Ingredient Spotlight: How Fats are Used in Baking
I’m highlighting common baking ingredients in an attempt to learn more about the science of baking and the role each ingredient plays in the bigger picture. See more on my Baking Essentials page. A quick disclaimer: I’m just a gal with a library card and a desire to learn. If you have any insights you’d like to share, please leave a comment!
The next ingredient I want to talk about is butter, which is perhaps my most favorite. Who doesn’t love butter? But while doing some reading I realized that it probably would be better to take a step back and talk about all fats used in baking– butter, shortening, oils, and lard. Let’s jump in!
What are fats?
I’m going to get a little bit nerdy for a moment and talk about fatty acids. A fatty acid is a long carbon chain that interacts with hydrogen atoms differently and can be saturated, polyunsaturated, and monounsaturated based on this relationship. Three of these fatty acid chains together form a triglyceride.
Why is this important? Because different types of triclygerides behave differently in baking. Triglycerides high in saturated fat tend to come from animals and are solid at room temperature, like butter or lard. Triglycerides high in unsaturated fats usually come from plants and are liquid at room temperature, like vegetable oil.
Vegetable shortening is solid at room temperature because it goes through a process called hydrogenation where hydrogen is forced to bond with the carbon chain in a way that mimics a saturated fatty acid. You’ve surely heard the term “trans fat”, and that refers to the synthetic compound that results from fatty acids that go through this process.
How and why fats are used in baking
Fats have four main purposes in baking:
- They tenderize the product by coating and weakening the gluten bonds within the structure.
- Even though they contain little or no moisture, they provide the illusion of wetness. Fats don’t evaporate or become absorbed with heat like water does.
- They enable browning.
- They help move heat through the product, perpetuating the baking process.
Now that we’ve got a bit more of an understanding of what fats do, let’s talk about the different kinds we use.
Butter in the US contains approximately 80% butterfat, in Europe it’s roughly 85%. Water makes up most of the rest and its presence can be both a good and bad thing. It turns to steam during baking which assists in leavening, but it also adds additional moisture that can affect the overall structure. Water can also cause the butter to go rancid, so salt can be added as a preservative.
Butter is used for its superior flavor over other fats. We can all tell the difference between a homemade cookie baked with butter and one from the grocery bakery made with shortening, right? Butter also has a melting point just below body temperature (90-95 degrees F) and so it melts nicely in the mouth. Butter has a narrow plasticity, however, and is best when at room temperature (65-70 degrees F). I usually let it sit out on the counter 30 minutes before I need to use it and it’s just right.
Butter is used in baked goods in three typical ways. It can be cut into the dry ingredients, as with biscuits and pie crust. It can be creamed with sugars in things like cakes and cookies. And it can also be melted and combined with other ingredients. One interesting thing to note about butter is that it is the same whether weighed or measured by volume. One liquid ounce of butter is the same as one ounce of butter.
Shortening was invented in the early 1900s and got its name because fats shorten the gluten bonds by lubricating them and weakening the structure. Shortening is useful in baking because it remains plastic at a much wider temperature and contain emulsifiers that help batters come together faster. It’s also 100% fat, unlike butter. These reasons, as well as the fact that it does not need to be refrigerated and is much cheaper than butter, are why it has been so popular.
It’s fallen out of favor in recent years partly because hydrogenated fats are believed to be worse for you than other natural fats. Shortening also doesn’t have a great flavor, and because it has a higher melting point it doesn’t have a pleasant mouth feel (think of the coating in the back of your throat after you’ve had a piece of store-bought frosted cake).
Margarine is similar to shortening in that it’s made from hydrogenated vegetable oil, but it has had milk products (usually skim milk) added as well so that it’s a more suitable butter substitute. While shortening does have a place in baking, margarine is a product I never use.
Oil is completely fat, it contains no proteins, solids, water, or air. It doesn’t have the capability of trapping air bubbles, so the creaming method doesn’t work. And because there is no water, oil doesn’t produce steam and help with leavening. But oil does create very moist baked goods because oils are naturally liquid at room temperature. Some of most moist cakes I’ve had have been baked with vegetable oil.
Examples of vegetable oils include soybean, peanut, cottonseed, corn, canola, etc. Each have slightly different properties, but I use basic canola or a canola blended oil for baking.
Up until about 100 years ago lard, which is fat from a pig, was perhaps the most popular fat used in the kitchen. In baking it’s used much like butter. Although the invention of shortening made lard an outcast, its slowly making its way back into kitchens and recipes.
Butter should be stored in the refrigerator, but if keeping for more than a few weeks, tightly wrap it and place in the freezer. It will stay good there for up to 6 months.
Shortening and oil can also go rancid if exposed to light and air. Cover and store in cool, dark place and try to use them within a few months of purchase.
A lot of people try to make recipes healthier by substituting the fats with something else. Applesauce, for example, is a common substitute in baked goods like cakes and cookies. Feel free to try substitutes like this, and best of luck to you. But since I generally don’t do substitutions, I don’t have enough experience to advise you on them.
I’m a butter gal all the way, I don’t usually use anything else. And now I know more than I ever wanted to know about what it’s doing in my baked goods.
Any questions? Leave comment and I’ll do my best to find an answer!