Why Oat Milk Isn't Always Gluten-Free (And How To Ensure It Is)

Oat milk has exploded in popularity recently, with coffee chains like Starbucks releasing new drinks with the non-dairy alternative actually in their names and sales in grocery stores rocketing upward. Yet if you eat a gluten-free diet or have celiac disease, you know you have to be extra-careful about what you consume — and store-bought oat milk is no exception. While this plant-based alternative is, in its purest form, gluten-free, there may be cross-contamination because of how (or, rather, where) oats are grown and processed.

Oats may be grown near wheat-containing crops or manufactured for milk in the same spaces where wheat-containing ingredients are also being processed. Since this is the case, gluten-free folks cannot drink oat milk unless a label specifies that the beverage is gluten-free and wheat is not a declared allergen listed with the ingredients.

That said, some major brand name oat milks are gluten-free, such as the ever-popular Oatly and Planet Oat. However, the Aldi store brand Friendly Farms offers an oat milk that does not claim to be gluten-free anywhere on its packaging, and indeed, if you read the ingredients, the label declares that the milk may contain wheat. To confuse matters, some of Califia Farms' oat milks are gluten-free, like its Extra Creamy Oatmilk, while others, like the brand's Organic Oatmilk, are not.

You have another option beyond reading labels to ensure that your oat milk is gluten-free — and that's to make homemade oat milk. It's super easy to do and only requires two ingredients: gluten-free old-fashioned rolled oats and water. (You can obviously add sweeteners and a pinch of salt, but let's keep things simple.) You'll start by soaking and rinsing your oats and then blending them with water.

To get the milk as smooth as possible, you will want to filter it next. You can use a fine-mesh sieve, cheesecloth, or a nut-milk bag — or a combination of the three. It still may not be as smooth as store-bought, which is why you might think twice before making oat milk at home. That said, if you want to be perfectly sure that your oat milk is gluten-free and you like the added bonuses of knowing exactly what's in it and customizing it to your tastes, it could be worth the effort.

Now, to order coffee and lattes with more peace of mind, check out the brand of oat milk that Starbucks uses.