Do I culture milk kefir with a lid or with cheesecloth?

I always culture my kefir with a lid on. I use a one-quart glass canning jar with a plastic lid, but a metal lid is also fine as well. Many people have trouble when they use a cloth and rubber band due to wild yeast or cross contamination from other cultures. They can get a fuzzy pink yeast on their grains, and although this isn’t harmful it can can change the taste of your kefir, so I always recommend a lid.