I have one of my iSpindels in a Maibock that is close to being fermented out. I just raised it up to 67 for a diacetyl rest. The first 75% of fermentation was relatively normal (it took off because it was an active yeast cake from a previous beer). The last couple of days, though, the SG has been all over the place. Obviously, I'll take a hydrometer reading when it is done for an accurate number, but I haven't seen this iSpindel behavior before. Does anybody have any idea what is happening here?