Kavasutra argues they do not sell kava as a food additive, but a root plant which is simply mixed with or brewed in water, and run it through a filter in the same way that coffee or herbal tea is made ...
Kava tea is pretty easy to make. Just grind up the leaves from a kava plant, add some water, an voila - relaxation in a cup. We all ordered large sizes, started sipping, and waited to feel something.