Partially carbonated beer coming out of my primary

[kdbentz]

From time to time when I go to rack my beer from my primary plastic bucket to a secondary carboy, the beer is already carbonated.....to varying degrees depending on the batch.......Anyone have any idea what the reasoning would be for that?

 

[TheMadKing]

From time to time when I go to rack my beer from my primary plastic bucket to a secondary carboy, the beer is already carbonated.....to varying degrees depending on the batch.......Anyone have any idea what the reasoning would be for that?

That's totally normal and just from the yeast activity during fermentation. You bubbling airlock was CO2 that while time, so some of it was bound to stay in the liquid.

 

[jc5066]

CO2 is a byproduct of fermentation. When you add priming sugar prior to bottling what you are really doing is restarting fermentation. That's one way to carbonate bottled beer.

 

[kdbentz]

Ya just curious why it would stay in solution in the primary.....seems like if its not under pressure (like in a bottle or keg) that the co2 should escape.....but some apparently stays in it.....weird

 

[jc5066]

It takes a bit for all CO2 to escape. If it was still fermenting, even a little, it will keep producing CO2

 

[k-moe]

Ya just curious why it would stay in solution in the primary.....seems like if its not under pressure (like in a bottle or keg) that the co2 should escape.....but some apparently stays in it.....weird

Some CO2 gets dissolved into the beer during fermentation. Gases are solubile in water (and other liquids), which is also why fish are able to use the dissolved oxygen in water to breathe (the oxygen atoms that are part of the water molecule are bound, and not available for respiration).
When you look at a carbing table the amount of sugar needed is based on the current amount of dissolved CO2 at the temperature the beer was last at in order to keep from overcarbing the beer.

 

[day_trippr]

The carbonation level resulting from a typical ale fermentation is not insignificant.
If a beer finishes fermentation at, say, 65°F, there'll be roughly .75 volumes of CO2 extant...

Cheers!

 

[psymonkey]

I just had this while racking a Belgian Quad from the secondary to the keg. I've been brewing for a good while now, and have never had the beer I pulled for my hydrometer have two inches of foam on it! I've seen some mystery carbonation before, but never like this. Guess it's going to take a lot less C02 to get this ready to serve!! Glad it's fairly normal.