# When do bottle bombs happen?

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#### L0stm4n

##### Active Member
I bottled a cream ale this past Saturday. I had been using an online calculator to figure how much priming sugar to add. My past two batches have come out a bit flat so I decided to add a bit more sugar than the calculator suggested. It suggested 2.8oz of cane sugar for 5 gallons. We ended up with about 5.5 gallons and I added 4oz of sugar. When we finished bottling we tasted a little bit that was left over. It was very sweet. We put the bottles in some plastic storage containers incase they blew up. I haven't heard anything blow up yet. How long after bottling would you think until you are out of the woods?

#### BigB

##### Well-Known Member
2.8 ozs is very light for 5 gallons of cream ale (style is 2.6-2.7 volumes of C02). I bet it was kind of flat. Even 4 ozs of dextrose for 5 gallons will only yield about 2.4 volumes. You are fine! Try this calculator instead: http://www.tastybrew.com/calculators/priming.html

As a rule of thumb you could use 3/4 cup of dextrose (corn sugar) for priming most styles.

EDIT: I bet you confused the 2.8 for ozs instead of volumes. Two completely different concepts. 2.8 volumes of co2 would be fine for a cream ale. But to get 2.8 volumes of co2 you would need to use approximately 5 ozs of sugar.

#### jsweet

##### Well-Known Member
I'm sort of interested in the OP's original question, i.e. is there an amount of time after which if you were going to get a bottle bomb it probably would have happened already, or is it indefinite?

OP

#### L0stm4n

##### Active Member
2.8 ozs is very light for 5 gallons of cream ale (style is 2.6-2.7 volumes of C02). I bet it was kind of flat. Even 4 ozs of dextrose for 5 gallons will only yield about 2.4 volumes. You are fine! Try this calculator instead: http://www.tastybrew.com/calculators/priming.html

As a rule of thumb you could use 3/4 cup of dextrose (corn sugar) for priming most styles.
Sorry I should have specified. I was using normal table sugar measured on a digital scale. That is the calculator I used. I think we bottled when the beer was 36 degrees or so. I cold crashed it down before bottling.

#### o4_srt

##### Well-Known Member
jsweet said:
I'm sort of interested in the OP's original question, i.e. is there an amount of time after which if you were going to get a bottle bomb it probably would have happened already, or is it indefinite?
I'd say within 2 months, depending on style, but that's just a guess

#### kansasbrew

##### Well-Known Member
Here is something I wonder. Did you get the sugar mixed well throughout the five gallons. I find that there is sometimes a lingering amount of sugar at the bottom which makes the last dregs seem too sweet. So maybe the danger is in those last few bottles and not the whole batch. It might be interesting to pop the top on one of the first bottles to see if it tastes different.

#### cox8611

##### Well-Known Member
I have had issues with bottle bombs, but only if i bottle and the beer is cold (say 30-50*F), and if it has not been given enough time to attenuate ALL the way down. racking to bottle too early could leave residual sugars that haven't not been chewed up could lead to overcarbing and potentially bursting. And even after all that the beer would have to warm up enough to eat the residual sugars (~80*F) that weren't chewed up to begin with.

there is a certain amount of CO2 dissolved in the beer if you bottle it cold which could cause you to overprime it by mistake.

OP

#### L0stm4n

##### Active Member
Here is something I wonder. Did you get the sugar mixed well throughout the five gallons. I find that there is sometimes a lingering amount of sugar at the bottom which makes the last dregs seem too sweet. So maybe the danger is in those last few bottles and not the whole batch. It might be interesting to pop the top on one of the first bottles to see if it tastes different.
The sugar should have been mixed pretty well. I boiled the 4oz of table sugar for about 5 minutes with approximately a cup and a half of water (eyeballed). I then dumped that right into the bottling bucket and siphoned the beer on top of it. Once that was complete I gave it a few good stirs with a sanitized spoon making sure to make motions from the bottom to the top but avoiding aerating the beer.

FG before adding sugar was 1.004, OG was 1.050.

#### BigB

##### Well-Known Member
Sorry I should have specified. I was using normal table sugar measured on a digital scale. That is the calculator I used. I think we bottled when the beer was 36 degrees or so. I cold crashed it down before bottling.
Something else to think about here... When you cold crash the beer, the yeast drop out of suspension. No to little yeast mean no to little carbonation. When bottling, your beer should be close to or at room temperature and remain there for a couple weeks until the beers are fully carbonated. Ignore that temperature adjustment on tastybrew. If you cold crash your beer in an unsealed environment, the co2 will not magically dissolve into solution unless there is pressure. The CO2 that was left in the beer immediately prior to cold crashing is about all you will have left.

#### o4_srt

##### Well-Known Member
When you bottle cold beer, you must account for residual co2 that is in the beer. Cold beer holds more co2 than warm beer.

That's why calculators ask for beer temp: to factor the residual co2 into the equation.

You'll find that warm beer requires more sugar than cold beer, for a given volume.

