So many cake and cookie recipes say to cream together the butter and sugar. Why is this done and how do I do it right?--Amber
To cream butter means to beat it together with the sugar in the recipe until it is light in color and no sugar crystals are visible. With white sugar, the butter will take on a light yellow color, almost white. If your recipe uses brown sugar, then the color will turn to a light tan. While it is possible to cream butter by hand, it is much faster and more convenient to use an electric mixer. The purpose of creaming is to incorporate air into the butter to help leaven the final product. According to Corriher, creaming is perhaps the most important step in making good cakes.
Creaming also softens the butter and makes it easier to blend with the other ingredients.
To cream butter properly, start with cold butter. While some recipes say to start with butter that has been allowed to soften until nearly room temperature, this runs the risk of having it become too warm during mixing. T0 trap air bubbles, it has to remain below its melting point of 68°F (20°C).
I usually start with butter straight out of the fridge which I rough cut into small cubes, maybe about a quarters of an inch (2 cm) to a side. Exact size doesn't matter. Put the butter into the mixing bowl and blend at slow speed until it starts to soften, then add the sugar. Beat for 5 to 10 minutes, depending on the power and speed of your mixer. As long as the butter remains cold enough, there is no risk to beating it for too long.
During beating, friction from the beater may warm the butter and it may start to melt. If this happens, then put the mixing bowl and beaters into the fridge until the butter becomes firm again, about 15 to 30 minutes, and then pick up where you left off.
Remember during this step to stop occasionally and scrape down the sides of the bowl so that all of the butter is creamed, otherwise it may not blend completely with the other ingredients and could affect the quality of the final product.