Danielmachine guideline of coffee roasting for beginner.
Learn about the coffee roasting process
Coffee roasting is a complex process that involves carefully applying heat to the beans. The process of roasting coffee along with the effort to transform the basic things contained in each bean. Including: sugar, protein, acid, etc. Through the roasting process, the coffee transforms into the attractive aroma of roasted nuts. Be it malt, chocolate, fruit, berries, flowers and more. Everyone pays great attention to each cup of coffee, combining scientific data recording in the coffee roasting process. With intuition and experience to bring out the most optimal flavor and balance.
At the beginning of each batch of raw coffee is fed into the feed system of Danielmachine roaster. When the internal air temperature of the roaster reaches 500F. The batch is then dropped into the hot, rotating drum to begin the roasting process. Inside the drum there are many stirrers to throw the coffee through the air. This is similar to how dryers work.
The coffee phase begins to change color
During the first 5 minutes, a high amount of heat is applied to bring the coffee to roasting temperature. This step must be done quickly enough to keep the moisture inside. But not so quickly that the outside of the bean is in danger of scorching. The color of the coffee changes from green to yellow.
Over the next 5 minutes, the coffee undergoes changes in low roasting temperatures (from 300F to 350F). The premise for taste and aroma will develop at higher temperatures. They are developed and the humidity, pressure and temperature inside are more carefully controlled. The color gradually changes from yellow to light brown.
Coffee roasting process – the first crack appears
For the last 2 to 5 minutes (depending on the type of coffee and degree of roasting). The full flavor of the coffee is brought into play. At about 360F, the “first crack” occurs – a popping noise occurs as each pea expands under the pressure of carbon dioxide. And steam is created from chemical reactions inside the bean. At this point, the internal pressure drops as these gases are allowed to escape. This results in beans with the ideal internal temperature, pressure and humidity for flavor development.
Switch coffee bean flavor
Between 360F and 395F, the sugars and amino acids in coffee react at a rapid rate to create the final flavor of the coffee. The flavor of coffee roasted at a "medium roast" is derived from the carmelization of the sugars and the reaction of sugars and amino acids in the "mailard reaction". It resembles the flavor developed through the browning of the meat on the grill. During this stage, the coffee turns darker brown and the aroma develops into a grain, cocoa-like and malt character.
Every coffee has its exact final temperature and roasting time. Both were developed through a combination of intuition and experimentation by the roasting team. For example, a Yirgacheffe coffee might be roasted to 380F while a Honduran Espresso would be roasted to 389F.
Dark roasting stage
Coffee roasted at temperatures above 395F is considered dark roast. At these temperatures, the aroma and taste developed in the early stages of combustion. And new aromas that are aromatic, smoky and spicy will develop. Sweet and sour tastes are replaced by the development of bitterness. Most dark-roasted coffee beans grow from 410F to 420F. There is an opinion that the darker the coffee beans, the stronger the flavor. We do not disagree with anyone's opinion. To create a perfect roast it depends on the taste of each person. For other roasting stage, please check more on website www.danielmachine.com