OP

#### L0stm4n

##### Active Member
Something else to think about here... When you cold crash the beer, the yeast drop out of suspension. No to little yeast mean no to little carbonation. When bottling, your beer should be close to or at room temperature and remain there for a couple weeks until the beers are fully carbonated. Ignore that temperature adjustment on tastybrew. If you cold crash your beer in an unsealed environment, the co2 will not magically dissolve into solution unless there is pressure. The CO2 that was left in the beer immediately prior to cold crashing is about all you will have left.
That was just this batch. My previous batches all stayed at fermentation temp around 64F up to bottle time. After bottling they were at basement temp (68-70). This was the last batch in my fermentation fridge and I needed the freezer portion to store some stuff. Figured I'd just leave the beer in there and let it cool.

#### SauceBoss

##### Well-Known Member
As a rule of thumb you could use 3/4 cup of dextrose (corn sugar) for priming most styles.
This is what I do with 1 - 2 cups of water and havent had any problems.

#### Kealia

##### Well-Known Member
When you bottle cold beer, you must account for residual co2 that is in the beer. Cold beer holds more co2 than warm beer.

That's why calculators ask for beer temp: to factor the residual co2 into the equation.

You'll find that warm beer requires more sugar than cold beer, for a given volume.
True, but correct me if I am wrong - that only matters if you are fermenting at colder temps. The CO2 that gets absorbed into the beer is done during fermentation. by fermenting at 'normal' temps and then cold crashing you are not adding any more CO2 into the beer than was already there when it was fermenting.

Example: If I ferment a batch at 65, I have X amount of residual CO2 in the beer. I bottle as normal using the online calculator at Tasty Brew inputting the ferment temp for BEER TEMP.
If I ferment at 65 and then cold crash for a week at 40 degrees I still use the same 65 input on the calculator because THAT is what determined the amount of CO2 in my beer.

#### o4_srt

##### Well-Known Member
Kealia said:
True, but correct me if I am wrong - that only matters if you are fermenting at colder temps. The CO2 that gets absorbed into the beer is done during fermentation. by fermenting at 'normal' temps and then cold crashing you are not adding any more CO2 into the beer than was already there when it was fermenting.

Example: If I ferment a batch at 65, I have X amount of residual CO2 in the beer. I bottle as normal using the online calculator at Tasty Brew inputting the ferment temp for BEER TEMP.
If I ferment at 65 and then cold crash for a week at 40 degrees I still use the same 65 input on the calculator because THAT is what determined the amount of CO2 in my beer.

there is co2 in the headspace of the Carboy. Couldn't that be dissolved back into solution upon cold conditioning?

#### sillyburt

##### Well-Known Member
I'm a relative newbie but I do have 30 batches under my belt....so my advice/opinion is worth what you've paid for it

I've read about this before and have heard the arguement about wether or not when cold crashing down to lower temps from upper temps puts more CO2 into solution.

recently (~10 batches ago) I started cold crashing. I adjusted my sugar for the lower temp and felt (with my limited taste3 buds) the beer was under carbed. the past few batches I've used sugar based on the highest temp I ever had it at (4-5 oz per 5.5 gal batch). I've had no bottle bombs since about the p[ast 2-3 months.

also I don't believe that CO2 can be forced back into solution. sure it happens after bottling but that's aFTER INTRODUCING MORE SUGAR AND (damn caps) selaing the vessel. when you cold crash the vessel isn't sealed if there's still an air lock on it so I can't see the CO2 in the headspace being 'forced' into soluciton. in fact I see the air lock taking air into the carboy and that does have me worried at times :-s

I'd also like to know if there is a certain time limit that you're out of the woods on bottle bombs. I also put my bottles in a plastic rubber maid tub for 2-3 weeks at room temp to carb up before mov ing to basement. I figure it's the safest that way.

#### Yooper

##### Ale's What Cures You!
Staff member
Mod
True, but correct me if I am wrong - that only matters if you are fermenting at colder temps. The CO2 that gets absorbed into the beer is done during fermentation. by fermenting at 'normal' temps and then cold crashing you are not adding any more CO2 into the beer than was already there when it was fermenting.

Example: If I ferment a batch at 65, I have X amount of residual CO2 in the beer. I bottle as normal using the online calculator at Tasty Brew inputting the ferment temp for BEER TEMP.
If I ferment at 65 and then cold crash for a week at 40 degrees I still use the same 65 input on the calculator because THAT is what determined the amount of CO2 in my beer.

Correct. More co2 doesn't magically appear during cold conditioning. Use the highest temperature the beer was at prior to cold crashing. That is more accurate.

Or, instead of using priming calculators to begin with (faulty, with temperature/styles) just plan on 1 ounce of priming sugar per gallon max for most styles. I like 4 ounces for 4.5-5 gallons of American ales.

#### Kealia

##### Well-Known Member
I'd also like to know if there is a certain time limit that you're out of the woods on bottle bombs. I also put my bottles in a plastic rubber maid tub for 2-3 weeks at room temp to carb up before mov ing to basement. I figure it's the safest that way.
I dunno. The 4 bottle bombs that I ever had were after they were sitting for 3 months or so at 65 degrees. Go figure. I hadn't checked on them in about 3 weeks so they happened during that period of time. They didn't happen all at once (I assume) because they were in different cases, were different brews/batches/styles, etc.

So...I have no clue when you're free and clear.