April 19, 2017

Effective Experimentation Methods for Coffee People


Curiosity is among my favorite human instincts. It drives innovation, encourages thinking outside the box, and is spurred by such a simple question that even a two-year-old can ask it: “Why?”

Of course, answering the why – whether in life in general or about coffee in particular – is never as easy as asking. But we need curiosity in the coffee industry, whether we’re producers, roasters, baristas, or consumers. It spurs us to improve processing methods, create new brewing devices, and more.

So, let’s look at some strategies for more effective question-asking and answering.

Spanish Version: Efectivos Métodos de Experimentación para Gente de Café

coffee experimentation

An experiment in full swing. Credit: Socratic Coffee

1. Be More Specific

Simply put, asking “why” isn’t enough. Start asking more “how,” “which part,” and “to what extent” types of questions.

For example, if you’re curious about why espresso flavors are affected by roast degree, ask: how do changes in heat application during a roast affect extraction percentage? What part of the roast is most critical for perceived sweetness as espresso?

By refining your query, you’ve taken an esoteric question and made it specific, measurable, and real-world applicable. That’s the difference between idle wondering and active investigation. Giving yourself the right question is key to taking action.

coffee experimentation

Putting research into practice. Credit: Populace Coffee

2. Take Stock & Minimize Variables

Before jumping into the question, you’ll need to pick apart the details. What do you already know? What do you think the answer is, based on your experience? What exactly are the gaps in your knowledge?

Let’s go back to the question above. You might already know that the first few minutes of a roast are mostly related to drying the green coffee out. This means you can focus on the later segments of a roast. Assuming you’re not an MIT grad with a firm grasp on the thermodynamic principles behind Maillard reactions, you’ll have to limit your research to whatever tools, observation skills, and reporting abilities are at your disposal.

Similarly, if you’re interested in figuring out why soy milk curdles in some coffees but not others, take stock of what you already know. Do you have samples of both? Do you have notes on the temperature, brew strength, origin, or roast level of the coffees in question?

By taking stock of what you have already observed, you can narrow your focus and get better results in the end.

coffee experimentation

Take stock of your variables. Credit: Cafeolgía

It’s at this point that you’ll also want to work out your control group. If your experiment involves the effect of the coffee to water ratio on perceptions of acidity in a particular coffee, for example, start with a standard ratio. You’ll want a well-annotated standard against which to compare your experimental styles.

Lastly, focus your research on as few variables as possible. Changing just one or two factors will help to eliminate confusion. The more variables, the more opportunities to make mistakes or misattributions.

For example, if you’re interested in figuring out the effect of fermentation time on a washed coffee, start with two batches and don’t use different cultivars, batch weights, or timeframes. Make everything in the experiment exactly the same (or as close as possible), except for the variable you’re examining. You can always repeat the experiment later with different variables.

coffee experimentation

Have a control group. Credit: Rusty Bridges

3. Measure, Observe, & Repeat

The scientific community is obsessed with the repeatability of experiments – for good reason. Without the ability to replicate results, research benefits no one. Repeatability makes theoretical ideas practical for everyone’s benefit, and serves as proof the conclusions are valid.

With that in mind, you’ll need to be a stickler for details. What is the exact amount of coffee you’re using? Exactly what is the temperature of the coffee? Or of the environment? Measure everything you can think of… within reasonable limitations.

Then do it all again. Were the conditions the same? What about the results? If not, you’ve found another “why” question to start investigating.

coffee experimentation

What differences are you finding? Credit: Matty De Angelis

SEE ALSO: Jen Apodaca: How to Improve Your Roasting Skills

4. Analyze, Then Progress

What worked, what didn’t, and why do you think the experiment led to those results? Are there data trends you can trace? Was there a definitive answer, or just some suggestions of a probability?

In many cases, you should be prepared for foggy results that tend to raise more questions than they answer. That’s good. It means you’re digging in the right direction. Easy answers are rarely adequate, and can lead to overconfidence. New questions will guide your research further, slowly refining your results and giving more robust answers.

coffee experimentation

Experimenting with different brewing ratios. Credit: Matty De Angelis

5. Guard Against Bias

There are few greater threats to meaningful research than personal bias. Predisposition towards a certain answer can take many forms – it’s normal to want to confirm your suspicions. There are even ways that our own minds will try to unconsciously uphold pre-existing constructs. Not all bias is intentional.

There’s one easy way to avoid confirmation bias – involve a research partner. Two heads are better than one. Keep your control and experimental samples blinded (i.e. unlabeled and unidentified), and have an open mind, being reasonable with your expectations.

Managing your expectations is crucial, because what works for you in your particular environment and circumstances may not work for everyone everywhere. You’re also naturally going to want to get a perfect answer to your question, which is pretty rare.

For example, let’s say you settle on a conclusion that when you’re roasting Brazilian dry-processed coffee, using less heat during first crack produces more soluble coffee than using high heat. Shots pulled with the low heat sample at a 2:1 water/coffee ratio are always sweeter than the high heat sample.

Even though you’ve isolated many variables (dry process, Brazil, low heat during first crack, water to coffee ratio), there are still assumptions in your results. Implicit in your conclusion are the make/model of your machinery, the ambient temperature and humidity of your environment, and even your personal preference in terms of flavor style, just to name a few.

Open-minded discussion and analysis, just like starting with good questions, will spur progress and encourage others to join in the investigation.

Please note: Royal Coffee, Inc. is a sponsor of Perfect Daily Grind.

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