Huh, did not know that it would kill the lactose.
Does the piima stay somewhat liquid when cultured overnight? I've seen that it's supposed to be a drinkable yogurt. I would prefer not to have to dilute it with fresh milk to make the smoothie, I suppose I could use water though if needed to dilute some.
When I was looking at cultures online one said to check it after about 9 hours and if not done it could go up to another 36 hours, so I figured that if I treated it somewhat like a sourdough and got the bulk of it out of the jar to make my smoothie, then added more milk to the bit that was still in there (feeding it) and let it sit until next smoothie time, of course if it was going to have to wait more than 24 hours between removing the yogurt I would put it in the fridge to slow the little culture beasts down some.