Australia's famous baking manager tells the secret of coffee roasting how to roast coffee beautifully

Who would have thought that the coffee we drink every morning is originally the seed of fruit. How does an ordinary seed turn into brown, fragrant coffee? Today we invited Dylan Hewitt, the coffee manager of Wide Open Road, to have a cup of coffee with him and discuss the topic of coffee roasting. Dylan is not the kind of man who likes to play with tools in the gym. He prefers to play with his blended coffee and shop around the world for high-quality, unique coffee items.

"the core of baking is easy to understand. You have a pile of raw coffee beans and a stove. As the temperature of the beans rises, a series of chemical reactions take place inside the beans, and the beans gradually turn brown." Dylan said.

But is baking really that simple? Of course not! Dylan added: "although the principle is easy to understand, the baking process is very complex, and the higher your requirements, the more difficult it is to bake."

Generally speaking, the purpose of coffee roasting has not changed in the past hundred years, and the two main factors in roasting are temperature and time, so how to balance the relationship between them has become the key to successful roasting. Usually, roasters use a natural gas-heated drum roaster to bake coffee. During the roasting process, coffee beans undergo a series of chemical reactions, and green raw beans gradually turn into brown ripe beans. The main reason for the color change is the exudation and coking of sugar in the beans.

"when I first started learning to bake, I focused on time control. Normally, the first burst of coffee beans occurs in about 9 minutes, and the coffee can be made two minutes after the first burst. " When the first burst occurs, there will be a loud explosion in the furnace, which sounds like popcorn. The principle of bursting is that coffee beans expand rapidly, causing an explosion by the accumulation of water and carbon dioxide, while releasing a small amount of water or steam. The first burst can wrinkle the surface of the bean body, thus increasing the surface area of the bean body. In some cases, the coffee will burst for a second time, and the sound of this burst is softer, indicating that the structure inside the bean body is beginning to disintegrate.

"now we use software to strictly monitor baking time, and with the data, we can communicate and discuss with other bakers. We can calculate mathematically the whole time it takes for coffee to mature from raw beans to maturity. Some people think that this time should be calculated from the first burst of coffee, while others think that the whole process of roasting should be taken into account. In any case, monitoring time is an important means to master the quality of baking. "

"although the principle of baking has never changed, the technology of baking is constantly improving, which is a strong guarantee for us to pursue higher quality of coffee."

As the manager of the coffee business, Dylan knows the "baking curve" very well. When taking over a batch of new beans, Dylan repeatedly adjusts the baking parameters until the quality reaches the desired effect, then records the parameters and asks his bakers to bake them instead. As for the "baking curve," Dylan said: "baking is actually a process of specifying a formula." As for the relationship between temperature and time, Dylan said: "you need to know when it comes out of the oven and how much the temperature is set." Different varieties of coffee behave differently in the roasting process. Indonesian coffee is drier and more crisp, so we cook slowly over low heat. Due to the different water content, the rate of caramel reaction will change. Hard, high-density beans have more cells than light, low-density beans. What we need to do is to balance the baking degree inside and outside the bean body, which is the same principle as baking cake! The cake is paste on the outside and raw on the inside. it won't work like this; if it takes too long to bake, it won't even taste too dry inside! "

During the baking process, the baker will repeatedly check the heat size, baking time and temperature in the oven, as well as the color, sound and aroma of the coffee. In order for the roasted coffee to cool fully, the roaster pours the coffee into a continuously stirring cooling tray, and it is important to note that even if the coffee enters the cooling plate, there is still a small amount of residual temperature in the beans, which means that the roasting process of the coffee is not over.

Of course, Dylan's job is not just to develop roasting recipes, he is also responsible for purchasing and importing individual coffee beans from around the world, as well as making blended coffee. He will cup test each batch of purchased beans, in order to ensure that the quality of the beans is perfect and mellow!