I am sorry, if I misunderstood you. With the label probiotic, around here normally are mentioned all kinds of yoghurts that are from company like Nestle and so on, and that are not any else then any other normal yoghurt.
So I didnt know, that you meant an normal, natural done yoghurt, with the label probiotic. I tried to do selfmade yoghurt for some time on my own, but had problems because of the natural cultures needing normal cow milk, instead of that already sterilized of supermarkets and so on. Then you always had to keep a part of it and care for it like a plant, so that you could use that leftover for the new milk, to create yoghurt from that again. Additional you always had that work with sterilizing the pots, so that the fresh yoghurt didnt go bad that fast.
Because of us having many local diaries here, the additional work had no use for me, because of the diaries around here creating as well normal natural yoghurt, without any sugar added, so simply plain yoghurt, which is probiotic by itself. But if you cant buy normal natural yoghurt anymore around your place I would start creating that again, so I use yoghurt a well for cooking and sauces a lot, so having none would suck.
I am simply whondering about the "powder" you mentioned, and additional, if there are no more normal farms or diarys producing normal yoghurt anymore, where do you get the fresh cowmilk from?