each is a seamless marriage of user-friendly, clever software and hardware, both companies listen to feedback and rapidly improve and update their software and hardware, and they offer unparalleled control and real-time information while roasting and making espresso, respectively. Most importantly, each offers better coffee, more consistently, than any other machine in its category.

View fullsize

Ahead of the launch of Prodigal, Mark and I cupped for a minimum of one hour each morning. Having such a routine allowed us to calibrate well after cupping more than 2000 samples together. Those sessions also taught us a lot, some of which I’d like to share here.
 
First, I want to credit Ryan Brown. Over the years, I learned a lot not just from cupping with Ryan, but from throwaway remarks he would make. To him, many of those remarks were the equivalent of cupping small talk. To me, they often held pearls of hard-earned wisdom. Ryan is rigorous in creating systems that prevent bias and help to confirm his findings about samples. A good green buyer cups each sample multiple times on multiple days and does everything possible to avoid bias.
 
Until launching Prodigal, most of my cupping was done through the eyes of a production roaster and cupping was mostly an exercise to evaluate roast quality. I focused on problems of baking, roast development, side effects of excessive conduction, and the like. I did not cup to intensely analyze the merits of one green lot vs another. But production-roast cupping improved my green-evaluation skills. 

Herein are what I consider some cupping best practices. 

Always cup blindly

This rule may seem obvious, but in my experience, few roasters follow this rule religiously. I get it: cupping blindly with others can be embarrassing and humbling. But cupping isn’t a competition. You can either protect yourself from looking bad, or you can learn from experience, but you can’t do both well at the same time. Suck it up, make mistakes, and don’t worry if you thought that wet-hulled Sumatra was a washed Kenya. It happens to everyone. 

As often as possible, consder “double blinding” a cupping by having someone else set up the cupping so the cuppers do not know what coffees are on the table. 

To make cupping as blind as possible, consider hiding visual differences in coffees; for example, if you have a variety of roast levels on the table, it helps to cup in bowls with black interiors, in order to not see the colors of the brews. Some training sessions even use sunglasses to decrease visual cues about samples. 

Please do not use the traditional practice of setting a sample tray of roasted coffee next to each cupping bowl. That makes it impossible to be appropriately blind when looking at the roasted beans of a sample. 

Always cup with others

Cupping with others is far more educational than cupping alone. Various people will perceive different flavors in coffees, and some people are better at perceiving certain defects than others are. Cupping with others is a great way to expand your tasting abilities. For example, Mark is better than I am at tasting certain underdeveloped flavors, while I am more likely than he is to detect fade in coffee samples. Cupping together helps us shore up our weaknesses. 

Try to cup with more experienced professionals whenever possible. 

This is a no-brainer. Cupping with more experienced pros is by far the best accelerant if you want to get better at tasting coffee. 

Always take notes during cupping

Please don’t try to memorize your impressions of 5–10 cupping bowls; it is always better to take notes to discuss results with others, for scoring coffees accurately, and for future reference. I don’t believe one needs an official score sheet to score samples accurately, but I do believe it takes months of calibration practice to score accurately and consistently. 

Wait until after everyone has done at least one round of slurping and note taking before discussing samples

I’ve been to many cuppings where people begin discussing the coffees as soon as they begin tasting. That is more fun than taking notes silently, but it also inhibits learning and increases the risk of bias. 

Be as rigorous as possible in cupping procedure

What I mean by this is: use a consistent grind setting (I usually grind at a setting 1-2 integers finer than a typical 20g pourover setting) and water chemistry, weigh grounds to 0.1g resolution, weigh water to within a few grams per bowl, grind, pour, and taste on a timer with a rigorous schedule, and consider cupping at a brisk but comfortable pace to ensure you are tasting all samples at similar temperatures. Ryan taught me to take just one or two slurps per sample and to focus hard on those slurps. That has helped me cup more quickly. Previously I was taking too many slurps per bowl, which was taking too much time, decreased my focus , and caused my palate to fatigue earlier. 

Take one or two slurps, jot down a couple of words in your notes, and move to the next bowl. It’s okay if you don’t perceive an encyclopedia of descriptors after just one or two slurps. 

When cupping to choose green, do your best to optimize cup quality

When cupping to decide what green lots to purchase, sample roasting and cupping should be done in a way that optimizes cup quality.  That will allow each green lot the shine and show its best features. 

