Effect of Bean Mill on Coffee Flavor advantages and disadvantages of two kinds of Grinding plates

Like to drink coffee, is a hobby, like bubble coffee shop, is a mood, like to make coffee, is a way of life.

In China, more and more people begin to fall in love with coffee, fall in love with coffee life, baristas constantly study how to brew better coffee, constantly try different flavors of coffee beans from all over the world, different tastes brought by various brewing appliances, and personality shown by various brewing methods.

Among the factors that determine the taste of coffee brewing,"beans","grinding" and "machine" are hardware factors, and "technology" is a software factor. Today, Chongqing Bairista Coffee West Point Training School will discuss in detail the influence of "grinding" on coffee taste.

At present, there are many kinds of bean grinding machines on the market, but they can be divided into parallel grinding, conical grinding, roller grinding, ghost tooth grinding, machete grinding and so on. Roller mills are mostly used in large factories to crush beans like noodle presses, which have high grinding efficiency, but are not suitable for cafes; while machete mills are mostly household simple bean grinders, which use the power of blade rotation to chop beans, with extremely low uniformity and high heat generation, which is very unfavorable for coffee flavor extraction. Parallel grinding and conical grinding are the mainstream grinding discs at present, and the differences are as follows:

In general, the advantages of parallel grinding disc are fast speed, fast grinding, more uniform, the disadvantage is easy to heat, relatively short life; and the advantages of conical grinding disc is not easy to heat, long life, the disadvantage is slow speed, uneven.

At present, Fuji's ghost tooth grinding wheel can grind out more uniform coffee powder, while producing less fine powder and higher grinding efficiency. But not for espresso extraction.

There are four main factors affecting extraction:

Uniformity: Coarse coffee particles are more easily extracted, while finer particles will be extracted in advance, so the larger the coffee powder, the more turbid and irritating the taste. However, when coffee powder with the same grinding particle size and relatively similar shape is extracted, the taste becomes brighter and stronger, and the performance of flavor characteristics is clearer and more consistent.

Fine powder: Coffee powder close to flour can be easily extracted and even dissolved in water, thus affecting the extraction taste of coffee. The more fines, the easier it is to over-extract coffee and the more bitter it tastes. When making espresso coffee, the fine powder is first washed out by the water flow into the cup. If extracted properly, the dense oil will lift the fine powder, and the fine powder will float on the surface of the oil to form a beautiful "tiger spot". But "tiger spot" doesn't represent how espresso tastes. The production of fine powder can be reduced by selecting a better bean grinder or using a screen. However, if there is no fine powder at all, the brewed coffee will also lack a sense of hierarchy, and the balance can only be practiced, not explained.

Calorific value: any grinder grinding wheel in the grinding process will generate heat, coffee powder heating will accelerate the oxidation process, accelerate the aroma volatilization, resulting in brewed coffee flavor weakened. The calorific value of the cutter head depends on many factors such as the size of the grinding disc, the material, the structure of the cutter, the fineness of the grinding, the speed of the motor, the hardness of the coffee beans and so on. Therefore, at present, large brands of bean grinders are beginning to be equipped with heat dissipation windows, refrigeration fans, metal that is easier to dissipate heat, or motor motors with higher torque and lower speed to drive the cutter head, thus reducing heat generation.

Static electricity: Generally speaking, the finer the grinding, the faster the grinding machine, the stronger the static electricity generated; the internal material is plastic, and the lower powder mouth does not adopt the static electricity reduction design of the grinding machine, the static electricity generated is stronger; the fat rich, the roasting degree of coffee beans are ground, and the static electricity generated is stronger. Italian bean mill in the grinding often appear fine powder into a group, affecting the density of the powder after the cloth, resulting in uneven extraction; and single bean mill powder outlet magnet is through electrostatic adsorption silver skin and fine powder, to help reduce excessive extraction taste and miscellaneous taste.