FG Question

[dierythmus]

I recently brewed an imperial pumpkin ale (5 gallons) that had an OG of 1.084. All went well during fermentation (used 2 packets of US-04 in fermentation chamber for 3 weeks, very active throughout).

I kegged, but forgot to take a FG reading. I decided to try to take a FG reading of the flat beer (I left it out overnight). My FG was 1.017. I'm not upset with this, but this is by far the highest FG I've ever had. I typically get most of my beers within the 1.009-1.011 range. The beer tastes fine, btw.

I did add a teaspoon or two of pumpkin pie spice and 2 oz of vanilla extract at time of kegging. Would that (or the gelatin finings) have any impact on the FG if I measured out of the keg?

 

[ACbrewer]

The rule of thumb is 75%... so if you started with a OG of 1.084, you'd finish about 1.021 Now there are something about this as a rule of thumb, each yeast finishes differently. The yeast manufacturers publish what the Attenuation is - 75% is typical, but it can be as low as 65% and as high as 85% when fermenting 100% malt. Anything not malt (corn sugar, honey, etc) has the potential for different numbers. In the case of sugar and honey, it is 100%.

Anyhow, if I had to guess, I'd say that you had some sugar in your initial, which accounts for the lower gravity than I would have guessed. But I've not checked your specific yeast for it's attenuation.

 

[BrewerBrad82]

That is just shy of 80% apparent attenuation, I would say everything sounds perfectly fine to me as S-04 is usually right around 75% apparent attenuation in my experience. Pumpkin pie spice, vanilla extract or gelatin will really have no effect on the FG. If it tastes good, roll with it!!

 

[Cyclman]

Bigger beers typically equate to higher FGs, unless sugar or the like is added to really dry them out. For a pumpkin with that much alcohol, it will be fine.