How we tested
Twenty years ago, dairy-free milks were relegated to natural foods stores, but today they’re mainstream. Oat milk is one of the fastest growing nondairy milks, according to data from SPINS, a wellness-focused market research company. Its popularity is due to several factors. First, it has a naturally sweet and nutty flavor. Second, it’s a welcome alternative to other dairy-free milks for people with tree nut or soy allergies. Finally, it makes less of an environmental impact to produce than many other milks, and it requires significantly less water to produce than cow’s milk and almond milk do, according to BBC News.
Oat milks come in different styles: original, extra-creamy, low-fat, unsweetened, and "barista" blends intended for whipping into foam for lattes or cappuccinos. We chose six nationally available brands of oat milk, narrowing down the lineup to original styles that don't list sugar as an ingredient (but that doesn't mean they're sugar-free—more on that later). We tasted the mix of refrigerated and shelf-stable products plain and then in coffee.
How Is Oat Milk Made?
Oat milk is simple to make at home—just process a mixture of oats, water, and salt in a blender and strain it. However, homemade oat milk lasts for only several days in the refrigerator, and consumers appreciate the convenience of buying commercially made oat milks. The process of making oat milk on an industrial scale is more complicated, and most of the company representatives we spoke with declined to reveal the specifics of their processes. But by examining the labels of the products we tasted, we were able to draw some conclusions about general similarities across brands. Enzymes are typically added to the oat-water mixture to break down some of the oats' starch into sugar, and the mixture is usually strained to remove oat bran and other oat solids. Many manufacturers also add nutrients such as calcium and vitamins A, D, and B12 to mimic the vitamins found in or added to cow’s milk; salt is also added. Some manufacturers add gums, oils, and emulsifiers to give the milks body, make them smooth, and prevent separation. All the manufacturers use ultra-high temperature (UHT) processing to pasteurize their oat milks; this process heats the milks to 280 degrees for just a few seconds to kill off potentially harmful bacteria.
For Smooth Oat Milk: Include Additives and Remove Oat Bran
Some of the oat milks we tasted were thin (think skim milk), while others were more viscous (think whole milk). We had a slight preference for the thicker oat milks; additives such as oil and phosphates and thickening agents such as gellan gum gave them both body and richness. Some of these additives also ensured that the milks stayed smooth and fully incorporated once packaged.
The oat milks with fewer additives—or none at all—were thinner and “chalky,” as if they contained sediment or grit. The inclusion of oat bran also made for gritty oat milk. Most manufacturers remove it during production, but one added it back to give their milk extra fiber.
Uncovering Flavor Differences
Many tasters liked the slight nuttiness and mild sweetness of oat milk, but some of the products we tasted were more oat forward than others. The amount of oat flavor present in each milk is most likely influenced by the type of oats used to make it and how the oats were processed. Some of the products were sweeter than others. The amount of sugar per serving and whether or not the product was shelf-stable both played a role in determining flavor.
Even though none of the oat milks we chose list sugar as an ingredient, the range of sugar per serving varied widely—anywhere from 1 gram to a whopping 17 grams per cup. Samples that contained 4 to 7 grams of sugar were described as being “pleasantly sweet,” while the product with 17 grams of sugar per serving had an “overpowering sweetness [that was] a deal breaker.” The wide range of sugar levels is due to manufacturing differences. Enzymes are more active at certain temperatures, so the oat milks that contained more sugar per serving were likely cooked longer and/or remained in a more enzyme-active temperature range for longer. Additionally, the type and amount of enzyme used determines how much sugar is created.
The two shelf-stable oat milks tasted “sour.” Although all the oat milks in our lineup underwent UHT pasteurization, the shelf-stable products were likely heated for longer. A difference of just a few seconds is enough to cause the chemical reactions and the breakdown of protein that can alter the flavor of the oat milk. To really zero in on the flavor differences between shelf-stable and refrigerated oat milks, we purchased the shelf-stable version of the refrigerated Oatly product in our lineup. (Oatly is the only brand in our lineup that offers both shelf-stable and refrigerated options.) The shelf-stable Oatly milk tasted sour, while the refrigerated version tasted bright and pleasant. A representative for Oatly confirmed the “process for [its] ambient oatmilks does involve higher temperatures and time to meet FDA requirements for shelf-stable products.” Our conclusion: When choosing an oat milk, skip the shelf-stable products and head to the dairy case.
One Final Tasting: Can You Bake with Oat Milk?
After our initial tastings, we conducted another test to see how oat milk would perform when substituted for coconut milk in our Vegan Savory Drop Biscuits recipe. We chose two products: our winner, which had a fairly neutral and mild flavor, and one of our recommended oat milks, which had a bold oat flavor. Our mild-tasting winner gave us tender biscuits that were subtly sweet; the biscuits made with the bolder product tasted overwhelmingly like oats. When baking or cooking we suggest choosing a mild- or neutral-tasting oat milk that won’t interfere with or dominate the other ingredients.
Our Favorite Oat Milk: Chobani Oat Plain
We can fully recommend three of the oat milks we tasted, but Chobani Oat Plain came out on top. It had a “mellow oat flavor” and was silky, homogenized, and moderately thick. The addition of oil, gum, and emulsifiers made it "supersmooth." With 7 grams of sugar per serving, it was just sweet enough. If you're looking for a great nondairy milk for drinking plain, adding to coffee or tea, or baking, we think Chobani Oat Plain is an excellent choice.
- Taste six products, priced from about $0.05 to about $0.30 per ounce, selected from best-selling, nationally available brands and purchased in Boston-area supermarkets
- Taste plain
- Taste in coffee
- Samples were randomized and tasted blind to eliminate bias
- Sugar amounts are based on a 1-cup serving size
- With the top-rated milk and the milk with the boldest oat flavor: Bake Vegan Savory Drop Biscuits