You’d be amazed how often we get asked whether whisky or other spirits like gin, vodka, and rum contain gluten by our customers. Just to confuse things there are certain brands that advertise themselves as gluten free (though they shouldn’t, as we’ll see), whereas most don’t. 

anCnoc process - fermentation

Washbacks at Knockdhu – these contain gluten – but none of it will be in the finished whisky

Does whisky contain gluten?

The very simple answer is no, almost certainly not. Gluten is a protein produced when processing certain grains which can all be used in the production of whisky: wheat, rye, and barley though not maize (corn). The mashing process of these grains with hot water will produce gluten which will be carried through during fermentation. Beer contains gluten so if you have a gluten intolerance, you should avoid most beers. 

But with spirits there’s an additional stage, distillation. Here all heavy compounds like proteins are removed until you are just left with ethanol and, depending on how the distillation is carried out, certain highly-flavoured compounds called congeners. So in a clear spirit that comes straight off the still there will be no gluten. 

Whisky then goes through an ageing process in oak casks which don’t contain gluten. These casks are usually seasoned with fortified wines such as sherry or Port which don’t contain gluten, or bourbon, which as a whiskey also should not contain gluten. The only potential source of gluten is with beer cask whiskies like Jameson Cask Mates – these may contain tiny amounts of gluten.

Vodka, which can be derived from rye, wheat, or barley, is nearly pure ethanol diluted with water so it doesn’t contain gluten. Gin, usually made from a wheat-based spirit, is flavoured with botanicals none of which, as far as we are aware, contain gluten which would in any case be removed during distillation. Finally, rum is made from sugar cane which does not contain gluten. So unless you’re drinking a beer cask-aged spirit, then your whisky, rum, vodka, or gin should not contain gluten, though there is a tiny possibility that something added post-distillation may contain gluten. If you are really worried then check with the producer.

epic single grains

Wheat is a source of gluten but whisky made from it should not contain gluten

So why don’t they say ‘gluten free’ on the bottle?

Because producers are not allowed to do this. There are UK/EU rules about making claims of this nature, when all/most similar foods possess those characteristics: “Food information shall not be misleading, particularly: by suggesting that the food possesses special characteristics when in fact all similar foods possess such characteristics, in particular by specifically emphasising the presence or absence of certain ingredients and/or nutrients.” As distilled spirits don’t contain gluten as standard, you shouldn’t put ‘gluten free’ on the label. Certain producers have got in trouble for this in the past though some still advertise their products as ‘gluten free.’

If you’re still worried about the possibility of gluten in your drink then we recommend going to the website of Coeliac UK. Coeliac disease is an auto-immune condition which means that your body’s immune system attacks your gut when you consume gluten. It’s extremely unpleasant, not like feeling a little bit bloated after having a pizza. This is what it says about gluten in alcoholic drinks:

Cider, wine, sherry, spirits, port, and liqueurs are gluten free. Even when a cereal that contains gluten is used as an ingredient, all spirits are distilled during the manufacturing process and this process removes any trace of gluten. Therefore, all spirit drinks (including malt whisky which is made from barley) are safe for people with coeliac disease.”