Sato is a home made rice wine, made from fermenting sticky rice with water and yeast. You will need the dried yeast culture to make this. It's much more like a beer than a wine, and it need not be alcoholic, you can make a sweet Sato by fermenting for only a short period of time.
The golden rule is cleanliness! Any mould contamination will ruin the Sato, so you must clean everything in hot water and clean your hands carefully. The water should also be boiled and then cooled to make it sterile. If your water is chlorinated it can affect the yeast, so leave the water to stand for the chlorine to escape before using it.When in Thailand, try the commercially made Sato, or one of the commercial Thai Beers. The commercial Sato below is Chaopraya, which is one of the better ones.