Bottling after cold crash - Way over carbed

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lolcats

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Hi guys,

I know there are a few threads about this but couldn't find a definite answer.

I bottled a 1 gallon DIPA batch about 10 days ago and the beer is way over carbed, foam gushes out after opening and is almost only head after pouring it gently in a glass. I can just tell by the noise in makes when uncapping it that it is over carbed. No bombs though - put it straight in the fridge.

Anyway, trying to wonder why. Fermented for 3 weeks at 70F. Had steady hydrometer readings before bottling. Cold crashed 24 hours and bottled direcly after cold crash without warming it up. I used a basis of 25g of corn sugar per gallon and adjusted by weight so i think i used 85% of the sugar. So the amount was perfectly exact.

However, I've been reading different suggestions that cold crash sucks in extra co2 which could explain it's over carbed. What's your advice on this? I have a batch cold crashing right now and would like to bottle it tonight but it don't know how much corn sugar to use.

Thanks!
 
Either it wasn't done fermenting (what was the FG supposed to be and what did you read?) or an infection.

Cold crashing doesn't "suck in extra" it just allows the CO2 to be absorbed better.
 
I don't think it is from residual co2 but rather the extra beer density at cold temps. When you bottle warm and chill to fridge temps, the volume contracts about 2%. Starting cold doesn't at all.
 
Either it wasn't done fermenting (what was the FG supposed to be and what did you read?) or an infection.

Cold crashing doesn't "suck in extra" it just allows the CO2 to be absorbed better.

OG 1.080 FG 1.014. I was expecting something in that range. How could an infection change the co2 levels? I don't think it is the beer was delicious.

Maybe it allows the co2 to be absorbed better, but does that change the amount of priming sugar?

From Brewersfriend:
Temperature of Beer used for computing dissolved CO2:
The beer you are about to package already contains some CO2 since it is a naturally occurring byproduct of fermentation. The amount is temperature dependent. The temperature to enter is usually the fermentation temperature of the beer, but might also be the current temperature of the beer. If the fermentation temperature and the current beer temperature are the same life is simple.

However, if the beer was cold crashed, or put through a diacetyl rest, or the temperature changed for some other reason... you will need to use your judgment to decide which temperature is most representative. During cold crashing, some of the CO2 in the head space will go back into the beer. If you cold crashed for a very long time this may represent a significant increase in dissolved CO2. There is a lot of online debate about this and the internet is thin on concrete answers backed by research. We are open to improving the calculator so please let us know of any sources that clarify this point.

The equation this calculator uses to compute the amount of dissolved CO2:
CO2 In Beer = 3.0378 - (0.050062 * temp) + (0.00026555 * temp^2)



I don't think it is from residual co2 but rather the extra beer density at cold temps. When you bottle warm and chill to fridge temps, the volume contracts about 2%. Starting cold doesn't at all.

I'm not sure I understand.. Are you saying that cold beer will expand when warmed up? So that would explain that bottling cold beer increases pressure inside the bottle when back to room temp.

But shouldn't the pressure go back down once back to fridge after conditionning?

Makes sense, but are you sure it's just by 2%? I can't be the only one with this issue..
 
I think you are using too much sugar. 1 gallon/ 3.78 liters of beer at 2 volumes would be 16 grams of table sugar. And did you truly bottle 1 gallon of beer after trub loss? That would kick that sugar to beer ratio higher if you did not
 
I was aiming for 2.4

As i mentionned, i didn't add the full 25g (disolved into boiling water of course). I siphoned the beer to a separate container (onto 60% of the 25g of sugar which i put in that container before hand) weighed it, then added the top off prorated amounted of remaining sugar. Then stirred gently.

I'll try a basis of 22 or 23g of sugar in the next batch then
 
Hi guys,

I know there are a few threads about this but couldn't find a definite answer.

I bottled a 1 gallon DIPA batch about 10 days ago and the beer is way over carbed, foam gushes out after opening and is almost only head after pouring it gently in a glass. I can just tell by the noise in makes when uncapping it that it is over carbed. No bombs though - put it straight in the fridge.

Anyway, trying to wonder why. Fermented for 3 weeks at 70F. Had steady hydrometer readings before bottling. Cold crashed 24 hours and bottled direcly after cold crash without warming it up. I used a basis of 25g of corn sugar per gallon and adjusted by weight so i think i used 85% of the sugar. So the amount was perfectly exact.

