Both butter and shortening are common fats used during baking. This fat is essential as it produces the correct flavor and texture in baked goods.
When mixed into the dough, the fat coats some of the flour, preventing it from reacting with liquid and making excess gluten. This gives cookies a tender consistency. Moreover, fats add moisture and flavor.
Butter is 80% fat from milk and about 20% water. Since butter has a lower melting point than shortening, 98.6° F and 115° F respectively, it melts and spreads more quickly, creating flatter, crispier cookies. Additionally, the water in the butter turns to steam, producing air pockets. This gives scones and biscuits fluffy layers; however, the moister may react with the flour, yielding more gluten. If baked for too long, cookies might become tough. Nevertheless, butter provides a signature taste that even butter flavored shortening cannot replicate.
On the other hand, shortening is 100% fat made from vegetable oil such as soybean or cottonseed. Due to its higher melting point, the cookie dough sets before the shortening fully melts, so cookies bake taller and thicker. Shortening also does not produce steam, so cookies remain softer and slightly denser. Since shortening does not contain water, cakes baked with shortening are very dry. Most importantly, shortening lacks that distinct buttery taste.
To make shortening, vegetable oil is solidified through hydrogenation. During hydrogenation, hydrogen is bubbled through hot, pressurized oil. The hydrogen bonds to the ends of the fatty acids, saturating the molecules.
Saturated fatty acids contain no double bonds between carbon atoms. At room temperature, most saturated fats are solid due to high melting points.
Moreover, the melting point of a substance depends on it intermolecular forces – attractions that hold the molecules together. In order for a substance to melt and later boil, these forces must be broken. This process requires energy or heat. Stronger intermolecular forces need more energy, and therefore have high melting points.
Fatty acids are long chains, relatively linear with zigzags. Saturated fats easily stack on top of each other, and intermolecular forces hold the molecules tightly together. However, unsaturated fats contain double bonds, which create an extra bend in the molecule. This prevents them from stacking as closely as saturated fats. Due to weaker intermolecular forces, these molecules are easier to break apart and their melting points are slightly lower.
Furthermore, since saturated fats are more stable than unsaturated fats, shortening has a very long shelf life. Butter, however, is only about 50% saturated, so it eventually breaks down and spoils.
Although saturated fats have a bad reputation, they do not cause heart disease and are actually healthy when eaten in moderation.
When baking, it is best to use a combination of both fats to achieve the best taste and texture. In this recipe, equal amounts of butter and shortening create perfect, tender sugar cookies.
The dough begins with butter, shortening, and sugar, all creamed until they are light, fluffy, and pale.
After the dough is complete, form into balls, roll in colored sugar, and press with the bottom of a glass.
Since the cookies are made with a good amount of shortening, they hold their shape in the oven. They expand slightly, but do not flatten while cooking.
If you want the cookies to stay soft, remove from the oven before they brown. However, make sure the cookies are completely cooked! Don’t take them out until the outsides of the cookies form soft crusts, and the middles set.
To package the cookies, I wrapped them in plastic and added a bow. I shared these adorable treats with my teachers to thank them for a wonderful year.
1/3 cup butter
1/3 cup butter flavored shortening
3/4 cup sugar
1 tsp baking powder
1/2 tsp salt
1 3/4 cups flour
Preheat the oven to 350ºF.
Cream together the butter, shortening, and sugar. Add the egg, vanilla, baking powder, and salt. Slowly mix in the flour.
Spoon out dough and form 1 inch balls. Roll in colored sugar, place on parchment lined pan, and press with the bottom of the glass.
Bake for 10 minutes, or until the cookies set. Remove before the cookies brown for a softer cookie.
Makes 24 cookies.
Thanks to these websites for the information on fats.