Sake requires steamed rice, it doesn't touch the water when cooking.
We have one of those big seafood steamers. Two parts of porcelain covered steel, the bottom part has a spigot on it. The top part has holes in its bottom for allowing the steam up into the top. Probably have to heat up a gallon of water and the rice needs to steam for one hour. Heats up the house a lot, good for a really cold day.
I should remember to shoot the photos from a lower elevation ;-)
I read someone was experimenting with a pressure cooker. We have this little six quart cooker from TFAL and it has a nice stainless steel steaming basket perfect for the rice.
Only two cups of water and twenty minutes cook time after it comes up to pressure. A major savings in time and energy.
The big bonus, it made the best Kome Koji so far.