This is the best method for making a stockpile of ghee. Because the heat surrounds the ghee, rather than contacting only the bottom of the oan, the cooking is slower but almost effortless. More of a crust will harden on the surface, and the solids at the bottom of the pan will remain soft and somewhat gelatinous. Adjust the pan size to the quantity of butter you are turning into ghee. Always allow 3 inches (7.5 cm) of pan above the surface of the melted butter.
1. Preheat the oven to 300 f (150 C). Place the desired quantity of unsalted butter, in ¼ -pound (115 g) portions, in a heavy-bottomed, thick-walled pan. Allow the butter to melt and slowly clarify, uncovered and undistributed, until there is a layer of solid foam on the surface, clean amber-gold ghee in the middle and lumps of pale gold solids on the bottom. Remove the pan from the oven. Depending on quantity, 1 pound (455 g) could take as little as 1 hour; 30 pounds (15 kg) could take 12 hours or more.
2. Skin off the crusty foam on the surface with a fine-mesh wire skimmer or a large metal spoon. Place the foam in a small container.
3. Layers of cheesecloth. When you have removed as much as you can without disturbing the solids, skim off the last 1 inch (2.5 cm) with a large spoon. When the ghee has cooled somewhat, pour it into storage containers, label and, when at room temperature, cover with a tight-fitting lid.
4. Add the remaining ghee and lumps of golden solids to the reserved foam, and use it for anything from creamed soups to sandwich spreads. Keep covered and refrigerated for up to 3-4 days.