Link:History of stone-mills in Japan:Buddism in Japan

What is tofu, You can find an information on the site :

Making tofu is a powder process which processing powder in water. The process starts raw tofu grade soy beans. The beans are soaked in water overnight then drained. The beans are then pulverized with stone mill or proper grinding machine.

The beans change to slurry, which is powder in water.@For the taste, most important factor is the pulverizing process. The tofu produced by stone-mill are competing with the mass produced tofu, because products by mass production does not taste good.

Now, many shops in Japan have produce by high speed grinder against slow speed stone mill grinding. The reason is productivity for mass production. Recently, some shops have a prejudice against stone mill grinding. That is of the latest fashion. The start of the fashion was ,summer of 1995,the appearance of 10 dollars for a piece tofu in SINJUKU,Tokyo, where about 10 dollars for a piece of tofu against cheaper than one dollar. The catch-phrase is stone-mill tofu. The fashion spread all over the Japan.