Introduction of coffee roasting stage introduction of coffee roaster introduction of roasting degree of different coffee beans

To sum up, coffee roasting is a science. The age, density, hardness and moisture content of raw beans will affect the quality of roasted coffee. Even the relative humidity and temperature on the day of roasting can not be ignored.

Just roasted coffee beans, it is best to leave for 2-5 days, let a large amount of carbon dioxide out of the coffee beans after drinking will be more smooth, Hong Kong coffee will choose an one-way breathable valve aluminum foil bag to preserve coffee beans, can prevent air entry caused by oxidation, but also let carbon dioxide out, ensure that coffee beans remain fresh in the best condition pay attention to changes in color and taste-coffee beans color will continue to heat up From green to light brown, and then a small amount of oil is reddish brown, and then a large number of oil is shiny dark brown. At this point, you can no longer bake, otherwise the coffee oil on the surface of the beans will dry, and there will be a lot of smoke and burning smell. Pay attention to the sound changes-the coffee beans will burst twice during the roasting process, and the first burst sound is lower. It means that at the beginning the starch begins to turn into caramel, and the water evaporates with carbon dioxide. The second burst sound is more violent and sharp, this is the sound of coffee bean cell fiber fracture, at this time should immediately stop heating, and as soon as possible with cold air to lower the temperature of the bean. The time of the first explosion and the second explosion can be very different, so when baking different beans, it is necessary to find out the least carbonization that is most suitable for the bean's baking conditions-during the baking process, some ingredients will also be carbonized off, forming a bad bitter substance, so, when the second explosion is completed, stop heating and reduce the carbonization to the lowest at the same time. Caramelization is an important factor affecting the flavor of coffee. Because raw beans absorb a lot of heat when roasting, there is the first loud sound (1st cracking). At this time, the sugar begins to convert into carbon dioxide, water continues to evaporate, and the aroma of coffee gradually emanates and forms coffee oil. This pyrolysis reaction can last until the second explosion (2nd cracking), but when the second explosion is completed, the temperature of the bean should be lowered with cold air as soon as possible, so that the highest caramelization can be obtained.