The store bought stuff is inert. Ive been fermenting for 20 years. You can test it (or yogurt) easily by trying to rebatch it. take a scoop and and put in fresh milk and leave on counter. You should see some fermentation over night and a lot in 24-36hrs.

Ive tested many Kiefer brands and I’ve bot come across one you can rebatch.

-Oh and don’t worry about the temp, just order some. The first few batches might be weak but you’re over thinking it.

🧡🍻👊🏻🥩