Clarify

To clarify a liquid is to ensure that it is clear by removing any impurities. This is usually done with careful skimming as it simmers. When it cools, strain it through a fine-mesh sieve or cheesecloth.

To clarify butter, melt it slowly until most of its water content evaporates. The milk solids will sink to the bottom and gold-colored liquid will remain at the top. Skim off the foam and use the clear butter for your cooking.