500 gm to 1 Kg ( 1 to 2 lb) pure unsalted butter.
Slice into 50 gm ( approximately 2 oz) blocks and place in a heavy base pan.
Place on medium heat and allow the butter to melt and boil. Do not stir the boiling contents. A white top will be seen and this will settle to the bottom and turn to a brown sediment.
This process can take 20 minute to 30 minutes and the boiling will stop. The aroma of freshly baked croissants becomes obvious. Turn off the heat immediately as it may burn quickly at this stage.
Allow the ghee to cool then carefully tip off the golden ghee without disturbing the sediment. This can be filtered through cheesecloth to remove the remaining sediment. The Ghee can be stored in glass jars at room temperature. It is a saturated fat so depending on the room temp can be liquid or solid. It should be stable for many months at room temperature.
It is always good practice to mark the date of processing on the storage vessels.