Preheat the oven to 300°F (150°C). Take your 16 oz (455 g) or 2. 0 cups (32 tbsp) of unsalted butter and cut it into smaller 4 oz (115 g) or 0. 5 cup (8 tbsp) portions to ensure even melting.
Place these chunks into your heavy-bottomed pan, making sure there is at least 3. 0 inches (7. 5 cm) of clearance between the top of the melted butter and the rim of the pan.
Bake the butter uncovered and entirely undisturbed. For a standard 16 oz (455 g) batch, check it after 1. 0 hour. (Note: Larger stockpiles will take longer; for example, 30 lbs (13. 6 kg / 13.23 lb) can take up to 12. 0 hours). The Oven-Method Ghee is finished when you see a solid crusty foam on the surface, clean amber-gold liquid in the middle, and pale gold solids settled at the bottom.
Carefully remove the hot pan from the oven.
Using a fine-mesh wire skimmer or a large 1. 0 tbsp (15 g / 0.53 oz) metal spoon, gently skim off the crusty top layer of foam and transfer it into a small 4 oz (115 g) or 0. 5 cup container.
Ladle the clear, amber-gold Oven-Method Ghee through a strainer lined with four layers of cheesecloth into a clean bowl. Stop ladling when only 1. 0 inch (2. 5 cm) of liquid remains at the bottom, and carefully scoop the last bit of clear ghee out with your spoon to avoid disturbing the gelatinous solids.
Allow the filtered Oven-Method Ghee to cool down slightly, then transfer it into a 16 oz (450 g) or 2. 0 cup glass storage jar. Label the jar, wait for it to reach room temperature completely, and then secure it tightly with a lid.
Gather the remaining 0. 1 cup (about 25 g / 0.88 oz) of golden bottom solids and mix them into your reserved crusty foam. Store this flavorful mixture in an airtight container in the refrigerator for up to 3 to 4 days, using it in portions of 1. 0 tsp (5 g / 0.18 oz) to enrich creamed soups or sandwich spreads.
Keep Moisture Away: Water is the enemy of shelf-stable ghee. Ensure your storage jars, spoons, and strainers are completely dry before use. Even a drop of water can cause your beautiful stockpile of ghee to spoil prematurely.