How to re-start a stuck fermentation batch

[Brewsky]

First time post(er) here! I've brewed extract for years, and just recently brewed my first all-grain batch (a nut brown ale). Fermentation looked fine for the first three to four days, then stopped. Since then no bubbling or sign of activity in the wort I can't imagine that the SG is down to the desired endpoint. Any idea what may be going on, and how to re-start fermentation? Thanks!

[Ozwald]

It's hard to say without some data. It could be finished, or it could be stuck.

Some helpful things to know for us to help you figure it out:

OG
A current gravity reading
Mash schedule
Fermentation temp
Recipe info

[Brewsky]

OK. Thanks.

The original gravity (OG) was 1.053
Current specific gravity is 1.027 (3.4 % ABV)
The recipe target is 5.0 % ABV
Mash schedule was 1 hr, 35 minutes (60 minutes of mash and 35 minutes to sparge)
Fermentation temperature was ambient (warm with day one air temp of 104F)
Recipe information: More Beer Nut Brown Ale. 10 lbs British Pale, 0.5 lb Crystal 60L, 0.5 lb Caravienne, 0.25 lb Victory, and 0.25 lb Chocolate.

Hope this helps. I still detect no additional fermentation, so I'm not sure what to do short of pitching another vial of yeast (which I'm not even sure would help).

[barleyboy]

104° ambient air temp! Your done. Time to check with hydrometer.

[Ozwald]

Have you calibrated your hydrometer? If you put it in some distilled water (not tap) it should read 1.000 flat at the temperature the hydrometer is calibrated for. Usually when they're off it's only a few points, but still it's worth checking out. Also make sure you checked the temp of the beer when you did your gravity reading. It'll start reading off by just a few degrees away from the calibration temp (which should be printed on the paper in the stem of the hydrometer). And while we're on the subject, it's a good idea to make sure your thermometer is calibrated as well.

What temperature did you mash at? Which yeast did you use? Did you make a starter with it? The more info, the more helpful we can be.

As of right now with the info we have here, my first suggestion would be to rouse the yeast by gently swirling them back into suspension. Your fermentation sounds like it was significantly warmer than it should have been, but not enough to completely poop them out. Still they might have flocculated early due to the heat. You're likely to have some off flavors from it as well.

My second suggestion would be to add more yeast, but honestly with that warm of a ferment, I'd question if it's going to be worth the money. You really need to get that fermentation temp down to begin with. There's a number of ways to do it, from retrofitting an old fridge or freezer with a controller, to just putting some wet towels/old t-shirts on the fermenter & keeping a fan blowing on it. The better you can control the temp of your ferment, the better your beer will turn out. But if you can't afford to throw a lot of money at it right now, just keeping it cool is better than ambient at those temps.