The Ultimate Guide To Buttermilk And Buttermilk Substitutes

There’s something about buttermilk’s pleasant tang that perfectly rounds out both the sweetness in recipes like carrot cake muffins and the savouriness of things like buttermilk-cornbread waffles. Because buttermilk delivers extra-delicious results, it’s been a key ingredient in many all-time favourite dishes, from decadent Grand Marnier Chocolate cake to crispy fried chicken.

But what makes buttermilk so different from other dairy products on the market? Here’s a quick rundown of everything you need to know about buttermilk and the best buttermilk substitutes.

What is buttermilk vs regular milk?

Originally, buttermilk was the liquid left over when milk was churned into butter. (Get it?) In the days before refrigeration, naturally occurring bacteria in the milk would ferment, giving rise to buttermilk's distinctive tang.

Dr. Yvonne Yuan, president of the Canadian Institute of Food Science and Technology and associate professor at Toronto Metropolitan University’s School of Nutrition, says that buttermilk is produced differently now. “Most commercial buttermilk products are created by introducing bacterial cultures to fresh, pasteurized milk," she explains, "resulting in its thickened consistency and tart flavours.”

What does buttermilk do for baking?

Buttermilk’s purpose—be it for baking or cooking—is threefold: Leavening, flavour, and texture. From a baking perspective, Shannon Nocos, pastry chef and owner of Toronto-based Kwento bakery, says that buttermilk adds that extra oomph to chocolate-based cakes.

“Buttermilk complements the acidity of cocoa and adds a level of richness and depth to the flavour,” she says. “But generally, if you have baking soda, you need something with acidity to activate it and get it to rise, which is where buttermilk might come in.”

When mixed with baking soda, buttermilk's acid initiates a reaction that helps baked goods rise.

It also imparts that signature tang to classics like buttermilk pancakes and flaky buttermilk biscuits. Beyond leavening, buttermilk's acidity contributes to the moist tenderness of pastries, producing ultra-moist muffins and cakes. (When it comes to cooking, the acids in buttermilk break down the proteins of meats, which makes it a popular choice for tenderizing marinades and sauces.)

How does buttermilk differ from regular milk?

Like regular or whole milk, buttermilk can be a source of essential nutrients like calcium, protein and vitamins A, B12, and B6—just to name a few. But unlike milk, buttermilk can be easier to digest for those with lactose intolerance. According to Yuan, this is all thanks to the bacteria added to buttermilk. “If you compare the two products, the protein is very similar. The carbohydrate–mostly sugars or the lactose that is naturally present in milk—is different because fermentation converts it to lactic acid.”

Buttermilk, however, may contain higher levels of sodium compared to regular milk because salt helps control the growth of the bacteria during the fermentation stage in buttermilk production. Yuan suggests checking the nutritional information of buttermilk products if you’re on a low-sodium diet.

The best buttermilk substitutes

1. One tbsp of vinegar (or lemon juice) added to 1 cup of milk (or cream)

Chef Nocos notes that adding some sort of acid to milk or cream is a good, cost-effective buttermilk substitute. “We've used white vinegar, apple cider vinegar and lemon juice.”

Cream–light cream, table cream, half & half—has a higher fat content than milk, which means it has a thicker consistency and will add an extra richness to recipes.

2. Yogurt diluted with milk

Dr. Yuan suggests that yogurt, which has a similar taste and fermentation process, is another substitute to consider if a recipe calls for buttermilk. “Buttermilk, as its name would indicate, is generally quite fluid,” she says, “so you could use yogurt but dilute it to make it more liquid.”

Not all yogurts are created equal, however. Drinkable yogurts can be substituted for buttermilk in a 1-to-1 ration, but thicker yogurts will require some eyeballing. Thick yogurts like Greek or pressed yogurt can be diluted with between one-quarter to one-third their volume with milk or water to get that buttermilk consistency you’re looking for.

3. Diluted sour cream

True to its name, sour cream is the sourest and tangiest product in the dairy aisle. But like yogurt, sour cream has a thicker consistency which can be diluted with a bit of water or milk to reach the consistency of buttermilk. If you don’t mind a denser cake or muffin batter, use 3/4 cup of sour cream for every cup of buttermilk you need.

4. Milk and cream of tartar

Cream of tartar is the acidic byproduct of winemaking typically used to stabilize meringues. It’s also a versatile baking staple to use in place of vinegar or citrus juice. Mix 1 and 3/4 teaspoons of cream of tartar to a cup of milk.

5. Buttermilk powder

Buttermilk powder is a great way to ensure you always have buttermilk on hand. Shelf-stable and available at many bulk stores (I buy mine at the Bulk Barn), buttermilk powder gives you the same results and more space to experiment. Try mixing 2 tbsp of powder to a cup of water (note: the precise ratio varies depending on the brand) for chocolate cakes and red velvet cakes, and adding 1 tbsp of buttermilk powder to give cookies and dinner rolls a flavour boost.

How to store buttermilk

The fridge

Keep buttermilk in the fridge. Always check if the carton's plastic cap is tightly closed to prevent moisture and other food odours from affecting its quality. If your buttermilk carton doesn't have a resealable cap, seal it with a food clip, then wrap the top half with plastic wrap (or any of these eco-friendly alternatives). Alternatively, you can transfer the buttermilk into a clean mason jar or glass bottle.

The freezer

Freeze leftover buttermilk in ice cube trays or a freezer-safe container. It can be stored for 3 to 4 months. Thaw in the refrigerator when needed. The liquid can turn grainy once thawed, but it’s nothing a little vigorous whisking can’t solve.

How can I tell if my buttermilk has gone bad?

It it smells or tastes weird, it's off. Buttermilk  should have a mildly tangy aroma and taste; if it smells rancid or a lot more sour than when you first opened the carton, don't use it.

How to Store buttermilk powder

Unopened buttermilk powder can be stored at room temperature in your pantry, away from direct sunlight. Once opened, it needs to be kept in an air-tight container to prevent clumping and spoilage. Store in a cool dry place or in the fridge.