Now a days, everyone is selling "shuddha desi ghee" (fat derived from cow/buffalo milk). But you never know if the this ghee is really shuddha or pure.
One of best ways I know of getting a pure ghee is to prepare it at home. But we are too busy to do anything like that.
So how to identify a pure ghee? Well, just buy the smallest pack available on the shelf and put about 5-10 ml of ghee into a small (about 100 ml) gar jar with an airtight lid. Now shake this jar well so that the ghee spreads into it evenly.
Now put this jar into refrigerator for 10 minutes so that ghee is solidified. Now pit this jar out in the sun. If whole of ghee melts pure clean liquid is accumulated at the bottom then it is a pure ghee.
And if there is a whitish residue on the walls of a jar then this is nothing but what was added to ghee to increase its volume.
I hope this helps everyone identify the pure ghee and not fall pray to adulterated food and food articles. So live better.