Many bakers seem to put butter, margarine, and shortening in the same interchangeable category. They use whatever they have on hand and hope for the best. But, unfortunately, baked goods won’t turn out correctly if you start to substitute these three important fats. If a recipe calls for a certain one, use it. Baking is based on chemistry and you’ll throw the delicate balance out of whack if you start making up your own substitutions.
The three fats mentioned here - butter, margarine, and shortening - vary in their moisture and fat contents. And since baking is such a regulated science, each ingredient has a part to play that can’t be played correctly by any other.
Butter and margarine are up to 80% fat. You need that fat in order for your baked goods to turn out like the recipe dictates. Choose a good, well-known brand because you know they will have the right fat composition.
If you start throwing whipped spreads or shortening or reduced calorie baking sticks into the mix, you’re using an entirely different product. They contain loads more water than butter. Shortening will cause your cookies to spread beyond the required area. You’ll end up with flat, burnt cookies. Any shortening product or whipped spread can have as little as 35% fat. The rest is water and other suspect ingredients. Do you want that in your food? Not if you expect your baked goods to come out right.
Forget about trying to make due with whatever is on hand. Get yourself enough butter to last through the baking season. Keep some in the freezer so you never run short.
You may be wondering if oils, which are 100% fat, can be used instead of butter. Unfortunately, they are not an adequate or recommended substitute as they don’t whip into the sugar correctly. Since they are greasy, they will not cream up like butter will and you’ll end up with thin, crispy wafers instead of cookies.
If you’re wondering why shortening and margarine won’t do for your cookies, consider that they have a higher melting temperature. This means they’ll melt much slower than butter. This means you’ll get a tough, thick, extra chewy cookie when you didn’t want it to turn out that way. Shortenings and margarines also have no flavor, so your cookies will be missing that down home goodness that only butter can bring to the recipe.
What about the different types of butter? Does it matter if you use salted or not? You may not notice any taste difference, but you might. So to be safe, you should use unsalted butter and then just add the salt the recipe calls for. If you use salted butter you may throw off the delicate balance and end up with a cookie that is far too salty.
Finally, now that you know that butter is king in baking cookies, you should also know it needs to be in the right form in order to do its job. If a recipe calls for melted butter and you boil it down to a fine liquid in the microwave, you’re not going to get very good results. You may have done this in an effort to soften frozen butter, but you’re best to just let it sit out. Melting it completely changes the properties and it won’t whip up enough air into the batter.