The container must be able to maintain the temperature at ~37 degree Celcius or our body temperature for at least 6 hours.
I think the information below would be useful before you start making your own homemade yoghurt:Technically, yoghurt can be made from any sort of milk – cow, goat or ewe – but it must be fermented before it can be called yoghurt.
A small starter culture of the bacteria is added to fresh, warmed skimmed or whole milk and then the mixture needs to be kept at about 37 degrees Celsius for about 12 hours.
The bacteria multiply in the warm conditions, feeding on the sugars in the milk. They ferment lactose, the disaccharide sugar in milk, producing lactic acid. This causes the milk to curdle, forming curds and whey. The curds are the yoghurt and the whey is the watery fluid that is poured off, leaving a rich, creamy thick yoghurt.
Great tips that I find helpful:
1. If after 6 hours, you find that the yoghurt still hasn't really formed yet (still in liquid form), you can actually wait longer (leave it overnight or another 6 hours). Maybe the 'live' culture needs more time to grow.
2. Also, if you want to add fruit flavours to it, especially from fresh fruits, you need to add this after the yoghurt has incubated. That's because the acid content of some fruits can curdle the milk-yoghurt mixture and prevent proper fermentation.
I find this process rather easy even for busy moms, and I've been blending them with fresh mango and even dragon fruits for my kids. They loved it! If you want it instant, that is without the fuss of blending the fruits, Pei Sze shared that it could be eaten straight with any jam directly! I was rather surprised, but when I tried this with the blueberry jam, it tasted really great! Even SY loves it!
Here's the finished product from my 2nd attempt - my pictures are rather blurry because I took them with my PDA phone (my first attempt was not succesful because I added the yoghurt culture when the milk was still rather hot).
My finished product with my thermal cooker