Melt butter over med.-low heat in med. saucepan w/ pouring lip, stirring occasionally. After several minutes, a foamy layer will bubble on top of melted butter.
Continue simmering until bubbling of foamy layer slows, approx. 5-10 min. Remove from heat. Let stand 5 min. Meanwhile, line fine-mesh strainer w/ 3-4 layers of cheesecloth.
Skim foamy layer off butter and discard or reserve for another use.
Pour melted butter through lined strainer into heat-safe measuring cup or mixing bowl w/ pouring lip, leaving behind bottom layer of milk solids. Discard solids, or reserve for another use.
Transfer clarified butter to clean, dry jar and seal. Let cool and refrigerate. Clarified butter should last 3-6 months.