Many friends who prefer fine coffee always focus their attention on extraction equipment when buying equipment, whether it is hand brewing, French press, electric drip filter, siphon pot, or even espresso machine, people always discuss their professional degree when buying.
But the performance and professionalism of the grinder are the objects of serious neglect, and there is a definition in the coffee industry: the grinder is more important than the espresso machine. Pro coffee shops pay so much attention, if you want to make a qualified cup of fine coffee at home, a coffee grinder is enough to attract everyone's attention. Come and get to know the bean grinder.
Bean grinders can generally be divided into two main types: blade grinders and burr grinders.
●Blades are used to grind coffee into granules by chipping, so the granules are mainly flaky in shape.
●Burr is used to grinding coffee into particles by grinding, so the granules are mainly in the form of blocks.
Let's continue to learn what is a blade grinder and what is a burr grinder.
What is a Blade Coffee Grinder?
Features and movement of the blade-type grinder:
The operating principle of the blade-type grinder is composed of two blades on the top and bottom, the base is fixed on the motor, and when the motor starts, rotating the top and bottom blades produce cutting action.
When the coffee particles fall from the middle, the bottom rotating knife disc will spin the coffee beans to the periphery, pushing the coffee beans into the tooth knife part for grinding.
The cutter is placed in parallel, so the coffee beans need to rely on the force of the bottom cutter rotation to push the coffee beans into the cutter, thus the weight of the coffee beans placed on top will affect the uniformity of the coffee beans into the cutter, which in turn affects the uniformity of the grind.
Moreover, the number of collisions between coffee beans increases due to pushing and squeezing, resulting in a higher percentage of fine powder production. This is the reason why the common blade grinder grinds slightly fewer uniform particles and more fine powder.
What is a Burr Coffee Grinder?
Characteristics and movement of burr grinding:
A Burr grinder is placed at the bottom of the conical knife disc, and then the outer ring knife disc to grind, coffee beans from above after the fall, will be with the conical knife disc rotation will be pulled down coffee beans, and then produce grinding action.
So the particles can not rely on pushing the coffee out, and blade grinder comparison, the number of collisions between the particles will be reduced, so the proportion of burrs to produce fine powder will be much less than the blade grinder and coffee grinding uniformity will be greatly enhanced.
What is the Difference?
A good bean grinder has to meet these two conditions: first, less fine powder; second, the finished ground particles should not have different sizes under the naked eye's observation.
Fine powder will absorb water faster than normal particles, so in the same brewing bad, it will release a bad taste earlier and make the coffee full of a bad bitter overflow taste.
So what are the differences between these two types of grinders?
Advantages of Each
Ground coffee powder coffee-making efficiency is relatively high and more suitable for fast-paced store use.
Home models of bean grinders using blade type are also common and are now the most common type of blade on the market. The most suitable for grinding espresso coffee powder.
Ground coffee powder is granular, and less prone to odor and astringency, and brewed coffee has a hierarchy of flavors, and the grinding method reduces the collision between coffee beans, and the fine powder rate is lower, which is generally more suitable for making hand-brewed coffee and siphon pots.
Disadvantages of Each
Grind particles slightly less uniform, more fine powder, because the flat knife grinder blade to coffee beans for random cutting, in the brewing easily lead to under-extraction or over-extraction of coffee powder, in addition to the flat knife friction will generate heat, especially in the blade grinder work for a long time, there will be obvious burning and bitter taste.
The grinding particles are large and thick, and the coffee particles have a smaller area to absorb water, so the time it takes for the coffee particles to absorb the water to saturation will be a little longer than the blades.
By understanding the basic working principle of blades and burrs, we can conclude that:
1. the particles produced by the blade are mainly in the form of flakes, while the particles of the burr grinder are mainly in the form of blocks.
2. The flake particles of the blade have a larger area, so the area inside the particles in contact with water will also be more.
3. The flake coffee powder has a large contact area with water, so the proportion of soluble substances released will also become more when it comes in contact with hot water at the beginning.
4. Granular coffee powder has a smaller area, and the area where the cell walls can come into contact with water will also be small. Therefore, the hot water contact area is small, so the concentration of coffee will also become relatively small.
In other words, when using a blade grinder, avoid over-extraction. And when using a burr grinder, avoid under-extraction.
Depending on the coffee flavor, we can summarize as follows.
For coffee that needs to be concentrated, use a blade grinder the grinder, the high concentration will make the aroma more pronounced.
For coffee that needs low concentration, choose a burr grinder on the grinder, the low concentration will make the coffee's bitterness and unpleasant taste also relatively reduced a lot.