I recently started 4 batches of cider (in corny kegs). It's half Whole Foods juice and half real cider with no preservatives other than the Vitamin C in the WF stuff. 2 kegs have champagne yeast, one has saison yeast, and the other has Mangrove Jack yeast. Each got yeast nutrient and 2 of the kegs got a custom herb and/or spice tea added to them. I wanted to do a slower ferment than normal so I turned the basement temp down to 65. After a couple days, there was occasional bubbling from the blowoff tubes. I expected it to pick up but it really hasn't. They've been fermenting for 6 days and I only hear one bubble (from all the kegs combined) every few minutes. I checked for leaks at posts/lid and that doesn't seem to be the issue. I measured the temp at the floor and it says 63. I'm probably going to raise the temp to get things moving a little faster. I'm primarily concerned with the oxygenated cider (from pouring into the corny's) going bad because the yeast aren't moving along fast enough and consuming the oxygen. Should I be concerned with this? How often should I be hearing bubbles from each keg at this point if I'm looking for a slow fermentation (but without oxidation issues)?