Introduction to the working principle of coffee full hot air roaster and the price of construction material

Then put the selected beans into the roaster, connect the power supply, turn on the switch of the roaster, and the display screen will show 0. The program can set the baking temperature and time for three stages, but I didn't set it here. I just press the ROAST key to start. It will bake according to the last baking time and temperature.

At first, it is the steaming stage, and the water in the beans begins to evaporate as the temperature rises.

As the temperature continues to rise, the silver skin begins to fall off. During baking, press ROAST to display the temperature.

The color of the beans has begun to change to a light brown color.

The temperature continues to rise. The color of the beans has become a little darker in cinnamon.

According to my own experience, Mantenin is best baked to medium and micro depth, and every time I bake to the surface of the beans, the oil just comes out. Press the COOL key in the lower right corner to enter the cooling phase. The time that the machine has been set is 3 minutes.

Although it has gone through the cooling stage, the coffee still has a little residual temperature. Blow it with a fan to accelerate the cooling.

After baking and then hand-selected, this bean is good, basically can not choose any mixed beans. Weigh 100g after baking

Commercial roaster

The manufacturing principle of commercial roaster is mainly divided into three types: direct fire type, semi-hot type and hot air type. At present, the latter two kinds of roasting are the best and are the mainstream in the selected coffee market.

1. Direct fire type

The earliest baking tools used by human beings are all direct fire, that is, the drum is heated by fire, and then heat transfer to the raw beans in the cylinder. Although, the motor keeps turning the drum and stirring the coffee beans in the cylinder, in an attempt to let each coffee bean touch the hot iron wall evenly, so as to achieve the goal of balanced baking. However, this baking method still has many disadvantages: the heat conduction speed of iron is not fast, so it must take more time to complete baking; on the outside of the burning drum, the hot gas dissipates in the air, which is a pity that it cannot be well utilized; when the raw bean touches the inner wall of the drum for too long, it is easy to be scorched, resulting in bitterness and scorching taste. When baking, there are a lot of crumbs burst out, left in the tube is easy to adhere to the surface of coffee beans, will make the flavor become chaotic.

2. Semi-hot air direct fire type

Between 1870 and 1920, the German Fan Guban improved and manufactured the barrel roaster. In his baking theory, he refers to coffee beans that bring hot air into roasting. In 1907, the German-made Perfekt roaster began to introduce this concept, using gas heating, there is an air pump, half of the hot gas into the drum, half to the outer barbecue drum. Up to now, roller baking in Germany is still widely used, and the country's Probat drum roaster is famous all over the world.

The general roaster uses gas or electricity as the heat source. In 1987, Derek Company of Idaho took the lead in using the infrared heat source activated by gas, which made the temperature control more accurate and well received, and became the first brand in North America.

Today's drum roasters are almost all semi-hot air direct fire type, on the one hand directly heat the drum with the fire source, on the other hand bring the hot air into the drum. The hot air blown into the drum can increase the heating speed and blow away the debris, thus producing balanced and clean coffee beans.