Hello, I've been noticing different results when I make "yogurt" with or without a sealed lid (I've been only making kefir and clabbered raw milk so I don't know if this effect is applicable for other types).
Specifically, the milk tends to curdle when I leave the lid off (just cloth cover) with more air circulation. If I have the container sealed with a tight lid, the milk sours quicker but remains liquid.
Is this a result of different bacteria being encouraged with/without air availability? If so, does anyone know what are the possible bacteria strains at action here? Or, does it have to do with simply some chemical reaction between the milk itself and the presence of air?
I've been puzzled about this phenomena for quite some time and haven't been able to find a convincing answer yet.
