Butter's Role in Baking
In baking, butter's job is to contribute to the richness (the heavy, velvety, indulgent feeling when you take a bite), as well as provide tenderness and structure. That's why, when you reduce the fat in a recipe, the texture and flavor change.
It also provides moisture, intensifies the flavor of other ingredients, and contributes to the rising of your baked goods.
Types of Butter
The two types most people are familiar with are salted and unsalted. Most baking recipes call for unsalted butter.
Why call for unsalted butter, just to add salt separately? The amount of salt in different brands vary, and it's not easy to tell how much is in each brand. So, it's easier to control the amount of salt in your recipe if you use unsalted and add salt separately.
Other types of butter include:
- European: European butter has a higher fat content than American butter, leaving less room for butter solids and water.
- Cultured: this is butter made from cream that has been fermented with live bacterial cultures before it is churned. The result is a deeper, richer, nuttier, and slightly tangy flavor, and a denser, smoother texture. Some cultured butters have a higher fat content than American butter, but not all.
- Clarified (aka ghee): this is butter that has had all the milk solids and water removed. It's not often called for in baking. Most often, you'll see it in recipes for pastries that have an extremely crisp texture.
- Browned butter: this is butter that has been melted and kept over low- to medium-heat until the milk solids start to turn brown. This causes the flavor of the butter to develop notes of caramel and hazelnut.
Methods of incorporating butter
There are different ways of incorporating butter into a recipe, and it will affect the final baked product.
Creaming: this is when you beat together the butter and sugar. Most amateur bakers don't let this step last long enough. Because this isn't just about combining the butter and sugar. It's about incorporating air, too.
Ever make a recipe that says it yields 36 cookies, but you only got 30? You may not have creamed your butter and sugar long enough. Yes, adequate creaming increases your yield! Adequately creamed butter and sugar incorporates air, giving you not only more cookies, but less dense cookies.
Cutting: also called "rubbing," this is when you want small, solid bits of butter in your dough that will later melt, and give your baking a flaky texture. This is common in pie crusts and biscuits.
A common mistake that people make is they let the butter get warm as they incorporate it into their dough, whether they take too long cutting it in with a pastry blender, or their hands get too warm while rubbing the butter into the flour with their fingers.
Personally, I like to cut the butter into the flour with a food processor, but it can be very easy to over-do the processing. Another "hack" is to freeze your butter, then shred it on a box grater and toss the grated butter with your flour mixture.
Any way you choose to accomplish this, the most important thing is to keep your butter cold! Otherwise, you lose the air pockets that cutting your butter in creates, and you won't end up with a flaky texture.
Kneading: this is most commonly done in brioche and other enriched bread doughs. These doughs are often kneaded for a time first, then butter is kneaded into the dough. If you kneaded in the butter from the start, it would coat the flour protein and prevent gluten strands from forming, and your bread wouldn't rise. By kneading in the butter later, you continue to create gluten strands, but the fat in the butter keeps them short. This results in a bread that rises, but is also tender.
Melting: When you are aiming for a dense, chewy final product (like brownies), you want to reach for melted butter. As noted above, butter is a mixture of milk solids and water. When the butter melts as it is baking, it creates steam and helps the final product rise. When butter is already melted before the baking starts, it blends into your batter with holding onto air, which keeps the final product from rising.
Butter Temperature
What does "softened" mean, anyway?
Softened butter has sat at room temperature long enough to still feel cool to the touch, and still offers slight resistance when pressed, and leaves a shallow thumbprint without feeling mushy. You should be able to bend the stick of butter without it snapping (if it snaps, it's too cold). It should not look greasy (if it does, your butter is too warm).
If you want to be really sure, use a probe thermometer. You are aiming for an internal temperature of around 65 degrees F.
Why does it matter if it's a little too cold or too warm?
Butter that is too cold won't mix in evenly. Butter that is too warm in, for example, cookies, will coat the flour proteins, causing your final product to spread too much.
If you're making true buttercream (not the American style), adding butter that is too cold will cause the buttercream to seize (it will look lumpy, grainy, sort of like cottage cheese), and if it's too warm, the buttercream will remain runny instead of thickening up.
Why can't I microwave my butter to soften it?
Microwaves cause uneven heating. Your butter could be warm or even melting on the outside and cold in the middle. If your butter is too warm, it could melt the sugar during creaming, which prevents it from incorporating air.
Fast methods of softening your butter include filling a glass jar or bowl with hot water, emptying it, and placing the hot jar or bowl over your butter for about 5 minutes, or, cutting your butter into cubes. The more surface area something has, the faster it warms up (think about it - a sliced Thanksgiving turkey cools faster than whole Thanksgiving turkey).
Do I need to start over?
Some butter mistakes will mean you need to start over. These include:
- Using too-warm butter in creaming. Once you melt the sugar, you can't unmelt it.
- Using salted butter AND adding salt. We've all been there, you grabbed the wrong stick of butter. Or it was all you had, and you forgot that you needed to omit the additional salt from the recipe.
- Too-warm butter in pie dough. It's not that you won't get an edible pie crust, but once butter warms to the point that it coats the flour instead of the flour coating chunks of butter, it won't have that flaky texture.
But not all mistakes mean you need to start over! These include:
- Too-cold butter in buttercream. You've got a grainy mess. Warm the bowl slightly by placing the bowl in a warm water bath, or blowing it for a minute or two with a hair dryer set on hot. You want to slightly warm the contents of the bowl to bring up the temperature of the butter.
- Too-warm butter in buttercream. Pop the whole bowl in your refrigerator for about 15 minutes before continuing to beat the buttercream.