On every step of the value chain these machines are essential! In origin for tasting crop quality and purchasing, at destination when buying, and for roasters for when they're developing a new crazy profile! There is no perfect roast, and actually, people will not buy a coffee with a different roasting profile! Therefore, it is not only important to understand how you like you're coffee but also how this has been developed for YOU!
1. DRYING STAGE: Coffee has a humidity of 8–12% which firstly needs to by dried. Typically lasts 4–8 minutes with traditional drum roaster and he temperature in the end of drying stage is typically 160 ⁰C. Here, one needs to be careful not burn the beans by having too much heat in the start!!!
2. BROWNING STAGE: Delicious smells like toasted bread and hay start to arise by this point. Now, the Maillard reaction is taking place reducing sugars and amino acids making hundreds of different aroma and color compounds known as melanoids. Roasters at the stage will want to slow down the roast to ensure flavour development. By the end of browning stage the coffee starts to pop - also known as the first crack!
3. DEVELOPMENT OR ROASTING STAGE: During this stage the wanted aroma compounds are developing. If one does not slow down the roast at development stage, we ca easily get coffee that is smoky tasting and the flavour is too sharp. Typically 15–25% of the total roast time is spent in during step depending on the desired flavour profile and roast degree!