I was making my milk kefir in quart mason jars which was just right for my heaping tablespoon of plump grains, but the last week I've used a pint mason jar which makes thick creamy tangy kefir for me in four days. When it begins to separate I know it's time to harvest them. I am drinking on average, about a half cup to a cup a day, but even that seems too much although I love it.