When cupping for production roasting QC, consider sacrificing cup quality, if necessary, in order to detect roast defects more easily

Let me explain this idea… Personally, I use an identical procedure when cupping for green buying and cupping for production roast analysis. However, I’ve cupped with many companies whose coffees tasted better when using a coarser grind or lower water temperature during cupping. In those situations, grinding finer or brewing hotter likely highlighted roast defects. If your cuppings taste better at grind settings coarser than your typical pourover grind setting, then there is probably work to do to improve roast quality. But please do not change the grind setting or water temperature to improve the flavor of cupping bowls.

Always cup at least one sample from another roaster on every table for context

I find many roasters are biased in favor of their own coffees. I recommend roasters find the best coffees they can from competing roasters, and to always have at least one such sample on every cupping table for context. 

Test the effectiveness of your cupping system

Many roasters have told me something like “This coffee cupped sharp on day one out of the roaster, was super fruity on day two, the flavors were muted for a few days and then the coffee was cupped great again after one week.” While I don’t doubt that cupper’s experience, it is unlikely the coffee really got worse, better, worse, and better. It’s possible, of course, but it’s more likely the cupping system is to blame, or the coffee has an abundance of quakers or other dodgy beans that show up in some samples but not others. 

To test the reliability of your cupping system, try something like this: 

• Scatter three bowls of the same coffee among several other coffees on the cupping table. Note whether your tasting notes and scores were consistent for those three bowls. 

• Taste several bowls of the same coffee several days in a row, again scattered among other samples, to see whether your notes change day to day. 

With a little effort, you can taste the baseline reliability of your cupping system. If the three bowls in each of the trials above tasted and scored identically, your system is probably reliable. If the three bowls varied a lot in flavor

, it’s important to run the same test with a few other coffees to see whether the cupping system or the coffees themselves are inconsistent. 

In general, scattering multiple bowls of a particular sample throughout a cupping table and trying to identify them is an excellent exercise to hone your tasting ability. 

Re-cup your roasts several times over the few weeks after roasting

Once you have shored up the reliability of your cupping system, it is worth tasting various roast batches over several weeks after roasting to perceive how the coffee ages and evolves. You may find your coffees typically peak after a certain number of “resting” days or you may find your coffees peak within a day of roasting and decline from there. 

Regularly testing and monitoring the quality of your roasts as they age can help you optimize your customers’ experience. 

Cup more rigorously when purchasing green than when analyzing sample roasts

When cupping to select green for purchase, I consider it essential to cup multiple bowls of a candidate sample multiple times before choosing a green lot. Not only do I want several looks at a coffee in order to avoid defects that may appear i

Lessons from the first month

We received multiples more inquiries than we had coffee available. Some of that was due to us deciding some of our green, once arrived, was below our quality standards for Prodigal, and some was due to my poor forecasting skills. 

Roasting and filling orders and handling inquiries was quite a challenge, as we had expected a much slower start. To be frank, no part of the process ran as smoothly as I would have liked, but we intend to be far more prepared for our next roasting and fulfillment session. 

Before the launch we did not have a green moisture meter, color meter, or enough staff to double-check every order. We also didn’t have experience with how our roasts would evolve due to travel and resting. All of that is sorted now. 

The first day of roasts (Jan 4) cupped beautifully directly out of the roaster and the next morning. A week or two later, the coffees tasted “too developed” but not roasty. I issued a public apology and offered to make any dissatisfied customers whole. Three customers took us up on that offer. 

Working on a new machine in an environment I couldn’t control was challenging. Contrary to popular belief, roasting is about systems and controlling variables, not about sniffing beans in a trier or some sixth sense about what is happening to 50,000 beans inside a giant hunk of hot metal. Having sixty batches under our belts, learning when to roast (at night, in a sealed, climate-controlled space), and how our coffee would age with time, will all contribute to future improvements. 

The vast majority of feedback was wildly positive; we received many comments such as “the best coffee I’ve tasted in over six months,” “the juiciest roast I can remember,” etc. The majority of critical comments were something like “it was not roasty but it was more developed than I prefer.” As noted, those batches have been acknowledged, and I don’t expect many of those roasts or comments in the future, other than from the more extreme tasters out there. Doing the best one can is not the same as pleasing everyone. 

A couple of weeks ago we upgraded our sample roaster and began using the Roest. After a few days of a steep learning curve on the Roest, we’ve settled into a system using the new inlet-temperature recipe program and automated BBP.  We’ve been pleased with the overall results. I’ll write a post soon about our experience with the Roest. 

