Is store bought kefir dead from pasteurization and thus a waste of time? Well a waste aside from the taste.
*I don't know if they pasteuri*ze it or not… I just assumed as a liquid dairy product it would probably have to be pasteurized to sell it. If it weren't wouldn't it continue to ferment on the shelf and pop and spray goop around on the shelf.
It just seems you ferment it for such a short period of time at home, and it's only good for such a short period of time that it must be dead.
It's not dead, but it doesn't contain most yeasts or most bacteria strains, so it's kind of limited healing abilities: http://ezinearticles.com/?Homemade-Kefir-Vs-Commercial-Store-Bought-Kefir&id=4512536
I personally do my own kefir, from goat milk.