1 kg unsalted butter
Method
Put the unsalted butter in a heavy bottomed pan. Kepp on medium or low flame. Stir occasionally while heating. Heat till you get the pure smell of ghee and a brownish crust is formed at the bottom.
Remove from heat immediately. Don't allow the brown crust to become black or else it will leave a burnt flavor in the ghee. Let it cool down thoroughly. Store only the yellow liquid which floats (or solidifies if the weather is very cold) on top in a airtight container. According to Ayurveda the ghee contains fat which is hot in nature and when taken in small quantities everyday, helps to nourish all the tissues in body. 1/4 teaspoon of ghee eaten in the morning every day can help in weight loss as it kindles the agni or heat in the digestive system. The brown crust which is formed at bottom when making the ghee contains helps to gain weight and strength. The crust part can be separated from the yellow oily ghee and can be mixed with the dough of roti or chappatis. Or it can be mixed with a little milk, cream and sugar to make halwa. It is excellent food for toddles and young children who are very active.
I usually make ghee from 1 kg butter and keep only a small quantity required for a month's use. Storing in the freezer helps keep the ghee to retain its flavor over the course of time.
Tips & Caution: My mom always advises to be "inside" the kitchen when you are making ghee. There have been cases where people have wandered to complete other chores and the ghee catches fire due to over heating. If the ghee catches fire, just switch off the gas and cover the vessel with a lid to cut off the air supply for the fire. Never make the mistake to pour water over the burning ghee as it will splutter and cause serious burns. Ghee should be removed from heat once it is done; especially if you are heating it on a coil heater like in many homes in US.