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.
However, the important aspect here is whether, how much, when it was begun and the effects of adding alcohol. What we have covered so far began in the 1940s in Manchuria and quickly spread throughout the industry. Sake production hit its all-time high in the mid-1970s and has been falling since. However, bucking this trend has been the top end of the quality range; this is now known as Special Designation Sake or Tokutei meisho shu (特定名称酒). Special designation sake is defined in such a way to mostly encompass the top quality sakes. As such it forbids additives such as sweeteners and acids and limits the weight of added alcohol to no more than 10% of the total rice used by weight. Special designation sake not prefaced with “Junmai” (meaning pure rice) refers to sake with alcohol added. These include Honjozo, Ginjo and Daiginjo but do not include Junmai, Junmai Ginjo or Junmai Daiginjo.
As mentioned, special designation sake limits added alcohol to 10% of total rice but lacks a single term corresponding to Junmai for those that include alcohol. I will refer to all of these as Honjozo rather than “non-Junmai” or the like.
Anyway, given all of the above, most people think that honjozo is new having been developed no earlier than the 1940s. However, this is not the case. Honjozo, or its equivalent was brewed as far back as the 1600s and maybe earlier. “Domo shuzoki” published in 1685 describes not only how to brew honjozo but how to make the proper shochu to use for the alcohol addition. “Huzo denkiroku,” published in 1771, also describes how adding alcohol improved the sake and made it more stable. The National Research Institute of Brewing (NRIB) has verified and extended this conclusion.
The NRIB has shown that the addition of alcohol can in fact, improve the sake. An addition of alcohol to the moromi just prior to pressing helps by causing additional breakdown of the lees and more excretions by yeast of flavor and aroma compounds in the mash. In addition it reduces good substances like Isoamyl alcohol, amino acids and lactic acid by no more than 10%. Isoamyl acetate and succinic acid are reduce by about 20%. Additionally iron and copper are almost cut in half. Of course these results are for additions that do not exceed 10% by weight and hence do not provide insights into sake with sanzoshu or futsushu addition levels.
So, while some choose to avoid Honjozo in favor of Junmai and feel it is the only “true” sake, you now know that honjozo is also “true” sake.