Figure 1.
Before creaming, butter must be brought to cool room temperature (about 67 degrees) so that it is malleable but not soft. Don't hurry this step. Cold butter can't hold as much air as properly softened butter, and the resulting muffins and quick breads may be too dense. If you don't have an instant-read thermometer to take the temperature of the butter, use these visual clues: (A) The butter should give slightly when pressed but still hold its shape. (B) The butter should bend with little resistance and without cracking or breaking.