Okay: I diluted ridiculously strong (almost syrup) maple sap down to
1.140 SG, added some primed yeast, a bit of yeast nutrient (according to instructions on the container) and things started fermenting. Because the sap was so thick, and I had so much of it, I wound up putting about 20 L of must in a primary, and another 20 L or so in a carboy with lots of head room. Put both next to a oil-filled room heater, so they both are at about 20 degrees Celsius.
This was about eight days ago.
The second or third day after re-starting the maple wine at 1.140 SG, the fermentation was obvious: a yeasty foam was forming on the surface. I'd stir once a day to keep a bit of oxygen in the mix.
Both are still fermenting (I put an airlock on the carboy this morning, just as an experiment), but starting three days ago, on top of both musts there is a thick layer of ... slime. It's the only way I can describe it. It' sort of a rich brown foam on the top, but when I put the stirring spoon in, it goes through a few millimetres of a viscous clear (beige, translucent, not opaque) goo that has the same texture and consistency as what I imagine frog eggs are like. If I stir, it sort of clings to the spoon and "balls up" in the centre on top of of the must, but its natural elasticity spread it right back out again.
It's... uh... gross. But is it bad? Harmful? I've never seen anything like it before, but a quick check of SG showed a drop down to about
1.120, and a quick taste of the sample (taken from sub-slime levels) showed it to be tasty, if somewhat syrupy/slimy. And with a bit of evident alcohol kick already.
What's the slime? Should I be worried?