Hi, I've been making kefir for about a year, and I recently moved, bringing my kefir with me. however, lately my kefir hasn't been separating, creating that bubble or pocket in the milk. I use 2% milk and keep it in a dry, romm temperature cupboard above my refrigerator. I like my kefir reaaly sour, and usually leave it in milk for 4-5 days. I've tried putting half as much milk as i usually do (at least 1 litre), but there is no change. the grains still change the milk, but it never gets as thick or as sour as it used to, and it never separates the milk, making that bubble. Does anyone have any suggestions about why it doesn't do this anymore or about how to restart it?