We sold coffee wholesale to three cafes with whom we had prearranged deals. With apologies to others who made wholesale inquiries, we did not have enough green to sell wholesale to any other cafes. We hope to change that soon, but it will depend on retail demand and green availability. Likewise, we hope to offer a subscription soon, but cannot do so until we are confident about having a steady stream of green that meets our quality threshold. 

Roast level vs quality of roast

Having consulted for well over a thousand roasters over the years, I have to remain relatively adaptable about roast level. It is not my job to tell my clients how light or dark to roast, it is to help them achieve their desired roast level in the highest-quality and most consistent way possible. I’ve literally never told a client “you have to roast darker (or lighter)” or “you have to roast to 20%DTR,” etc. What one writes in a book for mass consumption is necessarily different from what one prescribes to a roaster with a particular machine and unique goals. As a consultant, step one is to ask a client his or her goals. Step two is to help them achieve those goals. Everything must be customized for that client.

Like any coffee drinker, I have my personal preferences. I prefer light, juicy roasts of clean —usually washed —  coffee, and famously despise funk. I respect that others have different preferences. 

There is, however, a difference between roast level and quality of roast. 

I’ve noticed many people confuse the two. A roaster may roast darker than I like, but do a great job of optimizing that roast level. Likewise, another roaster may roast in the color range I prefer, but the coffee may be baked or underdeveloped. I do not judge roasts solely by the final color, I also judge them by how skillfully the roaster achieved that roast level. 

Roast level is a style choice. Roast quality is independent of roast level. I don’t see that distinction made often enough. 

What’s next

Prodigal will release four new coffees this week. I’m pleased to say the new release will include our first natural :0, our first blend (the components of which will remain a mystery until next week’s blog post), a new shipment of the lovely Betel Geisha, and our first coffee from Ecuador.

We always notify our Prodigal Mailing List subscribers a day before anyone else of our new releases. If you don’t want to miss out on the new offerings, please consider joining the mailing list. 

Thanks for your support

“Transparency,” like “sustainability,” is a word thrown around too often. Let’s face it, very little in modern society is truly sustainable. Likewise, transparency in business is always selective and limited. 

It is nice to know that a roaster paid $10/kg FOB or $5/KG at the “farm gate” but do we know what that really means to the producer? It’s always more complicated than it seems. We paid $19/lb ($41.80/kg) before shipping for our two Betel coffees, but we don’t know César’s input costs or the cost of living in his part of Colombia. I don’t know how he and his family are doing financially, but he produces lovely coffee and he seems happy. 

It’s easy to say “this is what we paid” but it’s difficult to know what the numbers mean. One USD of income is a very different thing in Cauca and Copenhagen. I can imagine economists arguing endlessly about how to compare the value of a dollar in each place.

Financial transparency is nice, but tricky to make sense of at times. 

At Prodigal, we hope to practice a different type of transparency more relevant to our customers: owning up to our virtues and mistakes. I’ve ordered coffee from hundreds of respected roasters over the years, and as every honest, experienced coffee professional knows, inconsistency is rampant in our industry. 

Sources of inconsistency in coffee

Green coffee quality can change radically from the cupping table at a mill, to a PSS (pre-ship sample) from an importer, to an arrival or spot sample offered in the country of the roaster. A small change in green temperature or ambient roastery temperature can be the difference between a deliciously developed and underdeveloped roast. Heck, even what was roasted the previous batch can dramatically impact the current batch, unless one has an appropriately slow, systematic BBP (between-batch protocol), and even then, there are times when a BBP has a difficult time compensating for extreme changes in batch-to-batch roast styles (eg switching from a dark roast to a light roast or changing batch sizes mid-session can cause a roaster fits.) Throw in problems with water chemistry, brewing technique, and grind quality, and it’s a wonder that we ever enjoy two consecutive cups of coffee. 

Prodigal: consistency, standards, and flops

When Mark and I launched Prodigal, we fretted over every detail that could affect quality, and we still came up short in some ways. For example, we cupped over 100 green samples, begged suppliers to be very selective in what they sent us, and we purchased only seven coffees.

All of the coffees we purchased cupped at 87.5+ as PSS. We score strictly, and if you see any green sellers or roasters claiming they are awash with 88+ coffees, please disregard them. Score inflation is real. We calibrate with COE judges and impartial Q Graders, not marketing scores. 

