It's Russian stuff
Russians like this thing. In Soviet time, people would send kids to buy kefir from the stores, like Chinese kids used to be send to buy soy sauce, with a bottle from home. It gets very thick at my home so I don't really like it. The correct way is to drink it like milk in a liquid form, not as thick as yogurt. Mine just sits at the back of my fridge. I don't want to touch it again. The process takes too much work. You have to constantly filter it, observe it. I got tired.