Does the grinding speed affact coffee powder quality?
Updated: Jan 10
It's really a question haunting many coffee enthusiasts for a long time. Because when we make our own grinds, we begin to wonder how to make the daily coffee better. Every sip of coffee is determined by many factors. For example, the coffee bean quality, the grinder performance, the fineness and consistency of the grind, the coffee maker quality, the brewing method, the brewing operation, etc.
As a coffee lover, don't blame these people. Because they are the one just want perfection. So as a direct supplier of coffee grinder, I will share our knowledge about this question this time.
First, Let's analyze them by grinder categories:
For the manual coffee grinder, the rotation speed varies according to different persons. But the range of speed can hardly exceed 200r/min which is still low speed. So, in fact, there's no need to worry about the heat problem. Because the heat generated by friction is a very small part that won't affect the flavor even a bit.
So the rotating speed doesn't have any influence on the quality of the powder for manual grinders. If we grind slow or fast, it doesn't matter.
About the electrical grinder, they are all equipped with a motor inside which can supply very strong power and high speed. Here we will check three kinds of coffee grinders that different in burr shapes.
And the speed for all electrical grinder is unchangeable. So we have to change the motor manually to change the speed. The speed will change the speed in a range because the structure of the machine can only contain certain motors. Too big motors won't fit in and too small motors won't be fixed.
Attention: Never imitate at home, we are professional, so we can do the experiment.
Blade grinder uses high speed rotating propeller-shaped blade to cut the beans. When working, the beans will strike the container and the blade many many times to realize the cutting function. So in this process, a lot of heat will be generated. And the more time it grinds for, the more heat it releases.
Some think that too much heat will affect the flavor of the coffee. But for me, I really didn't taste the obvious difference until now. Some think the heat will make a difference for the coffee. So I will still show the heat in my experience report.
When we put in a smaller motor, speed is slower and the cutting is not satisfactory. We can't even get the so-called coffee powder. So coffee brewing is not possible.
When we use a bigger motor, speed is higher and performance is better. But the motor over-heat too quickly, we have to stop for a while before next grinding. The heat generated in the coffee increase absolutely. And the fineness of grinds can improve a bit but not too much.
(2)Conical burr grinder
A conical grinder normally has a comparatively medium speed. The burr is made of an inner conical burr and an outer hollow cylindrical burr which is fixed. The inner burr is connected to a motor and transfer the rotation to make the grinding. The conical burr normally creates less heat which some lovers prefer.
Equipped with a smaller motor, the grinder will grind slower, but the fineness is the same and not too much heat too. If the motor is too small, the grinder will be stuck in the grinding process.
Equipped with a bigger motor, the grinder grinds faster. With the higher speed, the heat will increase sharply. The fineness is the same, but the beans will start jumping frequently inside the hopper if speed is too high.
(3)Flat burr grinder
The flat burr grinder is similar to the conical grinder. The only difference between them is the burr shape. The flat burr is hollow cylindrical burrs parallel to each other. The grinding speed is already very high for the flat burr grinder. So we can't avoid much heat generated. And for the experiment, We just use the slower motor because we worry if high speed will damage the burrs which will be awful.
Equipped with a smaller motor, The speed will be lower. The production is decreased but fineness is the same. Very good thing is that the heat decreases too. But if the power is too little, the grinder will be stuck which is bad. I think the reason is the decreasing of centrifugal force which works as a puller to collect the beans in the hopper to between the gap of beans.
After these experiments, I think we can make a big conclusion:
Question: Does the grinding speed affect coffee powder quality?
The speed will determine the heat generated by grinding.
The too-low speed will make the grinder stuck or don't work well.
The too-high speed won't increase the fineness of coffee powder but create more heat.