Ask MeCha: buttermilk. →[More:]
So I made some butter the other day (which was very fun and delicious) and the buttermilk I ended up with was VASTLY different from store-bought stuff. This was blue-ish, very sweet and light, with little grains of butter in it. The stuff from the store is kind of sour and curdy, in a pleasant way.
What gives? Why are they so different?