What Is Cream of Tartar—and What Does It Do?

Cream of tartar has a rather deceptive name—it’s not creamy and it (thankfully) has nothing to do with teeth. Here’s everything you ever need to know about the baking essential:

What is Cream of Tartar and How Is It Used?

Cream of tartar (potassium hydrogen tartrate) is a white, powdery, acidic substance that’s often used to stabilize whipped egg whites. In other words, it allows the beaten whites to reach their full volume by helping them hold in water and air.

This is especially helpful when you’re making light and fluffy desserts like meringue or angel food cake.

It’s also commonly used as a leavening agent (a substance that releases gas and causes a mixture to expand and soften) in conjunction with baking soda. When combined with baking soda, cream of tartar produces carbon dioxide—the same gas that’s released by yeast in bread baking.

Believe it or not, this baking staple is actually a byproduct of winemaking. After wine is drained, the residue left behind in the barrel is potassium hydrogen tartrate.

Cream of Tartar and Snickerdoodles

WATCH: How to Make Snickerdoodles

There are two reasons cream of tartar is listed among the ingredients in most snickerdoodle recipes: texture and taste.

Adding a teaspoon or two to cookie dough prevents sugar from binding together and forming crystals, a natural chemical reaction. This results in a soft, pillowy cookie texture.

Cream of tartar is also responsible for the snickerdoodle’s signature slightly acidic tang that cookie connoisseurs are able to pick up on immediately.

Cream of Tartar Substitute

What do you do if your recipe calls for cream of tartar and you don’t have any in your pantry? There’s no perfect substitute, but lemon juice or white vinegar should work to stabilize egg whites in a pinch.

Our friends at Cooking Light recommend using 1 teaspoon of lemon juice or white vinegar for every ½ teaspoon of cream of tartar called for in a recipe, or ½ teaspoon lemon juice or white vinegar per egg white.

Can It Cure Migraines?

Many people tout cream of tartar as an effective treatment for migraine headaches—but is it really? Probably not, according to Snopes.

It’s not clear where the idea of cream of tartar as a headache remedy came from, but the claim has been circulating on social media for at least the last few years. Bizarrely, some cookbooks even warn that the potassium-rich substance can cause migraines.

That’s not to say cream of tartar won’t help your headache—there’s just no scientific research proving that it does or doesn’t.

If you choose to try it as a home treatment, you should be aware that at least one study has found a connection between excessive cream of tartar consumption and a potentially fatal condition called hyperkalemia, or high levels of potassium in the blood.

You almost certainly won’t experience side effects from the amount of cream of tartar used in recipes for snickerdoodles or lemon meringue pie. However, you should check with a doctor before using it in excess as a natural remedy.