The coffee roasting process introduces how coffee is roasted to highlight the desired flavor.

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The whole roasting process of coffee from raw beans to cooked beans, STEP 1: from bean feeding to T.Point feeding is the initial stage of roasting. After the beans are put into the preheated drum, the drum temperature will drop immediately until the drum temperature and the bean temperature reach balance. Generally speaking, it is appropriate to reach T.Point (recovery point) within 120 seconds, STEP 2: from T.Point to Yellow

After T.Point, raw beans enter the endothermic stage. 70% of the bean weight is made up of insoluble (Insoluble) cellulose (Cellulose). In order to transfer heat to the inside of the bean, the water conductivity is used. If the bean water content is low, the time to reach the Yellow stage will be shorter, on the contrary, if the bean water content is high, the time to reach Yellow will be longer. STEP 3: from Mena reaction (Maillard Reaction) to 154. C

The baking temperature reached 154. At C (PS: every bean roaster will not be the same), the internal and external temperature and pressure of coffee roasting beans are at about the same stage. Sugar components are decomposed into reducing sugar (Reducing sugar) by adding water, which combines with amino acids (Amino acids) to produce Melanoidine and volatile organic compounds, which is the Mena reaction. Through this process, coffee beans will produce flavor changes. STEP 4: from caramelization (Caramelization) 160.C to 200.C

At this stage, beans are caramelized by thermal decomposition, which begins to reduce sweetness and transform into a very complex flavor (Aroma). At the same time, due to the increase of CO2 pressure and vapor pressure, the beans began to produce a fever reaction.

STEP 5: coffee roasting from the first explosion to 194Murray 5.C

When the vapor pressure and CO2 pressure inside the bean accumulate, the first burst (1st Crack) occurs. The "blow holes" produced at this time becomes the outlet for the discharge of Flavor compounds inside the bean. At this stage, the beans are completely converted to a febrile reaction. STEP 6: from the second explosion to 220. C

The CO2 pressure accumulated due to thermal combustion is released outward, and the beans burst again, which is called the "second explosion". At this stage, the cell structure of beans begins to be destroyed, and the interior begins to be coked or carbonized (Carbon). From then on, the flavors attached to Dry Distillation (Resin, Spice, Carbon) will appear and produce obvious bitterness.

STEP 7: from bean production to cooling (Cooling)

Although the beans begin to cool immediately after they are produced, the temperature of the beans will not drop immediately. Because the temperature inside the bean can be maintained at a high temperature for a period of time, the high temperature maintained by the bean itself may change the degree of baking and may lead to the volatilization of the aromatic flavor. therefore, rapid cooling is a very important step to maintain the flavor. After the coffee is roasted, the beans are forced to cool. Then carry on "raise beans", emit carbon dioxide, and the flavor is more mature.