Trim off any meat or connective tissue, then cut the fat into small 1-inch cubes to ensure even rendering.

Place the fat in a slow cooker or pot on low heat. Add salt and just enough water to cover the fat. Stir occasionally and allow it to melt slowly over several hours. As the fat renders, gristly bits will sink to the bottom, and the liquid fat will turn golden.

Once fully melted, carefully strain the liquid fat through a fine mesh strainer or cheesecloth into a large bowl. Allow it to cool and harden—refrigeration speeds up this step. The impurities will separate and settle at the bottom.

Once hardened, remove the tallow from the bowl, leaving behind the brownish water. Scrape off any remaining sediment from the bottom of the tallow.

Repeat the process: Place the tallow back into the slow cooker or pot, adding the same amount of salt and water. Simmer for about an hour, then strain, cool, and scrape off any remaining impurities. Repeat again if needed until the tallow is clean and white.

Strain the liquid tallow into a glass jar or a silicone mold and let harden. If using a silicone mold, transfer the tallow to a storage container once hardened. Store in a cool, dark place or refrigerate for extended shelf life.