While most of us who have paid attention to honjozo have heard about how the rice shortage around World War II sparked the need to stretch rice farther. For sake, this need was addressed with the addition of alcohol to produce more sake for the given amount of rice used. The most common sake in Japan, Sanzoshu (三増酒) and to a lesser extent Futsushu (普通酒), retain their use of high addition levels of alcohol. San (三) means three so Sanzoshu is triple sake. It has this name because enough alcohol is added when making Sanzoshu to triple the resultant quantity of sake. When tripling the output in this way other factors are thrown out of balance. To correct this, acids (酸類) and sweeteners (糖類) are added to sanzoshu to make it taste more like sake that has not been diluted so much.
Futsu (普通), means ordinary or standard. Despite this name, futsushu actually has a lower yearly production level than sanzoshu. And, while futsushu is not allowed to add sweeteners nor as much alcohol as is allowed for sanzoshu it is not as restrictive as special designation sakes like honjozo (本醸造). In addition to higher levels of alcohol, futsushu, as with sanzoshu, is allowed to add acids to the sake that are not allowed in the special designated class.