Originally Posted by FredTheNuke
74 degree closet. Heat of fermentation brought the pail to 79.
Yep, that'd do it! It's too bad you can't keep it a bit cooler but that yeast strain will tolerate higher temperatures just fine. My preference, as far as flavor, is for it to be fermented in the 60s, but it won't be bad at higher temperatures just with more "flavors" to the wine.
You don't want to "lose" the grape juice, but you still have plenty left!