However, I've been reading different suggestions that cold crash sucks in extra co2 which could explain it's over carbed. What's your advice on this? I have a batch cold crashing right now and would like to bottle it tonight but it don't know how much corn sugar to use.

Thanks!


What was the temp of the beer when you calculated your priming sugar? The Brewer's Friend app has a pretty good calculator and there are others out there as well. I use this one because I can take my mobile to my fermenting area where I weigh and add my priming sugar to the beer. Make sure you are calculating actual beer, not trub.

For example, a beer carbed at 2.3 volumes of CO2 would require 3.9 oz of dextrose @ 68F; however, the same beer bottled @ 40F only requires 2.3 oz of dextrose. Very easy to add too much sugar.

Cheers,
Dan
 
Well it was bottled cold so around 40F.

That is my whole dilemma.. In those priming calculator do you enter the average temp during fermentation or the bottling temp? Everyone seems to be giving different answers

Guess i'm just going to stop cold crashing..
 
I had gushers also after cold crashing. I found out that using BeerSmith to determining amount of sugar there is an adjustment for temp Since using that no more gushers. Was embarrassing as one gusher beer went into a contest.
 
I had gushers also after cold crashing. I found out that using BeerSmith to determining amount of sugar there is an adjustment for temp Since using that no more gushers. Was embarrassing as one gusher beer went into a contest.

Awesome! So what temp exactly do you imput?

Lets say it's at 40F in the fridge for 1 day after fermenting for 20 days at 70F
 
Awesome! So what temp exactly do you imput?

Lets say it's at 40F in the fridge for 1 day after fermenting for 20 days at 70F

You input the highest temperature the beer saw between fermentation and priming. This gives the calculator its baseline for how much yeast-produced CO2 stayed in solution. So in your case, 70°F.
 
Awesome! So what temp exactly do you imput?

Lets say it's at 40F in the fridge for 1 day after fermenting for 20 days at 70F

I just created a few temp's in BeerSmith and follow whatever it says. So far it's workid on the first bottling.
 
You input the highest temperature the beer saw between fermentation and priming. This gives the calculator its baseline for how much yeast-produced CO2 stayed in solution. So in your case, 70°F.

Some have stated this "the highest temp the beer saw" but BeerSmith says there is a differnce depending on the temp at bottling time. So I guess you need to try both and see what works for you. :mug:
 
When I used to bottle, I always used the highest temp it saw during fermentation when calculating the amount of priming sugar needed. When I used the temp at bottling, it was always under-carbed.
 
don't stop cold crashing. that's not the solution. or i guess it could be, but then you need to let the beer sit even longer in the primary until it all drops clear.

since i started cold-crashing, i started using the temp at bottle time. haven't had any gushers, and haven't noticed any under-carbonation. in fact, last night the wife and i compared a beer that was bottled on july 1st, to the same beer that was kegged on the same day. the kegged beer had lost quite a bit of pressure (i don't keep the gas on, because co2 is expensive here, so once i reach about 1/4 down, i just fill it up with enough gas to push the rest out). but the bottled beer had the perfect amount of carbonation. i didn't measure it precisely or anything, but it had a great head throughout drinking the pint.

so my suggestion is to go with bottling temp in the calculator. and as others have said, since you're dealing with such a small amount of beer here, your margin for error is incredibly low.
 
If you used your cold crash temperature to measure the priming sugar, it would be a bit undercarbed, not gushing. Very little CO2 actually gets "sucked" back in the beer. You know your finishing gravity, so here's the diagnostic procedure:

Pour a glass, let it foam and do its thing, and leave it alone for as long as it takes to go flat. You can also stir and/or pour from glass to glass to speed the process. Once it's flat, take a hydrometer reading. If it's lower than your FG, your yeast was either not finished fermenting, or you've got a wild yeast or bacteria in your brew. If the FG is the same, then you simply overprimed. No worries, it happens.

If the beer isn't infected (or if it is and still tastes alright), here's the next step to salvaging the batch:

Use a bottle opener to gently pry the crown cap just enough to slowly let CO2 start hissing out. Once the foam reaches the cap, release the bottle opener and use your capper to re-seat the cap. Repeat as necessary, but wait 4-8 hours between purges to let the CO2 leave the beer and enter the headspace. Make a mark somewhere on the bottle or the cap to indicate how many times you degassed. My infected "oozing" batch needed 6 degassings before it was at an acceptable level. If your bottles are forcefully gushing, you might need more. This is also done at room temperature. You *shouldn't* need to worry about bottle failure, since you're continually venting pressure, but you can still put the bottles in a big plastic tub, or a cooler to contain any shrapnel or beer if you have any doubts.

