Currently using an antique hand grinder for coffee beans and would like to know what fine coffee is supposed to look and feel like to see if the antique grinder is up to snuff
You can try using this tool by Unspecialty to get an idea of the grind size/uniformity without buying any fancy equipment. As far as whether your grinder is up to snuff, I think how the coffee tastes to you is the best determinant. If it tastes good to you, it’s good coffee :)
I can tell you with certainty that grind uniformity is also very important and that’s probably what you’re gonna lack the most.
There are specialized sifters to identify how many microns large the coffee is.
I don’t think most antique grinders will grind well, you need ok burrs and somewhat tight tolerances. Do you have a photo of your machine?
It depends on the brew method: finer for espresso, medium for drip or pour-over, and coarse for French press. Sometimes I grind my coffee a bit finer for a different taste.
Fineness aside, the main quality you want in your ground coffee is a very even size distribution around your desired size. If a lot of the resulting grinds are smaller or larger, especially very fine dust, the resulting brew will be much less balanced. If you want to, you can buy a sifter set to sort out different particle sizes. If you really want to, there’s software to do optical size distribution analysis.