[DEEPIKA]

Could anyone tell me the chemical equations involved in the formation of yogurt from dairy milk and soymilk ? Why are specific temperatures required for this?

[lancenti]

You may want to run through Google or Wikipedia at the very least.

You'll find that Yoghurt isn't just one compound but many, hence the best equation you'll get would probably be:

Milk + Bacteria -> Yoghurt

Since you're dealing with living organisms, the answer to the specific temperature might be more obvious. You'll also want to consider how temperature affects enzyme action.