Has anyone tried using Brett to dry out a stuck fermentation?
The back story: I was brewing a Hef (OG 1.054, IBU 15) while savoring my new, amazingly tasty, pear Saison. Strangely enough I had some thermometer / temperature control issues (>160F) during the mash, possible caramelization from a direct heat mash, plus a grain bill with a decent amount of specialty malt. Essentially a recipe for poorly fermentable wort.
I pitched with WL300 Hef yeast (two tubes just to be sure) but, not surprisingly, fermentation stopped abruptly after 36 hr leaving me an FG of 1.021, or 60% attenuation rather than the 1.013, 75% I was shooting for. (aeration may also have been low) The taste test reveals that this beer is not good. At 1.021 it could be vaguely passable as the fourth or fifth beer of the night, but I'd rather try to fix it than drink as is. I tried heating, swirling and hoping, but the fermentation didn't restart.
So what to do? A buddy suggested that I try repitching with a high-attenuation strain of Brett to dry it out. I had my eye on WL645, which promises to add little flavor and (if done right) an aroma of tropical fruit that might go well with the banana hef esters. Is this crazy talk? Will a Brett yeast such as WL645 really take 5-10 points of gravity out of a non-fermentable wort like this? Any other yeast ideas or otherwise?
Thanks in advance!