Upon arrival, a few coffees held up and matched their PSS quality, and a few declined by 0.25-0.75 points across numerous sample roasts. We made the difficult decision to not sell those coffees as “Prodigal” because we want to uphold a certain standard for our brand, even if it means we sell less coffee. All of the rejected coffees are still lovely, and i reckon almost any coffee pro would happily drink them. 

We are selling our good-but-rejected arrivals as green coffee to home roasters, as they are tasty, and a bargain relative to what home roasters can source through the usual channels.

Green buying is the most important and difficult job of a roasting company. Green coffee is alive and constantly changing. Precious, delicious green gets exposed to a variety of conditions between the mill and the roastery that can and will degrade quality. We missed by a little on three of our seven purchases. We will find transparent ways to unload our green that doesn’t make the cut.

Roasting

I separate third-wave roasters into three groups; note that companies I refer to here may offer more than one roast level or style. I am focusing on their “filter” roast offerings, and don’t mean to imply that they target only one goal or style for all of their offerings. They are merely illustrative examples using high-quality, familiar roasting companies. I have enjoyed coffee from all of these companies and roast styles at times.

“Nordic” style roasters favor cup clarity above all else. Examples of such roasters include Sey, La Cabra, and Tim Wendelboe (Tim crosses over into the “maximum juiciness” group frequently, in my opinion.) Fans of those companies are virtually allergic to “roast” flavors and most fans would probably choose to sacrifice some sweetness, body, and juiciness to achieve maximum clarity. One may often need to “rest” Nordic roasts for several weeks or months to decrease the perception of underdeveloped flavors.

“Maximum juiciness” roasters target a balance of acidity and sweetness, and are willing to sacrifice a bit of body or clarity to achieve their aims. Such companies include Regalia, Nomad, and Doubleshot.

“Fully developed” third-wave roasters focus on sweetness and juiciness, and sacrifice a some acidity and clarity to meet their goals. Examples of such roasters include Onyx, Go Get ‘Em Tiger, and Blue Bottle.

Each group has its fans and detractors. Some Nordic-style fans tend to call everything else “dark,” which is like a guy who is 6’5” calling everyone else short.

The common complaints about Nordic roasts, beyond their light, tea-like body, include flavors reminiscent of peanuts, vegetable broth, grass, and cellulose. Most Nordic roasters drift into that flavor territory periodically. To me, it is a fail; to others, it’s no big deal.  

“Maximum juiciness” roasts may be too low in clarity or acidity or body, depending on the coffee drinker. 

“Fully developed” roasters may stray into “roasty” territory on occasion, or suppress acidity enough to make some coffees taste a little dull. 

For the record, my personal preference is on the light end of maximum juiciness. But it is not always wise to attempt to target one’s ideal roast level, as discussed below. 

   

Welcome to my semi-annual Holiday Coffee-Gift Guide. I thought it would be nice to suggest a few coffee-related gifts for the coffee nerd in your life. I won’t tell if you buy yourself the gifts or ask me to send this blog post to a family member ;).  

These suggestions are completely biased: they are all products I enjoy, and some that I sell.

 

Barista Hustle Subscription

Forget overpriced, dumbed-down industry courses; the BH Unlimited Subscription is hands down the best all-around online coffee education money can buy. Coming from someone who offers coffee education for a living, I hope those words carry weight. Whether for you or for your café staff, BH is the best option. In 2023, BH Unlimited is going to get even better, as a certain blogger you follow will be contributing to the subscription’s roasting content.

Click HERE to sign up and get a 14-day free trial. 

Lagom P64 and P100

If you *really* like someone, get him or her a Lagom grinder. The Lagom P64 and P100 are the best single-dosing grinders on the market, in my opinion. The grinders are beautiful, have low retention, excellent burrs, adjustable RPM (an important, underrated feature), and the are well-aligned at the factory (Thank you, Option-O, for caring.)  In other words, Lagom offers everything you can ask for in a grinder. 

Photo @Juheegrapher

 

Spinware Ceramics

Crafted by my friend Martina in Golden, CO, Spinware Ceramics are clean, beautiful, functional, and durable. Martina’s work would make a great gift for anyone who drinks coffee or tea. 

From Spinware’s website:

“When you buy a handcrafted piece from a ceramic studio, you are buying more than an object. You are buying hours of experimentation and error. You are buying moments of frustration and happiness. You are buying a piece of heart, a piece of soul, and a piece of someone else's life.”