Introduction of coffee roaster

Baking machine is mainly divided into 4 categories, direct fire type, semi-hot air direct fire type, hot air type, electric type.

1. direct fire

Direct fire type is the earliest use of baking tools, that is, the use of fire to bake hot drum heat transfer to the barrel of raw beans. A built-in motor rotates the drum constantly, stirring the beans in the drum, trying to make each coffee bean evenly contact with the hot iron to achieve the goal of balanced roasting.

Disadvantages:

● The heat conduction speed of metal is not fast enough, and it takes more time to preheat the drum.

● It is a pity that the outside of the drum is burned, but the heat dissipates into the air.

● When raw beans touch the inner wall of the drum for too long, they are easily burnt, resulting in bitter and burnt taste.

● The silver film or silver skin produced during baking will remain in the barrel and easily adhere to the surface of the coffee beans, making the flavor turbid.

2. semi-hot air direct fire type

Between 1870 and 1920, the German van Guben improved and manufactured the barrel baking machine. In his theory of roasting, 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, with an air pump that carried half of the hot air into the drum and half to the outer barbecue drum. To this day, Germany's roller baking is still widely used, and the country's Probat roller baking machine is famous all over the world.

General roasters use gas or electricity as heat sources. Derrick Corporation of Idaho pioneered the use of gas-activated infrared heat sources in 1987 to achieve more accurate temperature control and was praised as the first brand in North America.

Today's roller baking machine is almost all semi-hot air direct fire type, one side to the fire directly to heat the roller, one side will be hot air into the roller. The hot air blown into the drum increases the heating speed and blows away the crumbs, thus producing balanced and clean coffee beans.

3. hot air type

In the 20th century, some people thought of roasting coffee beans with hot air. In addition to the iron barrier, the heat source can be transmitted directly to the green beans to improve the roasting efficiency. The Jadez Burns Thermalo, a 1934 American baking machine made by Burns, is a hot-air model, and there are still some large baking plants in the United States that still use this type of baking machine.

Fluid-Bed Roaster, an air bed roaster still available on the market. Here is a brief introduction: the structure of the hot air roaster is still designed with a roller; by rolling to flip the raw beans, to achieve balanced baking. In 1976 American Michael. Michael Sivetz designed the Fluid-Bed Roaste, an air-bed roaster that blows air up from below in an airtight container so that green beans float up and down inside the container until roasting is complete and then poured into a cooling tray outside the container to cool.

4. electric heating type

Electric heating is heating wire heating roller, this power is relatively large, the disadvantage is that the value of the electric heating tube for a long time unstable voltage will lead to damage, loss of heating function, equipment will also be paralyzed. In fact, there is no need to worry too much, almost every city's electrical wholesale market can be customized heating pipe, so that the machine returns to work.