Sondra, I was thinking of you when I posted

Check your kefir after the three days by shaking it up good and just straining off a little. If it is not as thick as you want go ahead and give it more time.
I stumbled onto this accidentally when we were slower than usual going through our kefir. The Kefir had been sitting in milk in the fridge for a week or more. When I strained it I had too press it through with a spatula. I was surprised that it did not get tart, it tastes very good. So I tried to do it again on purpose and so far it works every time.
It is really good with a tablespoon of frozen juice concentrate like white grape and peach. No kidding, it is better than yogurt!
Christy