Comparative Cupping: Sample roasting on the MCR500, Ikawa Pro, and Stronghold S7

When you’re comparing coffees at a purchase cupping and your menu and your budget is on the line, it’s crucial to be able to taste that coffee and experience its full potential. 

When sample roasting, professionals follow a standardized protocol. They prepare samples that are roasted quickly and to a light roast level to highlight the presence of any green coffee defects. The coffee must rest for a short time and be evaluated when it is still fresh. Cupping should always be executed with a high level of consistency and intention. 

There is no industry standard for a sample roaster, so companies tend to use whatever small roaster they have on hand or can easily purchase. For some, it’s an old-school open barrel Probat BRZ roaster. For others, a small-scale commercial drum roaster like our trusty MCR500 is the choice for samples. Increasingly, roasters across the world are turning to electric fluid bed air roasters like the Ikawa for a cost-effective way to taste green samples. So many variables are controlled in the sample roasting process, but the style and size of the roaster is a major point of inconsistency across the industry.

While small-volume electric sample roasters appeal to many at their lower price point, heat transfer can be limited by these roasters’ small size and heating elements. We suspected that ineffective sample roasting was potentially skewing roasters’ experience with green coffee evaluation, so we did what any reasonable coffee nerd would do: we set up a comparison cupping. 

Our Hypothesis

The goal of this experiment was to determine if the type of sample roaster meaningfully impacts a cuppers’ ability to evaluate green coffee samples and ultimately choose a specific green for purchase. More practically, we wondered if folks would select the same greens, pay the same price for them, and agree or disagree with their importers’ tasting notes and cupping scores regardless of what sample roaster they are using.

Methodology

We reached out to our friends at Cafe Imports and spoke to their Director of Sensory Analysis, Ian Fretheim, about what we had in mind. Ian prepared samples of 5 coffees on their standard sample roaster, a Stronghold S7, using their regular sample profile, and dropped them off with a green sample of each coffee. We then used the DiFluid Omni Roast Color Analyzer to gather internal and external color readings on Ian’s samples. 

Bryant prepared samples on our MCR500 as well as on an Ikawa V3 Pro. For those roasts, he attempted to match the colors to Ian’s samples so that all coffees were roasted within a small range of internal roast color. 

We hosted the cupping and were joined by members of Cafe Imports Sales and Sensory teams. The table was prepared with 5 sets of coffees, each set containing a cup of coffee roasted on the Ikawa, the Mill City Roaster, and the Stronghold. The coffees weren’t labeled so we didn’t know the origin or style of roaster until after we tasted everything.

Our Observations

There were several interesting takeaways from the comparative cupping. First and foremost, all of us agreed that our favorite (or highest-scoring) coffees were either roasted on the Mill City Roaster or the Stronghold. Many of our notes for the Ikawa roasts were that the sample lacked complexity, sweetness, or body, and in many cases, all three were missing.  

We also agreed that samples roasted on the MCR500, a traditional drum roaster, had good complexity and roundness and were, in many instances, the favorite roast of the set. Coffees roasted on the Stronghold, an electric hybrid-style roaster with conductive and radiant heat transfer, were perceived as having higher intensity though not always in the highest quality way.  

We discovered that coffees with intense origin or processing flavors, like the Ethiopia Dembi anaerobic natural on the table, were more similar across all three roasters. It seemed like coffees that were very fruit-forward or had very distinct notes might not be impacted as much by differences in roaster type. 

One of our earliest questions, when we started talking about this idea, was simply this: Even if a sample roaster doesn’t do as good of a job as others, could you still differentiate between quality and come to the same conclusion at a purchase cupping? In other words, if all my coffees are underdeveloped, would I still choose the same coffee and I would if they were all roasted beautifully? In this case, we were able to answer that question. 

There were 3 different washed coffees from Kenya on the table. After the coffees were revealed, most of the group indicated that they would select the second Kenya, an AA Regional Select coffee called Uteuzi Jimbo, over the other two options. After discussion, we agreed that we would still prefer this coffee if we’d only been able to choose between the Kenyas all roasted on the Ikawa, the Mill City, or the Stronghold. 

Here are my notes for that coffee:

Our group also wondered if we’d be drawn to the familiarity of the roaster we taste most often. Would the Mill City team drastically prefer the MCR500 roasts since they taste more like the coffees we cup every week? Actually, our whole group switched between preferring either the MCR500 or the Stronghold across the table, depending on the coffee. In a few cases, the Ikawa roast was preferred because of the way that it overemphasized acidity and created a “zippiness” in the mouthfeel. We did not notice a distinct pattern of people only liking coffee from the roaster they regularly taste. 

Conclusions

We’re a roaster manufacturer, so it’s no surprise that our biggest takeaway here is that your roaster matters. This exercise was helpful, though, in demonstrating to us the limitations of these simplified electric “prosumer” roasting systems. 

Cheaper roasting equipment is enticing when you’re getting into a new roasting hobby and you want to test out a small scale machine, but these smaller air roasters are not always able to showcase the best of what a coffee has to offer. It can be tempting to find a cheap option for your sample roaster, but remember that the greatest impact on your roasted coffee quality is the quality of your green coffee. To distinguish between green coffee options and ensure you pick the best option, it has to be roasted well. 

While professional, experienced tasters may be able to tell the difference in quality even in muted or underdeveloped cups, a less-skilled taster may pass on an incredible coffee if they aren’t able to taste the complexities and sweetness that’s unlocked in the cup. This information is meaningful for roasters, importers, and coffee producers, whose livelihoods often hang in the balance when purchasing decisions are made. We owe it to the shareholders of our industry to do our absolute best when it comes to pricing, scoring, and purchasing coffee, and in this case, the roasting system matters a lot.