Muffins are less sweet than most cakes, and generally
have a somewhat more open crumb structure (a close,
fine grain is not desired). The shortening used is an all
purpose (nonemulsified) type to avoid more raising in
volume during baking. In some instances, a vegetable oil
shortening is used, when an extremely open texture accom-
panied by a moist mouthfeel is desired. Shortening levels
vary widely, from 18 to 35% based upon the amount of flour;
tenderness of the finished product varies accordingly.