Yogurt is fairly easy to make at home, especially with electric pressure cookers like instant pot.

Then you can guarantee what goes into it.

You can make Kefir very easily. Is similar to yogurt but tastes better because it has also some additional yeast fermentation to the lactic acid.You do not need any device, just a lockable container and the bulb.

Where do you get cultures (or determine which are naturally present)?

just buy yogurt with live cultures. back when I used to make my own yogurt I would just put a tablespoon of dannon into a gallon of whole milk.

If you look at the box, it'll say active culture present. Any yoghurt with active culture will do. Once you have your first batch ready, you can reuse it.

And home made yogurt tastes sooooooo good.

I like to buy Bulgarian or Greek yoghurt and add jam to it. That way you can control the sugar content. Those types of yoghurts in particular also have a great, slightly sour taste that is great on its own once you get used to the relative lack of sweetness.

It's much cheaper to get a large tub of plain, unsweetened yogurt and add jam/honey/whatever to taste.

If the milk is good,almost probably good milk can find in Australia,, if that is your wish ate certain point, you can heat it until is hard(it kind of start to feel burn), to stay more than 10 seconds or around with finger immerse in milk.

Maybe for 3 liters of Milk you can use 2 around 200ml plain "natural" white yougurt cheaply sold.

I add honey most everyday, once a month brown sugar, or for variety aswell sugar cane syrup(what is superb, I have to say) on ocasions. First time better use only 1 liter of Milk only, to avoid waste if the mission goes unplannedly, for lack of training.

:for flavor: Is good for kids add redberries, or other color small berries, for adults, for magnesium, Almonds.