Double check your bag, because they’re not interchangeable.

Nothing is worse than diving headfirst into a recipe, only to find you have the wrong flour on hand. Can you just use what you have instead? Not necessarily. We know the baking aisle can be confusing, but it’s essential to know your flours before you snag a bag. That way, you use what your recipe calls for and get the best possible results.

Two of the most commonly confused flours are all-purpose flour and self-rising flour, so we dove into what makes them different and why they aren’t always interchangeable. All-purpose flour is made from wheat. The germ and bran are removed (the stuff present in whole-wheat flour) leaving the endosperm to increase shelf life. The bag contains a mixture of hard wheat (with more gluten) and soft wheat. This kind of flour is perfect for most baking applications, thickening sauces, and coating meats and seafood. All-purpose flour contains between 10 to 12 percent protein, allowing it to form gluten that is essential to the structure of many baked goods.

Comparatively, self-rising flour is a mixture of all-purpose flour, baking powder, and salt that enables baked goods to rise without additional leaveners, but leads especially voluminous baking when combined with yeast. This variety of flour is ideal for making pancakes, muffins, or biscuits and contains about 8.5 percent protein to develop less gluten than all-purpose flour; thus, generally yielding a more tender product.

There are some cases in which you can substitute the same amount of self-rising flour for the amount of all-purpose flour called for in a recipe. If a recipe calls for ½ teaspoon to 1 teaspoon of baking powder per 1 cup of all-purpose flour, it’s safe to swap in self-rising flour. Just keep in mind to omit the baking powder and salt from the recipe if it’s ¼ teaspoon of salt per cup of flour; however, you’ll need to add more of these ingredients to compensate if the proportions are greater than self-rising flour. For example, this Blueberry-Peach Upside Down Cake calls specifically for 1 cup all-purpose flour and 1 teaspoon baking powder. In this case, you can safely replace the flour and baking powder with self-rising flour. Note that there is already about ¼ teaspoon of salt per cup of self-rising flour, so you’ll need to cut the salt as well.

This can go in the other direction too. If a recipe, like these Country Fried Beef Biscuit Sliders, specifically calls for self-rising flour, you’ll want to make sure you’re using the right kind. If you don’t have self-rising on hand, you can make your own self-rising flour by combining 1 cup of all-purpose flour with 1 ½ teaspoons baking powder and one scant 1/2 teaspoon of table salt. Just whisk together and get to cooking.