Uncultured buttermilk is the thin, slightly sweet liquid left behind after you churn cream into butter. Unlike the thick, tangy cultured buttermilk sold in stores, this byproduct has a milder flavor and thinner body, which leaves many home cooks unsure what to do with it. The good news: it’s versatile enough for cooking, baking, skincare, and even converting into the cultured version you’re used to buying.
How It Differs From Store-Bought Buttermilk
The buttermilk in your grocery store’s dairy aisle is cultured buttermilk, made by adding live bacterial cultures to regular milk. Those bacteria produce lactic acid, which drops the pH, thickens the milk, and creates that familiar sour tang. It typically has a pH between 4.4 and 4.8.
Uncultured buttermilk skips that fermentation step entirely. Because modern heavy cream is pasteurized before it reaches your kitchen, the liquid that separates when you churn butter doesn’t develop much tang on its own. Historically, cream sat at room temperature long enough for natural bacteria to start fermenting it before churning, so old-fashioned buttermilk had more sourness. What you get today is closer to thin, slightly fatty milk with a faint buttery taste.
This difference matters in recipes. Cultured buttermilk’s acidity reacts with baking soda to create lift in biscuits and pancakes. Uncultured buttermilk won’t do that as reliably, so you’ll want to use it in recipes that don’t depend on that acid-base reaction, or convert it to cultured buttermilk first.
Convert It Into Cultured Buttermilk
The simplest way to get more use from uncultured buttermilk is to culture it yourself. You need a starter containing live bacteria, and the easiest source is a carton of store-bought cultured buttermilk. Mix one tablespoon of store-bought buttermilk into each cup of your uncultured buttermilk, cover it loosely, and leave it at room temperature for 12 to 24 hours. The bacteria will ferment the lactose, thickening the liquid and producing lactic acid.
You can also use freeze-dried buttermilk starter cultures, available online or at homesteading supply shops. Since your buttermilk is already a pasteurized byproduct, there’s no need to preheat it before adding the starter. Once it’s thickened and smells pleasantly tangy, refrigerate it. You now have a product that behaves exactly like the store-bought version in any recipe.
Use It in Baking and Cooking
Even without culturing, uncultured buttermilk works well as a liquid ingredient in many recipes. Think of it as a slightly richer substitute for milk or water. It adds a subtle creaminess and a hint of butter flavor that plain milk can’t match.
- Pancakes and waffles: Swap it in for milk in any batter. You won’t get the same rise from baking soda that cultured buttermilk provides, so use baking powder instead (or a combination) to compensate.
- Mashed potatoes: Use it in place of milk or cream for a lighter texture with a faint buttery note.
- Soups and chowders: Stir it in as a base liquid. It adds body without the heaviness of cream.
- Bread dough: Replace the water or milk in yeast breads. The residual milk fat improves the crumb’s softness.
- Smoothies: Blend it with fruit for a protein-rich drink. One cup of buttermilk delivers a meaningful dose of calcium, riboflavin, potassium, and phosphorus.
For recipes that specifically call for cultured buttermilk and rely on its acidity (like traditional soda bread or Southern-style biscuits), you can approximate the effect by adding a teaspoon of white vinegar or lemon juice per cup of uncultured buttermilk. Let it sit for five minutes before mixing it into your dry ingredients.
Marinate Meat With It
Buttermilk marinades are a staple for fried chicken, and uncultured buttermilk can still play this role. The residual lactic acid, even at lower concentrations than in cultured buttermilk, gently breaks down muscle fibers and softens connective tissue. The milk proteins and fat form a protective coating that helps lock in moisture during frying, grilling, or baking.
For the best tenderizing results, combine your uncultured buttermilk with a splash of something more acidic, like a tablespoon of vinegar or a squeeze of lemon, to bring the pH closer to the 4.4 to 4.8 range where cultured buttermilk sits. Soak chicken pieces for at least four hours, or overnight in the fridge. The mild acidity is forgiving compared to straight vinegar or citrus marinades, which can turn meat rubbery if left too long. Buttermilk keeps things tender without that risk.
Try It on Your Skin
Dairy products have been used for centuries as skin softeners, and buttermilk is one of the oldest examples. The lactic acid naturally present in buttermilk is the same compound used in many commercial exfoliating products. It works as a gentle chemical exfoliant, loosening dead skin cells on the surface and promoting smoother texture over time.
You can use uncultured buttermilk as a simple face wash or add a few cups to a warm bath for an all-over soak. Some people apply it directly to sunburned or irritated skin as a cool compress. The fat content helps moisturize while the mild acid does its exfoliating work. It won’t deliver the same intensity as a lab-formulated lactic acid serum, but it’s a practical way to use up buttermilk you’d otherwise pour down the drain.
Freeze It for Later
If you’ve made a big batch of butter and have more buttermilk than you can use in a week, freeze it. Buttermilk freezes well, though it will separate when it thaws. The milk solids and liquids split apart during freezing, but a few minutes of whisking brings everything back together.
Pour it into ice cube trays or measured portions in freezer bags so you can thaw only what you need. Label each container with the amount. Frozen buttermilk works perfectly in cooked and baked recipes after thawing. It’s less ideal for drinking straight, since the texture won’t be quite as smooth as it was fresh.
Know When to Toss It
Fresh uncultured buttermilk should be refrigerated immediately and used within about a week. Because it lacks the protective acidity of cultured buttermilk, it can spoil faster. Watch for thickening, visible chunks, mold, a strong sour or “off” smell, or any discoloration. If it looks or smells different from when you first strained it off your butter, discard it.