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Author Topic: When to keg?  (Read 547 times)

Offline wrssqb

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When to keg?
« on: October 25, 2022, 01:20:38 pm »
I use Tilt hydrometers and SG is tracked in Brewfather. Every brew reaches the expected FG. However, there is still some slow fermentation activity for a few days to a week after reaching FG, resulting in a lower FG than anticipated, and thus a higher ABV. My usual process is to wait until there is no change in gravity for 2 or 3 days. I am not in a hurry to keg, and I don't have a reason to keg at FG. My beers are usually a few gravity points lower than anticipated, but I haven't been able to say that any have been too dry or have any other negative character due to the lower FG and higher ABV. This occurs with all of the yeasts that I use and all of the beer styles.

Example: I currently have a beer in a fermenter that has an expected FG of 1.011 which was reached on Friday, then was 1.010 on Saturday, 1.009 on Sunday, 1.008 on Monday, 1.007 today (Tuesday) and is slowing down. I anticipate that it will stop at 1.007 or 1.006.

Can I keg at FG, or should I wait until there is no change in gravity for several days to ensure that fermentation is complete, off-flavors have been cleaned up, the beer has dropped clear, etc.?

Offline denny

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Re: When to keg?
« Reply #1 on: October 25, 2022, 01:41:35 pm »
You can do either.  It's up to you.  Taste the beer and decide if it's ready.
Life begins at 60.....1.060, that is!

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Offline kramerog

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Re: When to keg?
« Reply #2 on: October 25, 2022, 02:29:52 pm »
Do not rely on expected FG; the yeast stops when it is ready not when a calculation says it is done. Expected FG is just a rough estimate that doesn't take into account how you brew and your brew system.

Offline MNWayne

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Re: When to keg?
« Reply #3 on: October 26, 2022, 05:05:34 pm »
Real FG is when the gravity stabilizes.
Far better to dare mighty things....

Offline wrssqb

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Re: When to keg?
« Reply #4 on: October 26, 2022, 05:19:10 pm »
Follow-up question then...

Are the attenuation percentages in Brewfather a conservative value, and real-world attenuation is typically more than Brewfather lists?

Should I average my actual attenuation for each yeast and update Brewfather accordingly to get closer to actual FGs?

Offline chumley

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Re: When to keg?
« Reply #5 on: October 26, 2022, 05:33:33 pm »
I think you should do less calculations and to relax, don't worry and have a homebrew.

Offline denny

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Re: When to keg?
« Reply #6 on: October 27, 2022, 08:14:48 am »
Follow-up question then...

Are the attenuation percentages in Brewfather a conservative value, and real-world attenuation is typically more than Brewfather lists?

Should I average my actual attenuation for each yeast and update Brewfather accordingly to get closer to actual FGs?

Attenuation ratings are simply a way of comparing one yeast to another and don't necessarily reflect the attenuation you can expect.
Life begins at 60.....1.060, that is!

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Offline Drewch

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Re: When to keg?
« Reply #7 on: October 27, 2022, 09:59:58 am »
Follow-up question then...

Are the attenuation percentages in Brewfather a conservative value, and real-world attenuation is typically more than Brewfather lists?

Should I average my actual attenuation for each yeast and update Brewfather accordingly to get closer to actual FGs?

I don't think Bf is intentionally conservative. It seems to use about the midpoint of the expected attention stated by the yeast lab updated with some estimates on the fermentability of your wort based on the mash profile. If you notice a predicted value is consistently off from your actuals, check through the model parameters and can probably find which one to tweak to correct for it.
The Other Drew

Home fermentations since 2019.

Offline kramerog

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Re: When to keg?
« Reply #8 on: October 27, 2022, 10:04:12 am »
Follow-up question then...

Are the attenuation percentages in Brewfather a conservative value, and real-world attenuation is typically more than Brewfather lists?

Should I average my actual attenuation for each yeast and update Brewfather accordingly to get closer to actual FGs?

You could try to update Brewfather so you get a better estimate of the FG for recipe formulation purposes, but I still would not rely on the expected FG for determining when fermentation is over.

Offline denny

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Re: When to keg?
« Reply #9 on: October 27, 2022, 10:21:49 am »
No software I've ever seen can accurately predict FG. There are too many variables.
Life begins at 60.....1.060, that is!

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Offline brewthru

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Re: When to keg?
« Reply #10 on: October 28, 2022, 06:19:01 pm »
If carbonating with CO2 really doesn't matter when you keg unless the beer is too old.