FG Fermenter vs Bottle

Discussion in 'General Brewing Discussions' started by Frankenbrewer, Jul 22, 2020.

  1. Frankenbrewer

    Frankenbrewer Well-Known Member

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    I have been thinking about this way too long. Anyway, here it is goes. Would your FG be lower once you have introduced priming sugar to the batch for bottling than the FG coming out of the fermenter? Does the trapping of the CO2 in the bottle affect the production of additional alcohol?

    I now leave this to the experts to opine on this. I shall thank you now and wait for the drama to unfold.
     
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  2. Bubba Wade

    Bubba Wade Well-Known Member

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    Without any detailed calculations, note that most recipes call for 5 oz. of priming sugar. The original amount of fermentable sugar in a 5 gallon batch pretty large by comparison.

    In theory, the FG would drop by a slight amount as the priming sugar is completely fermentable and would leave no heavier components in solution. However, given the ratio, I don't believe it would be noticeable.

    One thing to note is that your beer becomes heavier when you chill it. Chilling from 68°F to 39°F increases the specific gravity by 0.002.
     
  3. Nosybear

    Nosybear Well-Known Member

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    Bottle conditioning does exactly what a regular fermentation does: It consumes sugar, produces CO2 and alcohol. You're adding 2-3 gravity points to condition so the fermentation is so tiny there is, in practical terms, no change. In reality there is an increase in alcohol and some very tiny traces of fermentation products, neither are important practically.
     

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