Coffee roaster: what are the specific categories of common coffee roasting machines?

1. Hot air coffee bean roaster

The hot air type bean dryer uses the blower to absorb the air, and then let the air pass through a heating coil to raise its temperature. Hot air is used as a heating source to bake coffee beans. Hot air can not only provide the temperature needed for baking, but also use the power of airflow to stir coffee beans, killing two birds with one stone.

Advantages: high thermal efficiency, fast heating, relatively uniform heating of raw beans, easy to control.

Disadvantages: because of the high heating efficiency, it is easy to lead to excessive heating, resulting in beans "entrainment", and too high temperature is easy to make the caramelization reaction is not sufficient.

Taste characteristics: the acidity is obvious, the taste is relatively clean and simple, but the taste is not rich enough and lacks depth, and deep baking is easy to produce irritating taste.

2. Direct-fired coffee bean roaster

As the name implies, the direct fire is to heat the coffee beans directly with a flame. Up to now, the "fire" of direct fire not only includes general flame (including gas furnace fire and charcoal fire), but also includes infrared and electric heating pipe.

Advantages: the baking time is long, so the caramelization reaction is sufficient and the flavor is rich.

Disadvantages: it is easy to cause uneven baking, and if the heat is not well controlled, it is also easy to scorch coffee beans and form a scorched bitter taste.

3. Semi-direct fire and semi-hot air coffee bean roaster

The baking method, which combines the advantages of direct fire and hot air, is the mainstream of commercial baking machines at present. Semi-direct-fire baking is actually similar to direct-fire baking, but because there are no holes in the outer wall of the baking container, the flame will not directly touch the coffee beans. In addition, a ventilation device is added to introduce the hot air from the outside of the baking container into the baking room to improve baking efficiency. Another function of this ventilation device is to suck out the exfoliated silver skin (the film attached to the outer layer of coffee seeds). Prevent the silver skin from burning because of high temperature in the baking room, thus affecting the taste of coffee beans.

Semi-direct fire semi-hot air machine has the advantages and disadvantages of both direct fire type and hot air type, but its heating mode is changed according to the adjustment of hot air and boiler speed. The larger the hot air, the faster the speed is, the closer it is to the hot air type; on the contrary, the closer it is to the direct fire type.

Source: happy Bakery Network