Introduction of roaster roaster is mainly divided into four categories

The roaster is mainly divided into four types: direct fire type, semi-hot air direct fire type, hot air type and electric type.

1. Direct fire type

Direct fire is the earliest baking tool, that is, raw beans are roasted in a hot drum and then transferred to the cylinder. The built-in motor keeps running the drum and stirring the coffee beans in the drum, trying to make each coffee bean come into contact with the hot iron evenly to achieve the goal of balanced roasting.

Disadvantages:

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

● burns the outside of the drum, but the heat dissipates in the air, so it's a pity that it can't be used well.

● when the raw bean touches the inner wall of the drum for too long, it is easy to scorch, resulting in bitterness and scorching taste.

The silver film or silver skin produced by ● during baking will be left in the tube, which is easy to attach to the surface of coffee beans and make the flavor cloudy.

two。 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.

3. Hot air type

In the 20th century, some people thought of using hot air to bake coffee beans. In addition to using hot air to bake coffee beans without iron barrier, the heat source can be transmitted directly to raw beans to improve baking efficiency. The Thermonro roaster JadezBurnsThermalo made by Burns Company in the United States in 1934 is a kind of hot air type machine. There are still some large baking plants in the United States and are still using this kind of roaster.

In addition, the wind bed roaster Fluid-BedRoaster can still be seen in the market. Here can be briefly introduced: the structure of the hot air baking machine still adopts the drum design; the raw beans are turned by rolling to achieve balanced baking. In 1976, American Michael. Schweitz MichaelSivetz designed the air bed roaster Fluid-BedRoaste, which allows air to blow up and down in an airtight container, allowing raw beans to float up and down until the baking is completed, and then poured into the cooling tray outside the container to cool.

4. Electric heating type

Electric heating type is the electric heating wire heating drum, this kind of power is relatively large and better electricity, the disadvantage is that the electric heating pipe for a long time value voltage instability will lead to damage, the loss of heating function, the equipment will be paralyzed. In fact, do not worry too much, almost every city's electrical wholesale market can be customized heating tube, so that the machine back to work.