My third batch's ABV

[goodbyebluesky82]

I am brewing my 3rd batch (4th if you include cider), an Irish Sweet Stout.

My OG was 1.052, and after 4 days I am at 1.014.

If I do the math 1.052 - 1.014 * 131 I get 4.978% ABV

It was supposed to be 4.8% ABV according to the directions so I overshot it a little, and in only 4 days. Its still burping a little as well so its clearly not done.

Is it rare to overshoot FGs? Or was the directions/recipe just off?

 

[wildwest450]

It's not rare at all, what type of yeast were you using? Was your hydrometer adjusted for temperature?

 

[goodbyebluesky82]

Its nottingham yeast.

And wouldnt you know, I forgot to adjust for temperature on both hydrometer readings. But since posting, the foam has now subsided and now the FG appears to be a bit lower at 1.012

The correct gravities would be 1.053 - 1.013 * 131 = 5.24% ABV

EVEN HIGHER!

 

[TeleTwanger]

trying to get an accurate ABV within .1% is not gonna happen by using standard og/fg hydrometer readings and without knowing the exact volumes. It's just a close approximation at best just like IBUs, mash efficiency, volumes co2 for carbonation, color, etc; If you shooting for 6% and got 9% then I'd be concerned...Recipes aren't formulas and depending on the process(mash time/temps etc) they will have variable results.

 

[ifishsum]

Did the recipe call for Nottingham? I'd think a somewhat less attenuating yeast would be more suitable for a sweet stout, like Windsor or Safale S04

 

[goodbyebluesky82]

Yes it called for nottingham

 

[noremorse1]

Did you build up a starter? What temperature are you fermenting at? What means are you using to control your fermentation temperature?

Your yeast is probably in optimal conditions and working a bit better than the recipe anticipates under most circumstances. However, if you are fermenting at a high temperature, your yeast could be going nuts because of this. If this is the case, you are gonna get a lot of diacetyl and other off flavors.

 

[goodbyebluesky82]

No, no starter. Honestly I didn't even rehydrate it, just tossed it in and I had fermentation with 6 hours.

I keep my heat in the house at 72-74. The fermenter is in the corner of my kitchen and I closed the HVAC vent off in that room so that corner should be staying under 70 degrees. I think my fermentation temps have been pretty good.

I havent detected any diacetyl or off flavors in the hydrometer sample. For 5+% alcohol (according to calculations) it doesn't really show. Its smooth with mostly the roasted notes in the forefront, and very low in fruity esters.

 

[wildwest450]

Did you build up a starter?

Starters are not necessary with dry yeast.

 

[noremorse1]

Starters are not necessary with dry yeast.

Thanks... I am well aware of that. I didn't read down to the post where he said he used the Nottingham dry yeast.

If my memory serves me correctly, Nottingham yeast is really good at attenuating beer down pretty low.

 

[noremorse1]

I havent detected any diacetyl or off flavors in the hydrometer sample. For 5+% alcohol (according to calculations) it doesn't really show. Its smooth with mostly the roasted notes in the forefront, and very low in fruity esters.

70 is a decent temperature for fermentation and should not leave you with much diacetyl. I would leave your brew on the yeast for a few days after primary fermentation has stopped to let the yeast clean up the beer a bit though. If your outside temperature gauge (I am assuming you do not have a thermowell down the middle of your brew through the airlock here) reads 70, your inside temp is probably a few degrees higher as the yeast will bring up the temperature. However, sounds like all is well. Relax, have a homebrew!