What shochu is

Japanese law divides shochu in two, and the division is about the still rather than the ingredient. It is the single most useful thing to understand about the category, because the two halves are barely the same drink.

Korui shochu is distilled in a continuous column still, which strips out congeners and produces something close to neutral. The law caps it below 36 percent alcohol. It is made industrially, it is cheap, it is not tied to any region, and it is the base of most canned chuhai and most izakaya highballs in Japan. Nothing is wrong with it; it is simply designed to taste of very little so that whatever you mix into it can taste of something.

Honkaku shochu is the other half, and it is a subset of the single-distilled class the law calls tanshiki joryu shochu, capped at 45 percent. Single distillation in a pot still, koji made from grain or potato, and a defined list of permitted base ingredients. No added sugar, no flavouring, nothing but water added after the still. The word honkaku, meaning authentic or genuine, was given a formal definition on 1 November 2002 to stop it being used loosely.

In practice: if a bottle names its raw material and its distillery, it is honkaku. If it comes in a plastic jug and names neither, it is korui. Both are on this site, and the tool will tell you which you are holding.

Three koji moulds are used in Japan, they are commonly called yellow, white and black, and the difference between them is not decoration. It is acid.

Black koji is Aspergillus luchuensis. White koji is Aspergillus luchuensis mut. kawachii, an albino mutant of the black one discovered in the early twentieth century, which is why the two behave so similarly. Both throw off large amounts of citric acid, which drops the pH of the fermenting mash far enough that spoilage organisms cannot take hold.

That is the whole reason shochu is a southern drink. Kyushu and Okinawa are hot, fermentation in a warm room is a race between your yeast and everything else in the air, and a mould that acidifies its own mash wins that race. Yellow koji, Aspergillus oryzae, the mould used for sake and soy sauce, produces very little citric acid and was historically unreliable this far south.

What you taste: black koji tends to give a heavier, richer, more savoury spirit with a sharper finish; white gives a cleaner, softer, sweeter one. Yellow koji, now usable year-round because refrigeration solved the problem it could not solve for itself, gives something fruity and closer to ginjo sake. Nishi Shuzo built a whole reputation on that last discovery: their Tomino Hozan is a yellow koji sweet potato shochu, and it overturned the assumption that imo shochu had to smell of the field.

Awamori sits inside the same legal class as honkaku shochu, and it is a different drink with an older history. It has been made in Okinawa since roughly the fifteenth century, when distilling reached the Ryukyu kingdom through its trade with Siam. Mainland shochu most likely descends from it rather than the other way round.

Three things make it distinct, and all three are requirements rather than habits. It uses long-grain Thai indica rice, not Japanese short-grain. It uses black koji, always. And it is made by the all-koji method, zen koji shikomi, in which the entire mash is koji.

That last point is the one worth slowing down on. A shochu mash is built in two stages: a first mash of koji and yeast, then a second in which the bulk raw material, the potato or the barley, is added to the working ferment. Awamori has no second stage. Everything is koji rice, fermented in one go. It is why awamori is denser, more savoury, and why it ages so well.

Awamori aged three years or more is kusu. The traditional method is shitsugi, topping up older clay pots from younger ones down a chain, which is the same principle as a sherry solera.

Japan protects five shochu and awamori origin names as geographical indications under the Liquor Tax Act, administered by the National Tax Agency. These are not marketing terms. A producer outside the named area may not use the name, however similar their spirit is, and each name carries a production rule stricter than the shochu definition itself.

Iki, Kuma and Ryukyu were designated in 1995 and are among the small number of Japanese products recognised under the WTO TRIPS agreement. Satsuma followed in 2005. Tokyo Shimazake was designated in March 2024, the first new one in eighteen years, and it is the one most English-language writing on shochu has not caught up with yet.

They are different drinks, and the confusion is mostly an American licensing artefact rather than a genuine ambiguity.

Korean soju is defined by its strength and method rather than its ingredient. Under South Korea's liquor tax law, soju is a distilled spirit below 38 percent. The overwhelming majority of what is sold is made by diluting highly rectified ethanol, distilled from tapioca, corn or molasses in a column still, then sweetened and flavoured. Traditional soju uses nuruk, a wild-inoculated cake of ground grain, rather than koji cultivated from a single strain.

Honkaku shochu cannot be made that way. It is single-distilled in a pot still from a defined list of raw materials, with koji, and nothing but water may be added afterwards.

Now the licensing part, which is why this matters if you are holding a bottle. In many US states a beer and wine licence cannot sell spirits. Since the 1990s an exception has existed for soju at or below 24 percent, and because there was no equivalent exception for shochu, Japanese shochu that wanted to be sold by restaurants with beer and wine licences was labelled soju. Thousands of bottles of Japanese shochu were sold in America under the name of a Korean spirit, for a reason that had nothing to do with what was inside them.

That has now been fixed in the two states that matter most. New York amended its law in July 2022, and California passed AB 416 in October 2023, both allowing shochu at or below 24 percent to be sold under a beer and wine licence and under its own name. Bottles printed before those dates are still in circulation, so a bottle in your hand labelled soju may well be shochu.