On Monday 06 Oct 2008 7:27:47 am Deepa Mohan wrote: > How does that explain the setting of yogurt with culture, which is done > with a spoon and never by hand? I *do* have the problem; my neighbour sets > her yogurt in the morning, I find it difficult to get it to set even > overnight. I have tried using her yogurt culture, using the exact same > process and amount and so on.
It's the temperature Deepa. Yogurt and idlis are different. The fermentation of idli mix, which makes idlis fluffy, is caused by different bugs - maybe yeast - would have to ask CFTRI. Yogurt is Lactobacillus bulgaricus and L.stearothermophilus IIRC (willing to be corrected - haven't looked at Google uncle about this) - i.e they are pure bacteria that need to be inocluated into milk and incubated. The best (sweet , not sour) yogurt is made with milk pre-warmed to about body temperature (or slightly higher) and cultured in the morning and put in the fridge as soon as it sets - i.e within 3 to 5 hours. "Overnight" is no good for this. If the ambient temperature is high the yogurt sets faster and sours faster if not put in the fridge. Idli mix on the other hand is fine "ovenight" and the best idli mix overflows out of the container from fermentation even without pre-warming, and the mix needs vigorous stirring to break up the froth and "contract" the mix back into the container. But this is at Indian ambient temperatures. In the UK idly mix had to be put in those quaint "airing cupboards" that UK homes used to have. shiv
