How to Make Sour Milk

The go-to recipe for great-grandmas and brilliant bakers.

Table of Contents

Now, you might be thinking: “Why on earth would anyone want to purposely make their milk sour?” But hear me out. Lots of recipes (especially for baked goods) call for sour milk to enhance the flavor and create a unique texture. For example, you can add it to pancakes instead of buttermilk to fluff them up. Or you could add it to muffins for moisture and flavor. Some people even like sour milk salad dressing, which acts like a creamy and tangy vinaigrette.

So as you can imagine, making your own sour milk can be handy for any of these recipes and more! Especially for bakers who want to make some bold moves, a jar of sour milk in the fridge is a staple. We shouldn’t be afraid of an ingredient just because it says “sour.” After all, we use sour cream, don’t we? Think of it like this: if a recipe needs a little boost, this could very well be the way to do it.

Is Sour Milk Healthy?

With the use of whole milk and fresh lemon juice, you can’t really go wrong. Despite it being “sour,” again, there’s no reason to shy away from it. Since it’s going to be mixed into a recipe and not drunk straight from the cup, there’s no way to “overdo” it here. Unfortunately for my lactose-intolerant or plant-based friends, this recipe can’t be made dairy-free because the lactose in milk is required for the souring process. That being said, dairy-free folk can try using a vegan sour cream instead in their recipes for a similar effect.

How does it Work?

Okay, let’s be chemists for a hot second… When milk is mixed with vinegar or lemon juice, it turns sour within 5-10 minutes. This is because the acids cause the milk protein to coagulate, creating a pungent sour flavor and thicker texture. It is quite similar to sour cream, although it has more liquid. It’s also similar to buttermilk, which is why this can be used as a quick alternative when you don’t have any.

INGREDIENTS

1 cup room-temperature milk
1 tablespoon white vinegar or fresh-squeezed lemon juice

INSTRUCTIONS

Combine

Mix vinegar or lemon juice with milk.

Set

Let the mixture sour for 5 minutes.

Devour!

FAQs & Tips

How to Make Ahead and Store

Keep in a well-sealed jar in the fridge for a couple days. Incorporate cold or at room temperature into any recipe that requires it. Perhaps it goes without saying, but sour milk shouldn’t be frozen. It’s made to be used within a few days of making it, lest it goes from sour to spoiled.

What’s the difference between sour milk and spoiled milk?

Typically, spoiled milk refers to pasteurized milk that’s gone bad. Sour milk, on the other hand, can be intentional (such as in this recipe) or it can refer to when raw milk has begun to ferment.

Is Sour Milk the Same as Buttermilk?

No, although the flavors are similar which is why they can be interchangeable. Buttermilk is a byproduct of the butter-making process. Specifically, it comes from the churning, which separates butter (the solid) from buttermilk (the liquid). The result is also tangy and creamy, but is fundamentally different from sour milk.

Serving Suggestions

As we’ve discussed, there are many recipes that call for sour milk to enhance the flavor and texture. But here are some of my favorites…

For starters, add a burst of tang to your Mashed Potatoes by replacing the sour cream in this recipe with sour milk. (It’s especially handy if you don’t have sour cream in the kitchen.) For a Southern comfort food that satisfies, use sour milk in Crispy Buttermilk Fried Chicken Tenders. Likewise, you can make these fluffy Buttermilk Pancakes for breakfast and use sour milk instead.

Lastly, if you’re craving a creamy and tangy drink, you can add a splash of sour milk to a classic Fruit Smoothie.