Is Sake Always Gluten-Free?

Sadly, there are lots of ways gluten can sneak into your sake

Is sake gluten-free? It's complicated. Jeffrey Coolidge/The Image Bank/Getty Images

Sake is a traditional Japanese alcoholic beverage that you probably know is brewed from fermented rice. Therefore, your instinctive answer to the question "Is sake gluten-free?" probably went something like, "Of course sake is gluten-free. It's made from rice!"

But as is common elsewhere in the gluten-free world, gluten can sneak into sake in various ways. Read on to learn how, and where you might find safe sake.

What Exactly Goes Into Sake?

The best traditional sake is made from three ingredients: rice, purified water and a form of mold called koji. When the three are blended, the koji ferments the rice, resulting in the alcohol-containing rice wine we know as sake.

Obviously, plain rice is gluten-free, as is purified water (we certainly hope!). So where does the first potential gluten issue arise in sake? It's in the koji mold.

Koji (usually the fungus Aspergillus oryzae) can be grown at home or commercially on a variety of substances, including rice and barley. Barley, in fact, is said to make a particularly good substrate for growing koji.

The barley wouldn't be added directly to the rice in the fermentation process, but it's possible that a very minute amount would stick with the koji following the koji growth stage and would, therefore, make it into the mixture to be fermented. This is a similar problem to one that occurs in other products, notably Rice Dream rice-based milk.

So Does That Mean Sake Isn't Safe?

Not necessarily. It's important to note that not every sake manufacturer uses gluten-containing ingredients to make the koji that goes into sake.

It's also important to note that any gluten grains added would amount to a very small percentage of the final product — likely the sake would fall below the U.S. and international legal "gluten-free" standard of less than 20 parts per million, even if the koji fungus was grown on pure barley.

However, many of us react to far less gluten than is legally allowed in "gluten-free"-labeled foods. (Learn more on this: How Much Gluten Can Make Me Sick?)

For example, some of us have trouble with mushrooms, which are frequently grown on gluten grains, while lots of people find that soy is cross-contaminated with too much gluten for them.

There's actually a good parallel between sake and blue cheese when it comes to gluten: the mold used to create blue cheese often is grown on gluten grains, and some people with celiac disease or non-celiac gluten sensitivity react to blue cheese for that reason (read more on gluten and cheese here: Is Cheese Always Gluten-Free?).

More Potential Problems with Sake

I've seen home sake brewing instructions that call for a small amount of toasted wheat flour to be used in the mixture that's added to the rice for fermentation, but it's not clear whether any commercial sake brewing operations would add wheat flour to their mixtures.

More problematically, some sake brands can include a small amount of grain-based distilled alcohol, which may bother those of us who react to gluten-grain-derived alcoholic beverages (learn more here: Is Distilled Alcohol Really Gluten-Free?


To avoid distilled alcohol in sake, choose only sake that's labeled junmai or junmai-shu — this is considered pure sake, with nothing but rice added to the fermentation mixture and no added alcohol. Other forms of sake include honjozo-shu (includes a small amount of distilled alcohol), and ginjo-shu and daiginjo-shu (both of which may or may not contain distilled alcohol.

Okay, Can I Drink Sake or Not?

If you're not particularly sensitive to trace gluten and you don't react to alcohol distilled from gluten grains, you probably won't have a problem with any sake on the market.

However, if you react to things like mushrooms and edamame, you should steer clear if sake unless you can find a manufacturer that doesn't use barley at all as part of the brewing process. And if you react to gluten grain-derived alcohol, look for a sake labeled junmai or junmai-shu.

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