An ideal coffee grinder produces ground particles that are uniform and correct in size. By this we mean that the size of the ground coffee particles should correspond to the grinder setting, whether fine or not. The size of the coffee grounds produced should also be appropriate for the intended brewing method, as described in the product manual.
To test each grinder for our coffee grinder reviews, we first hand wash and dry all parts recommended by the manufacturer. We then set each machine to the appropriate level for grinding filter coffee or automatic coffee makers (again, as directed in the manual). Sometimes the manual lacks specific instructions. In this case, we select the medium coarse setting to grind the coffee and then increase the grinding level by another coarse level (from fine grinding, such as espresso grinding, to coarse grinding). For example, if a grinder has a total of 16 coarse grind settings (assuming 16 is the coarsest grind option and 1 is fine), we set it to coarse setting 9.
Check this out: Five things you should know before buying a coffee grinder
Next, we weigh out 10 grams of whole coffee beans to grind. By default these are our test beans Colombian Kirkland Roast. They are the same beans that we use for our coffee machine tests. (No judgments please.) When you grind as much coffee and espresso as we do, it pays to be frugal.
We then run our sample beans through the mill. We also note how long the grinder takes to grind the coffee beans. Next, we carefully collect the sediment and then sieve it with a double sieve for 60 seconds. That’s what we use Kruve sieve system. Our original Kruve Two device was equipped with two mesh screens with different opening sizes (800 and 400 microns). This step allows us to measure the grind size and grind consistency of our sample. The Screw base has now replaced the Kruve Two and offers five mesh screens (300, 500, 800, 1,100 and 1,400 microns).
We used a Kruve coffee strainer system to check the consistency of the grind.
A high-quality electric coffee grinder or hand grinder produces ground coffee, preferably with stainless steel blades, whose particle size is usually between 400 and 800 micrometers (at the grinding settings we choose). Finally, we weigh the coffee grounds that collect between the two sieves (800 microns at the top, 400 microns at the bottom).
A bad grinder grinds particles of different sizes, from large to small. Knife sharpeners are notorious for this problem. In contrast to a coffee grinder with blades, a coffee grinder with a steel or ceramic grinder typically produces a grind that is much more evenly ground.
Additionally, we grind at least twice more. From there we can record an average optimal yield for each mill.
