Fermentation stopped early - AVB too low

Hi!

I brewed my first batch of beer a week and a half ago (American Pale Ale). Brewing in Florida, I had difficulty maintaining temperature during fermentation. After 4 days my brew stopped bubbling and on average was about 82 degrees F. I've read that temp. will speed fermentation so I wasn't worried and I decided to let it sit the rest of the 2 week period anyway. With bottling day approaching I decided to take a hydrometer reading and found the temp. corrected AVB to only be at about 3.5% What should I do? Pitch some more yeast, swirl and leave for another week or so? If so how much yeast should I use, otherwise what are my best options?

Thanks In Advance

That seems awful warm for Fermenting, I've just started myself, I could be wrong. I am fermenting a American Pale Ale now and am trying to maintain 65 degrees with a swamp cooler set up

What was your OG and FG? How did you calculate your ABV? You didn't read ABV off the hydrometer, did you, because that scale is for wine, not beer.

At 82, you almost certainly didn't have a stalled fermentation, and there is about a 99% chance you are at FG, so I bet you had a low OG to begin with, if that ABV calculation is accurate. Probably topped off with too much water pre-fermentation.

List your OG and FG, along with a bit of info about your process, and I'm sure we can find the culprit here, but it doesn't sound like any problems with the fermentation itself.

I may be experiencing a similar problem with a batch of brown ale I recently brewed up. My original gravity was 1.052 when I pitched the yeast. I rehydrated the yeast before pitching it into my wort. Within 6 hours I was getting a bubble out of my airlock every 3 seconds. After 24 hours the airlock literally looked like it was boiling with a bubble or two a second. My airlock stopped bubbling altogether after about 4 days. A week after brewing I racked it to a Carboy and checked the gravity again. This reading was 1.026.
The fermenter was between around 70-74 degrees throughout this time.


OG- 1.052
FG- 1.026

I am going let it sit in the Carboy for a week or so before bottling. Do these numbers sound right or did my fermentation stop a little premature.

Not sure if I should repurchase some more yeast, sure seems like there is a substantial amount of sugar still in the wort.

Thanks

After a week, yeah. Some beers finish soon, some don't. Depends on the fermentables present, the yeast, how happy the yeast was, etc. I don't know if I would have racked to secondary unless the gravity had slowed wayyyy down. That requires a few days of readings.

A decent rule of thumb for MOST typical yeast strains in a typical gravity brews is that you will get about 75% attenuation. That means you would expect a 1.052 OG brew to end at about 1.013 FG (52 x .25 = 13). It is also pretty unusual for anything other than higher gravity beers to get stuck fermentations.

Remember that just because the airlock is done bubbling doesn't mean fermentation is complete. Only hydrometer readings can show when fermentation is complete. I've had many many brews where the last 10-15% of fermentation didn't show a blip on the airlock. It's done when it's done.

TopherM
Should I repitch some more yeast into the carboy? Is this batch still salvageable?

Thanks for the tip about not relying on airlock alone to gauge when fermentation has ceased. Still new to home brewing, lesson learned!

Stones said:

TopherM
Should I repitch some more yeast into the carboy? Is this batch still salvageable?

Thanks for the tip about not relying on airlock alone to gauge when fermentation has ceased. Still new to home brewing, lesson learned!

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Just let it sit around room temp in the carboy (68-70 or so) and give it a week, then take gravity. There's still yeast in there. Let it do it's job, no matter how slow it goes.

Yeah, if you are only a week or so out, there is plenty of time to just let the yeast do their thing. I'd put it in an interior closet at room temp, give it a slight swirl to rouse the yeast, let it sit for another week or two, then take a new gravity reading.

@rmaloney86 – I picked the week Tropical Storm Debbie decided to grace my town with its presence. Multiple power outages etc. made regulating temperature impossible; I agree I’m way on the warm side but still hoping to salvage my first, ill-timed brew.

@TopherM – OG=1.05, FG= 1.01. The difference multiplied by 131.25 for an AVB of 5.25%. Then I realized the temp (82 degrees) and used a temperature correction calculator found here (http://www.copper-alembic.com/distillation_table.php?lang=en&strongi=5.25&tempi=28) which gave me 3.5% as my corrected. When I finished cooling the wort I poured it in to a Brewer’s Best plastic primary fermenter bucket. I added enough water to bring the total volume up to the 5 gallon mark on the bucket. In retrospect I should have written down how much water that was. Or read the hydrometer to the next decimal place when taking the OG. Does it sound consistent with what you thought, too much water added pre-bucketing?

So that table looks like a correction for an alcoholometer for distilled liquor. No experience with that whatsoever, but don't use that. Your hydrometer should come with a correction scale for temperature, probably something like add .003 when measuring at 82 deg. So your OG would be 1.053 if measured at 82 deg, and your FG 1.013 if measured at the same temp, giving same ABV of about 5.25%.

Oh, sweet! I saw alcoholometer on that website but thought it was just another name for a hydrometer and missed the distilled liquor part. Like a lot of other people, I was sure I ruined my first batch Now I'm back on track to bottle on Sunday, WoOt! I'll find the temp. correction chart on the hydrometer and use that from now on. Thanks again!

Both OG and FG were taken at 82* beer temp?

A point to remember.. when you are adding topping water.. if it isn't really mixed well with the rest of the wort, you will have stratification.. heavy wort stays at the bottom and the water toward the top. If you take the reading from the top of the FV.. you'll almost certainly be off a bit/bunch. I'd suggest stirring well with a sanitized spoon before taking the OG reading. If you are going to fill to the 5G mark you are going to be consistent for your brews and that part is good. That consistency should allow you to add/subtract fermentable to hit your target OG.

Also, using a sanitized airstone and pump will do a good job of aerating (and mixing) your wort before pitching the yeast and taking that OG reading.

Just a thought.

CupForAKing said:

@rmaloney86 – I picked the week Tropical Storm Debbie decided to grace my town with its presence. Multiple power outages etc. made regulating temperature impossible; I agree I’m way on the warm side but still hoping to salvage my first, ill-timed brew.

@TopherM – OG=1.05, FG= 1.01. The difference multiplied by 131.25 for an AVB of 5.25%. Then I realized the temp (82 degrees) and used a temperature correction calculator found here (http://www.copper-alembic.com/distillation_table.php?lang=en&strongi=5.25&tempi=28) which gave me 3.5% as my corrected. When I finished cooling the wort I poured it in to a Brewer’s Best plastic primary fermenter bucket. I added enough water to bring the total volume up to the 5 gallon mark on the bucket. In retrospect I should have written down how much water that was. Or read the hydrometer to the next decimal place when taking the OG. Does it sound consistent with what you thought, too much water added pre-bucketing?

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1.010 FG is a pretty good result. If you get that 2 days in a row you can be sure it is done. You should also read to the thousandths.