overcarbonated bottles

[Chefjp]

my bottles have been over carbonating!!!!!!! here is my process:

I wait for the fermentation to stop, usually in the 1.010 OG range, I do a cold crash at about 35°f for 2-3 days. I rack to a keg and force carbonate at 20 psi, for aprox 3 days. I then bottle with a blichmann gun.
the first weeks the beer is perfectly carbonated, but when they are over 4 weeks old, they are very very carbonated. obviusly they are continuing to ferment and carbonate in bottle.
is this normal? orshould I do something about it, like pasteurize?

Thanks

 

[TahoeRy]

Switch to conditioning with DME. Boil 1.25 cups of DME in a pint or two of water. Chill and add that to your keg (I've only done this with bottles). Problem is, it takes a whole lot longer to do it this way. I get good carbonation in about 2 weeks but three is perfect.

Your issue seems to be that you are kegging to soon. I'm just guessing, but it seems like its still fermenting after your force carbing and the two together are doing this. Maybe rack to a secondary for a week or two, then keg.

I don't bottle this way so I could be wrong. Just trying to help out and give you my $.02.

 

[Tinga]

how do you determine when your batches are done fermenting?

 

[Chefjp]

how do you determine when your batches are done fermenting?

FG reading

 

[Cyclman]

Ferm is done when FG is the same for > 3 days.

 

[TopherM]

Instead of 20 PSI for 3 days, put it closer to 12-14 PSI for 7-10 days. That's what I do, and carb always comes out right in the 2.4-2.6 atmosphere range. Perfect for most beer styles.

obviusly they are they are continuing to ferment and carbonate in bottle.

If you are at FG, and don't add any additional sugars, the beer scientifically CANNOT continue to carbonate.

Are you storing the bottles at room temp, or fridge temps? The only thing I can think of is that you are storing them at room temp, and a good bit of the CO2 can not stay dissolved in the beer at those temps, so it builds up in the headspace of the bottle. Then, you are putting them in the fridge when you want to drink, but you aren't leaving them at fridge temps long enough for the CO2 to dissolve back into the beer (takes about 48 hours at fridge temps). If that's the scenerio, and you opened a bottle, it would gush from the CO2 in the headspace violently disturbing the nucleation sites on the surface of the beer. It would be foamy when you opened it, which could easily be misconstrued for overcarbed, but if you actually took a look at the poured beer, it would be undercarbed.

That's my best guess.

 

[Chefjp]

Instead of 20 PSI for 3 days, put it closer to 12-14 PSI for 7-10 days. That's what I do, and carb always comes out right in the 2.4-2.6 atmosphere range. Perfect for most beer styles.

If you are at FG, and don't add any additional sugars, the beer scientifically CANNOT continue to carbonate.

Are you storing the bottles at room temp, or fridge temps? The only thing I can think of is that you are storing them at room temp, and a good bit of the CO2 can not stay dissolved in the beer at those temps, so it builds up in the headspace of the bottle. Then, you are putting them in the fridge when you want to drink, but you aren't leaving them at fridge temps long enough for the CO2 to dissolve back into the beer (takes about 48 hours at fridge temps). If that's the scenerio, and you opened a bottle, it would gush from the CO2 in the headspace violently disturbing the nucleation sites on the surface of the beer. It would be foamy when you opened it, which could easily be misconstrued for overcarbed, but if you actually took a look at the poured beer, it would be undercarbed.

That's my best guess.

How do you mesure the atmospheres?

 

[TopherM]

http://www.kegerators.com/carbonation-table.php