Types of coffee roasters

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

However, the heat dissipates in the air, so it is a pity that it can not be made good use of.

● 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 Van Guban VanGulpen devoted his whole life to the improvement and manufacture of drum roasters, thus leaving many ideas for posterity, in one of his inventions, coffee beans were promoted to be brought into baking with hot air.

The Perfekt roaster made in Germany in 1907 began to introduce this concept. It uses gas for heating, and there is an air pump that brings half of the hot air into the drum and the other half to the outer barbecue drum. At present, German drum baking still has some reviews in the industry.

On the other hand, the German Boroba Probat drum roaster can be said to be spread to the baking industry all over the world.

Generally speaking, roasters use gas or electricity as a heat source, but Derek Diedrich, of Idaho, Idaho, took the lead in using gas-activated infrared heat source Gas-Infrared in 1987 to make temperature control more accurate, well received and become the first brand in North America.

Today's drum-type roasters almost all use semi-hot air direct fire type, on the one hand directly barbecue the hot drum with fire source, on the other hand bring hot air into the drum, blow into the hot air in the drum, which can not only increase the heating rate, but also blow away the detritus, so as to produce balanced and clean coffee beans.

However, due to the different structural design, and each boasts the best design, in fact, it is most important to understand the truth of coffee roasting. Roasters of the same grade and different brands will not cause too many differences.

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. However, some people have long thought why not use hot air to move raw beans, so that beans can float up and down, breaking the concept of rollers.

It was the American Michael in 1976. 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 in the container until the roast is finished, and then poured into the cooling tray outside the container to cool. Michael is often found on the website of the selected Coffee Association of America. Schweizi's comments.

There are similar baking methods of design and construction in Australia; RollerRoaster, a roaster created by Iomberstein IanBersten and marketed in Australia, is also well known. In the general baking process; the water in the beans is evaporated less and less, and the quality becomes lighter and lighter, so the weight of the roaster will fall faster and accept the hot air baking again, so repeatedly, that is, the coffee beans can be baked evenly, but without the smoldering of the metal drum, some people will think that there is always one less taste.

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. There is no need to worry too much about the custom heating tubes that can be customized in almost every city's electrical wholesale market, so that the machine can resume its working condition.