How Roast Profile Shapes Coffee Body: A Roaster's Guide

A friend of mine never misses a chance to point out the body or mouthfeel of a coffee. He believes it is one of the qualities customers pick up on almost immediately, and I tend to share that view.

When we taste coffee in the specialty sector, we often push customers into the deep end right away. We dissect the differences between citrus fruits, name a specific flower species, or reach for a descriptor that is unusual and startling.

Most conversations about flavor notes sail far above their heads. Yet with a bit of gentle guidance and some well-chosen examples, nearly anyone can join in a discussion about a coffee's body or texture.

Defining Texture

Body refers to a coffee's weight, texture, and mouthfeel. It appears on the Specialty Coffee Association (SCA) cupping form as a green coffee attribute, can shift during brewing, and is frequently tied to the processing method used on the farm. One thing we as roasters need to keep in mind, though, is that the way we roast a coffee has a substantial effect on its body.

I would like to offer a concept from my roasting handbook, Modulating the Flavor Profile of Coffee: One Roaster's Manifesto. The idea is that body development is connected to the Maillard reaction during roasting—more specifically, to the formation of melanoidins.

Melanoidins are brown, high-molecular-weight polymers produced during the Maillard reaction. In their book Espresso: The Science of Quality, Andrea Illy and Rinantonio Viani cite research that associates melanoidins with texture. Interestingly, molecular weight and viscosity are also related. In simple terms, a higher molecular weight produces greater viscosity. It follows, then, that more melanoidins—formed through the Maillard reaction—would raise the overall molecular weight, which in turn would increase viscosity and create a sense of weight or thickness in the mouthfeel.

What makes this information so useful is that we can, within limits, influence how the Maillard reaction unfolds in our roasters by adjusting our profiles. The Maillard reaction starts at roughly the point when you see the beans turn from green (pale green) to yellow in the roaster.

These reactions carry on until the bean exhausts its reactants, or until you cool the beans by dropping the coffee into the cooling tray or starting the cooling cycle. Depending on how efficient your cooling apparatus is, they may continue a little afterward.

In my own experiments and cupping sessions, I have observed that the longer the Maillard reaction is permitted to continue, the more intense the experience of body (texture, viscosity, thickness). Conversely, the shorter the time given to the Maillard reaction, the weaker the intensity or perception of body.

A Weighty Responsibility

Naturally, far more is involved in how this process takes place and how we can steer it—I explore that at length in the book—but I want to talk about how these ideas might be put to use.

First, it is remarkable that we have this kind of control. If you approach coffee roasting and profile development this way, you are not limited to a single expression of body. You can take a coffee and work it toward the texture you want. It is important to remember that every coffee has a range within which it can exist, and within which you can modulate its attributes, so sourcing matters a great deal—but the essential point is that the control is yours.

Second, that control comes with real responsibility. Body is a scoring category not only on the SCA cupping sheet but also on the Q grader and Cup of Excellence score sheets. These forms classify the overall quality of green coffee and shape buying and pricing decisions. As roasters, you influence how body is expressed, so you must be diligent about recording your roast data in order to be fair to the coffee.

One method we use that works well is this: during sample roasting, I note the time when the color change begins and record the duration through to the end of the roast. That way, after cupping the coffee, I can understand how the roast affected body and adjust how I judge it—or even conclude that a re-roast is warranted.

Take charge of your roast. Using the length of the Maillard reaction to govern how intensely body shows up in the cup is only one of the many ways you can manipulate your coffees. We should aim to be informed, deliberate, and precise, because every choice we make shapes the final flavor and quality of the cup.

Rob Hoos is the head roaster for Nossa Familia Coffee and consults through his company, Rob Hoos Coffee Consulting