Some Butter Basics

• Butter isn't a fat in itself, but a complex mixture of fats, water and solids. Those fats assume a definite crystalline structure when the butter is churned, and butter can be hard and brittle when it's chilled. When slightly warmer, the butter can be kneaded by hand or beaten in a mixer, and bakers often combine it at this stage with sugar to create a light and fluffy base for cookies or cakes. The butter's fats are stiff enough at that stage to hold their shape, trapping air in tiny pockets. When you make or buy whipped butter, you're taking advantage of that same characteristic.

Whipped Butter

• The simplest form of whipped butter is exactly what the name suggests. It's butter that's whipped to incorporate air, making it light and fluffy in the same way whipped cream becomes light and fluffy. The added air makes it soft and spreadable even when cold, making it more convenient for sandwiches or toast. It can go farther if a small amount of oil, milk or water is beaten into the butter, which increases its volume further and reduces the number of calories in a given spoonful of butter. When you use your whipped butter for cooking, that collapses its light and airy structure and reduces it to a melted, liquid mixture.

Cooking With Butter

• When you put ordinary butter in a skillet, to fry an egg or other food, it breaks down in a few recognizable stages. First, the solid lump of butter melts into a puddle of fat and milky-looking fluid. It foams for a few moments as it reaches cooking temperature, then begins to brown and develop a toasty aroma. Whipped butter does the same things. If all you've added to the butter is air, it will simply make a smaller puddle than ordinary butter. Whipped butter with milk or water in it will foam longer, because that foam is the moisture boiling away. In either case, it's only suitable for low-temperature pan-frying, not high-temperature sauteing.

Clarifying Butter

• Butter doesn't work well for sauteing because plain butter, with or without added water, milk or oil, has a relatively low smoke point of approximately 250 to 300 degrees Fahrenheit. Above that temperature, the milk solids that give it much of its flavor will scorch and create unpleasant flavors. To saute with butter or whipped butter, you'll need to clarify it. Melt the butter in a microwaveable measuring cup or small saucepan, and skim off the small raft of solids that floats to the top. Then, ladle off the clear fat, leaving the milky-looking fluids at the bottom. That purified or "clarified" butter fat can be used at temperatures of about 400 F, suitable for sauteing most dishes.