Heat organic butter over low to medium heat, being careful not to burn, until all of the butter is melted.
Put the pan in the freezer for about 4 minutes to solidify the foam (containing casein) on top. You may need to chill it a few minutes longer if you're making a large amount.
Pour through fine mesh strainer.
Tip: You can also line your mesh strainer with cheesecloth.
Please note: I can not personally guarantee that ghee you make yourself will be casein-free. I can only tell you that my family has never had any problems with our own home-made ghee, and we save a fortune making it ourselves.