How a roast profile is built: in the roastery with Emanuele

A sack of green coffee, on its own, doesn't taste of anything yet. Mandarin, honey, chocolate: everything you later find in the cup is in there, but under lock and key. The key is the roast profile, the "recipe" of times and temperatures that decides which flavours come out and which stay on the bench. Here at the roastery the roasting is done by Emanuele Tomassi, two-time Italian Roasting Champion (2018 and 2024) and 6th at the 2024 World Coffee Roasting Championship in Copenhagen. In this article we tell you how a roaster thinks when building a profile, and what it means for you, at home, with your moka pot or your V60.

What a roast profile is (explained without a thermometer)

Imagine cooking a roast. Same meat, but an oven at 160 °C for two hours or at 250 °C for forty minutes: you get two different dishes. The same happens with coffee, only in about ten minutes and with a lot more stress. The profile is the curve of the bean's temperature over time, and it's usually divided into three phases:

1. Drying. Green coffee contains water: in the first few minutes it loses it and turns from green to yellow. Rush this stage and the centre of the bean lags behind, bringing grassy, raw notes to the cup.
2. Browning (Maillard reactions). Sugars and proteins react, creating colour, sweetness and those aromas of caramel, hazelnut and toasted bread. This is the phase that builds the coffee's "body".
3. Development. Then comes first crack, a popcorn-like sound: the bean opens because steam has built up inside. From there on, every second counts. A few seconds more and the acidity softens, the body grows, the fruit gives way to chocolate. Too many, and bitterness arrives.

The whole game is in the balance between these phases: how long each lasts, how much heat you apply and when you decide to drop the beans. If you want to know what happens inside the bean at a chemical level, it's explained in what's inside a green coffee bean.

How a profile is built, step by step

A profile is never perfect at the first attempt. The method roasters use, at the roastery as in competition, is more or less this:

• Know the green coffee. Origin, variety, process, altitude: a high-altitude washed coffee is a hard, dense bean that can take more heat, a Brazilian natural is more delicate. Before switching the machine on, you look at the coffee's spec sheet (yes, just like the one on our bags: we covered it in how to read a speciality coffee label).
• Run some tests. You roast the same coffee with different profiles: faster, slower, shorter or longer development. During the roast the trier, that sort of spoon you can see in the photo above, is used to pull out a few beans and check their colour and aroma.
• Taste blind. The tests are compared by cupping, the standard tasting method of the speciality world: same dose, same water, same times, so the only difference is the roast. Fancy trying it yourself? Here's how to cup coffee at home.
• Choose and repeat. The winning profile is the one that best brings out the coffee's character. Then you have to repeat it exactly, batch after batch, which is the least romantic and hardest part.

What changes for you: light, medium and resting days

OK, but you don't have a roaster in your kitchen (and if you do, respect). Here's what you take home from all this:

• Light roast = more fruit and acidity, more aroma. At its best as filter (V60, Chemex, AeroPress).
• Medium roast = more body, sweetness and chocolate. Your friend for moka pot and espresso, because it's more forgiving.
• Let the coffee rest. After roasting, the bean releases carbon dioxide: use it straight away and the extraction is uneven. Our advice is at least 5 days for filter and moka pot and 15 days for espresso. All the details are in why freshly roasted coffee needs to rest.
• Check the roast date, not just the best-before. It's the most useful information on the bag.

Same coffee, two profiles: Blend Futuro

If you want to see first-hand (or rather, taste first-hand) how much the profile matters, Blend Futuro is perfect, because it comes in two roasts: light and medium. Inside there's 50% washed Peru Añas Blues, 30% natural Ethiopia Makhore and 20% natural Brazil San Rafael. In the cup: mandarin, strawberry, honey, dark chocolate, yellow plum, caramel and hazelnut. With the light roast you taste more of the fruity side of Peru and Ethiopia; with the medium, the cocoa and nutty side of Brazil comes out. And we roast it after you order, with the date on the bag. The best game? Get both and taste them side by side. Discover Blend Futuro.

In brief

• The roast profile is the curve of time and temperature: drying, browning, development.
• It's built with tests, the trier and cupping, then repeated exactly every time.
• Light for filter, medium for moka pot and espresso.
• Rest: at least 5 days for filter and moka pot, 15 for espresso.
• On the bag, check the roast date first of all.

Kiss my beans!
Heartfelt thanks, the Tomassi Family