Did you ever look at a field of rice, and wonder how many bottles of sake could be made from it? Maybe not. Regardless, it is not an easy question to answer, because there are way too many variables in the brewing process that affect yield. One is how much the rice was milled before brewing. Obviously, if you grind away the outer 60 percent of the rice, your yield is much less than if you only grind away 25 percent.
Another variable is how far you let the fermentation proceed. Fermenting until every last starch molecule has dissolved will give you much more sake for the rice than stopping fermentation earlier. But squeezing out every last drop of yield takes a huge toll on quality. Also, whether or not alcohol and/or other flavorings are added, as is the case for cheap sake, can have a great effect. (Yields for cheap sake are double what they are for premium sake.)
With all this compounding error, it is very difficult to say how much sake can be brewed from, say, a ton of rice. Still, it's an interesting question. So let's see . . .