Roast profile is usually divided into three parts – Drying, Maillard and Development. In this article I would like to introduce you to the first part of roast.
Drying starts when beans are dropped into the roasting chamber or roasting drum and ends around 150 Celsius degrees (depending on probe), when beans turn fully yellow in color. During this stage of roast not many chemical changes happen. What is mainly happening is evaporation of water content from the surface of the beans and the start of building up pressure inside beans that will determine how fast chemical changes will take place in two following stages. This phase usually lasts around 5 minutes (depending on batch size, roaster, desired profile etc).
As a roaster you may wonder if it actually affects the roast or not? Well, it does affect the roast. When you decide to stretch the drying phase for too long you may end up with an underdeveloped roast. In such roast beans didn’t receive enough heat (energy) to build up enough pressure inside them to roast effectively. It will also stretch the rest of your roast due to the small amount of heat applied. You can try to apply heat later in the roast but when beans have less moisture they are more fragile and they can end up scorched.
On the other hand, being too fast and too aggressive during this stage can result in very fast pressure build up that has to be released somewhere. It is usually released via the tip of the bean resulting in a tipping defect that adds a layer of smokiness (taste associated with dark roasting) to your lovely fruity beans.
To sum up, unless you don’t do anything extreme (small batch with very high heat or soaking for too long) you will be fine with this stage. Aim for 4 – 6 minutes of drying phase. If you have any questions feel free to contact us.
Our step-by-step roasting guide has been design for you by Aleksander Smet, 2022 Polish Roasting and Cup Tasters Champion.
