Originally Posted by mike_d

I store grains in milk with a tight lid, then loosen the lid for fermentation.

Keep in mind milk used to store grains will ripen quicker -- usually in half the usual time. I try to stop mine before clear liquid (whey) begins to show at the bottom of the jar. Streaks usually form, visible thru the glass, just like when making yogurt as the milk begins to set up. It takes some experience.