Clarifying butter is as simple as melting butter and letting the milk solids settle or rise out of the fat. Care should be taken not to burn the butter while heating it, so use a heavy pan that doesn't have any hotspots (see Common Materials of Cookware for more information on hotspots). When using salted butter, it is difficult to guess how much salt will remain in the clarified butter. A lot of the salt can be found in the milk solids as it settles or foams up, but the exact amount will be different every time. Use unsalted butter to remove any uncertainty (you can add salt to the clarified butter later to achieve the desired saltiness).
To make approximately 3/4 cup of clarified butter, melt one cup (225 g) of butter in a small saucepan (a 1-quart saucepan is shown in the picture) over low heat. With a good saucepan, you can just leave it there over low heat while doing something else and the butter will slowly melt. Turning up the heat will melt the butter faster, but the milk solids may begin to burn, so, resist the temptation. Instead, you can cut up the butter into pieces to speed up melting. Also, if you don't have a small saucepan, it may be best to use more butter. Too little butter in a large diameter pan will make it difficult to separate the solids from the fat later.
When the butter has completely melted, continue to heat it over low heat. Some milk solids will drop to the bottom of the pan while others will rise as foam. As the milk solids rise to the top, they can be skimmed off. (Or, it can be removed when the butter cools.)}?>
Alternatively, pour the hot melted butter through cheesecloth to filter out the foam and solids that have settled, catching the clarified butter in a jar.
Or, pour the hot butter into a container, allow it to separate while cooling and then refrigerate. After it has solidified, you can easily scrape off the hardened foam from the stiff clarified butter layer.
Although pure clarified butter does not need to be refrigeration, I recommend you store your clarified butter in the refrigerator (some milk solids may still be present and may cause the butter to go rancid). Use the clarified butter as you would use regular butter (tablespoon for tablespoon) in recipes.
Robert Wolke, in What Einstein Told His Cook, suggests using the left over milk solids for topping popcorn. Sounds like a good idea to me! (Also, Wolke mentions that no lactose is in clarified butter, so lactose-sensitive individuals should be able to enjoy clarified butter without the uncomfortable effects those of us who are lactose intolerant are well aware of.)}?>