I'm just starting the yogurt venture, it's all new to me.Not too bad. The back is owie, but that is normal. The shoulder isn't going to recover for a few months and, at the moment, the ligaments in both knees are doing a little screaming. So, situation "normal."
Wifey keeps a yogurt starter in the fridge, made from old yogurt (I think), and she puts the new batch in the oven with the oven light on as the only heat and it is yummy yogurt by the next day.