Turn your heat to medium-low.
The white foam that is on top is milk solids. I used a silicone spatula to move the milk solids, allowing me to check the color and transparency of the butter fat below.
Your butter may begin "popping" at this point. That is the water that is in your butter. Turn the heat down if this happens.
and discard it. It is super airy and very salty. I read somewhere that this is good for popcorn...
It did not work that well.
If you have a coffee filter or cheesecloth, that may work better.
I just poured it into another container, being extra careful not to pour the white stuff in...
Since this butter does not have any milk in it, you can leave it at room temperature for up to a month without it going bad. In your fridge, 6 months. In your freezer, a year.
Special Thanks for the Reluctant Gourmet for video demonstration ~