I make yogurt at home all the time and now want to expand to kefir making. Mainly for smoothies for breakfast or light dinner. I have been reading a lot about it and would like to get some good quality kefir grains. Is there a source you can recommend. Is yogourmet brand any good - it is what is available in my local wholefoods. Ideally, I would like to make enough for 2 glasses per day for DH and I. Any tips to make the kefir that tastes mild and not too tart?