Three types of home country grainmill
Stone Mills - These grain mills have the ability to grind fine flours and can be adjusted for a range of flours from fine to cracked grain consistency. Cracked is perfect for part of the brewing beer process. The more oily grains and beans should not be used as they will cause the stones to glaze. The stones will need cleaning to remove fine particles that lodge within the stones. Stones wear out over time and need replacing, depending on how often you use your home grain mill.
SteelCone Burr Mills - These home grain mills use a stainless steel milling head. They too can mill grains into a range of from fine to cracked grain consistency, however they may not be able to mill as fine as a stone mill is capable. You can mill a wider variety of grains and beans than a stone mill without fear of messing up the milling heads, they are easy to clean. Generally the steel-cone burr mill will produce flour at a slower speed, and as a bonus, operate more quietly than other home grain mills. Also, a slower speed will mean less heat will be created and less loss of nutriments. Steel cone burrs will mill most whole grains and beans, but corn and beans will need to be cracked. Then run through again on a finer setting if you want bean or corn flours. For the most part the fine flour produced is suitable for breads, muffins, pastries, etc, but the flour will not be as fine as you may desire.
Micronizing Grain Mills- These are considered the "newer technology" grain milling machine. A micronizer is made up of concentric circles of stainless steel "teeth" which spin at a very high speed. They "burst" the grain into flour when the grain comes in contact with the stainless steel milling head. The result is beautiful flours in a fraction of time, the result is also low-temperature milling. These mills will produce the finest flours and will adjust to as coarse as corn meal. Since micronizers run at very high speeds they produce flour more quickly than a steel-cone burr or stone home grain mills, but they generate a lot of noise. These are also the most popular type of grain mill on the market.
When purchasing a home grain mill, take a VERY deep breath and relax. Mills can be expensive for electric or less for hand cranked grain mills. Investing in a kitchen appliance like a home grain mill is just that, an investment. If you do your research right the mill will be with you and tour family for years. And all of those years will be rewarded with great healthy food preparation and healthy food products.