Here's my recipe:
I have used as an approach a good natural yoghurt. One should take one that contains only a single bacterial culture, because you can not get the balance in the long run. The approach is needed only once, the culture can be - if you work hygienically - endlessly propagate.
If a yogurt pack is empty, I take a new, room warm Tetra Pack low fat UHT milk (1.5%) and pour about 100ml into a glass from (for drinking, that we need some space) and give about 200ml in the previous (almost) empty tetra pack with yogurt. The shake and the resulting yoghurt milk mixture back into the new Tetra Pack pour. Through the rest of the yogurt-old Tetrapack we he in spite of the removed 100ml of above fully.
Lid on, shake the pack short and off in the yogurt maker.
I'm making the yogurt-maker - controlled by a timer - 8 hours in and leave the pack after that cool off before he comes over night in the refrigerator.
As timer I use this here, because you can directly call 8 hours:
Shake again briefly before pouring. The consistency is such that you can just pour it into a glass and drink.
I always parallel several yogurt packs in the fridge, then go one not during the preparation of the delicious homemade yogurt.
The whole thing is very hygienic (the yogurt comes only with the tetra packs in contact) and you have not flush (except glass or bowl for digestion). There is also no waste except the Terapacks, from which came the milk.
And it comes with a little practice in a minute.
It was a great acquisition, I would buy the part at any time!