Also remember that it may have a bit of an acidic "bite" to the flavor that may or may not age out. This is due to the carbonic acid remaining in the beer from the high level of dissolved CO2 in the liquid.

I hope these procedures help you get to the bottom of what went wrong. It sucks when a batch goes against you, but it's great that you're questioning yourself and learning from your mistakes. Don't let a little thing deter you, cold crashing is a great tool, but ironing out the bugs is just part of the process. Brew on, brother!
 
If you used your cold crash temperature to measure the priming sugar, it would be a bit undercarbed, not gushing.

Yup. It's easy to remember once you understand the science behind it.

The priming sugar calculators ask for the beer's temperature because it allows them to consider the amount of CO2 already in solution. As we all know, cold beer holds more CO2 than warm beer. So if a beer finished fermenting and sat at 62° F, then there is some CO2 left in solution. Specifically, the last little bit of CO2 that the yeast produced as they finished up. If the beer were at 68° F, then there'd be less CO2 in solution, because warmer beer holds less CO2.

This is what the priming sugar calculators are assuming. You tell it whether the beer finished up at 62° or 68°, and it figures out how much CO2 must already be in solution. It then prescribes an amount of priming sugar necessary to add additional carbonation required to achieve the desired carbonation level.

The calculator doesn't know that you've cold-crashed the beer. When you tell it the beer is at 34° F, it figures, "Geez, that's pretty cold, there must already be a ton of CO2 in solution - you only need to add a little bit more sugar." But of course, your beer ISN'T already mostly carbed. As fermentation finished, your beer was pretty warm, and thus couldn't hold much CO2. As NatureOfTheYeast mentioned, as you cooled the beer, it didn't "suck back in" CO2 in order to remain saturated at the current temperature. But the priming sugar calculator doesn't know that. As a result, the priming sugar calculators are assuming that the beer already contains far more CO2 than it actually does, leading to undercarbed beer.

Use the warmest temperature the beer experienced after fermentation finished.
 
Yup. It's easy to remember once you understand the science behind it.

The priming sugar calculators ask for the beer's temperature because it allows them to consider the amount of CO2 already in solution. As we all know, cold beer holds more CO2 than warm beer. So if a beer finished fermenting and sat at 62° F, then there is some CO2 left in solution. Specifically, the last little bit of CO2 that the yeast produced as they finished up. If the beer were at 68° F, then there'd be less CO2 in solution, because warmer beer holds less CO2.

This is what the priming sugar calculators are assuming. You tell it whether the beer finished up at 62° or 68°, and it figures out how much CO2 must already be in solution. It then prescribes an amount of priming sugar necessary to add additional carbonation required to achieve the desired carbonation level.

The calculator doesn't know that you've cold-crashed the beer. When you tell it the beer is at 34° F, it figures, "Geez, that's pretty cold, there must already be a ton of CO2 in solution - you only need to add a little bit more sugar." But of course, your beer ISN'T already mostly carbed. As fermentation finished, your beer was pretty warm, and thus couldn't hold much CO2. As NatureOfTheYeast mentioned, as you cooled the beer, it didn't "suck back in" CO2 in order to remain saturated at the current temperature. But the priming sugar calculator doesn't know that. As a result, the priming sugar calculators are assuming that the beer already contains far more CO2 than it actually does, leading to undercarbed beer.

Use the warmest temperature the beer experienced after fermentation finished.

THANK YOU. Best explanation.

:rockin:
 
Thanks for everyone's great advice.

I bottled my citra/chinook IPA (tastes like tropical juice) last night using less sugar 22g/gallon basis instead of 25. Will see how it turns out! Was about 55F when bottling and crystal clear amber color. Used a 70F basis for the priming calculation.
 
Here are some numbers from BeerSmith using table sugar, in a 1.8 gallon bottling volume shooting at a carb level of 3 volumes for a Blonde Ale
Default setting -------------------1.9 oz
BottlingTemp = 46 --------------1.5 oz
BottlingTemp = 40 --------------1.35 oz
 
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