Milk Here's something most fermentation guides won't tell you: your starter culture and temperature control matter far less than the milk itself. I know, I know. Everyone obsesses over finding the perfect yogurt starter or maintaining exactly 43°C. But after years of making yogurt and kefir at home, I've learned that milk is where the magic—or the frustration—really begins. That carton of milk sitting in your fridge? It might look identical to the one you bought last month, b