Sliced open a wheel of waxed Sage Derby made 9/21, because in the last couple days I noticed it was seeming to bulge (well, I was planning on opening it soon anyway). It had been stored on its side on a fridge shelf, no cradle. As you can see, there is a large crack running through it. So my thought was the "late blowing," and I should throw it out.
But I also wondered if it was just due to the storage method. 1) storing it on its side would put pressure and might make it "give" in exactly this manner. 2) I do not have a good press (I just pile weights on a frame, but don't have a lever system), so my cheddar types haven't yet consolidated well (the milled curds remain somewhat separate even after pressing and aging), so again this would be a weak point when storing on its side. 3) salted curd types like cheddar and derby are supposed to be the least likely to get clostridium type blowing. 4) while the introduction of the sage seems like that could be the culprit (from say a bit of dirt on the leaves), I did wash and boil the leaves first. 5) I don't smell (or taste--I chewed some and spit it out) any off flavors that are supposed to come with butyric and acetic acid.
I'll throw it out just to be sure. But wondering if others think it might not be blowing after all.