FG too high?

[larkinnm1]

Hello all,

Bottled a pale ale today after 3 weeks in primary and the FG came in high at 1.020, from an OG of 1.050. Typical few days of good bubbling through the airlock, then dropped off. 9 lbs UK pale and 1 lb US Victory, with white labs California ale yeast. Any ideas on how my FG could finish up this high? Mash was at 150 and I calibrate my thermometer to freezing before every brew day, so my wort should have been very fermentable. I shake my carboy to aerate for 5 minutes before pitching. I did not use a starter, but with 1.050 OG I though I would have been ok. Unfortunately I did not measure gravity until it was already in my bottling bucket or I would have pitched some more yeast and waited.... Appreciate the input.

 

[michiganhomebrewer]

What temp did you ferment at?

 

[beardown2489]

Be careful. You may have created bombs.

What temp was it fermenting at? Was it constant?

Did you check gravity twice to be sure it was finished?

With beer of that OG, the yeast shouldn't have a problem with wort mashed at 150° unless you severely severally under pitched.

I'd store those in boxes and be very aware you could have bombs on your hands if for some reason the yeast decides to go back to work in a new environment.

 

[beardown2489]

Have you calibrated your thermometer? How certain of that 150 number are you?

 

[brew_ny]

hydrometer?

 

[larkinnm1]

Ferment in room set at 68. Highest temp I saw on my thermometer strapped to the carboy was 72. I place the thermometer in a ice bath before I brew, but have never actually needed to adjust. Hydrometer floats at 1 in water. Only checked fg once, in my bottling bucket. I will keep and eye on the bottle bombs. Thanks for replies

 

[ZebulonBrewer]

After three weeks it should almost certainly be done, especially that temp, which is perfect for WLP001. Could be a fluke, or you could have had a bad/stressed vial. You'll find out in a week or two I guess.

 

[Qhrumphf]

Depending on your thermometer, some of them (particularly inexpensive ones) have a very wide tolerance range (ie +/- 3 or 4 degrees, maybe even more), so what you thought was 150 could be 146 or 154, or even higher/lower than that. And it could still read perfectly accurately at both freezing AND boiling, and still be off in mash range. In other words the thermometer is ACCURATE but not PRECISE. It took me a while to figure that one out myself a few years ago before switching to a thermometer with a +/- 0.7 degree tolerance, and getting much more predictable fermentability as a result.

Just to confirm, you are reading the FG with a hydrometer, and NOT a refractometer, correct?

 

[larkinnm1]

Just to confirm, you are reading the FG with a hydrometer, and NOT a refractometer, correct?

Correct, measuring with a hydrometer. I didn't think to look at the package date on the yeast, so that could be it. before I had a glass thermometer, but broke it and bought one from my hbs. Maybe get a better one


Takes me to my next question. what to do when my fg is high when I measure it in the carboy rather than bottling bucket like an intelligent person? Shake the carboy to get it back in suspension, (possible oxidation after fermentation??), or raise the temp, or pitch some fresh yeasties??

 

[larkinnm1]

UOTE=Qhrumphf;6963885]

Just to confirm, you are reading the FG with a hydrometer, and NOT a refractometer, correct?[/QUOTE]

Correct, measuring with a hydrometer. I didn't think to look at the package date on the yeast, so that could be it. before I had a glass thermometer, but broke it and bought one from my hbs. Maybe get a better one


Takes me to my next question. what to do when my fg is high when I measure it in the carboy rather than bottling bucket like an intelligent person? Shake the carboy to get it back in suspension, (possible oxidation after fermentation??), or raise the temp, or pitch some fresh yeasties??

 

[Qhrumphf]

Yeah, if you were using old yeast with no starter, it could definitely underattenuate.

As far as fixing a stuck ferment, warming it a bit is possible, as is gentle rousing (I wouldn't shake it). Adding a small amount of simple sugar might get em hungry. Best solution is pitching new yeast via a small starter pitched at the very height of activity. Just dumping yeast straight into mostly-fermented beer isn't always a good idea, as it's not a particularly friendly environment and if they're not already going on a starter they could just drop to the bottom and quit right away. But dumping in a new pack straight could work too, just not as reliable as via a starter first.

 

[larkinnm1]

Update- beers turned out ok, a little sweet, so no bottle bombs. Sacrificed one to check fg and only saw a 1 point difference so looks like maybe I didn't pitch enough to complete fermentaion. I