Bottle Bomb Question

I recently made a coconut stout that I threw Malibu Rum into when I kegged it. It actually turned out pretty well. I used an entire 750ml bottle which is 25 oz...or approximately a 1/2 oz of rum per 12 oz bottle in a 5 gallon batch.

I'd like to bottle 12 of these to consume at a later date...several months down the road. They will be stored at room temperature and not in the fridge. I'm concerned that after they warm up it might create bottle bombs. Malibu has 6 grams of sugar per ounce x 25 oz = 150 grams of sugar in 5 gallons of beer. But when using priming sugar for bottling I used to use 1 oz per gallon...so 28 grams x 5 = 140 grams total in 5 gallons of beer.

Is it safe to assume that if fermentation does start back up, I won't have problems? Or does carbing with CO2 in a keg, PLUS considering the 150 grams of sugar from the rum mean that I likely will have bottle bombs?

I made a watermelon wheat beer last summer and added 8 cups of watermelon juice to it. I wasn't even really aware of bottle bombs at that time and I didn't have any issues. I was still bottling back then and so I had 120 grams of sugar from the watermelon and 150 grams from the priming sugar which equals 270 grams of total sugar in 5 gallons. It didn't appear like fermentation started back up, I had no bottle bombs, and it wasn't over carbed at all. In fact I thought they could have used a little more carbonation. I added the juice straight to the primary after 2 weeks and the beer finished at 1.012 a week later.

Any advice on this would be greatly appreciated. I want to give some of this beer away as Christmas gifts...some via the mail...but I don't want to give my friends and family glass grenades!

Thanks!

Assuming your math is right, you are worried about 150 g sugar vs 140 g sugar? I wouldn't sweat that.

I had no idea that Malibu rum had sugar in it. You learn something new everyday.

Oh wait, I now just realized you added the rum and carbed it in a keg. Hmmm... not sure what to say on that one.

It's actually High Fructose Corn Syrup, but I would think it would fermentable just like sugar.

So if I understand you, your FG was 1.012 when you kegged. I was in a very similar spot with a strong ale that started at 1.082, and ended - funny enough - at 1.012. I bottled it all up with 4 oz corn sugar (for a 5 gallon batch), and 2 months later I decided to try one and...well, I'm not sure how to break this to ya, but all my bottles were foam-overs (not quite gushers, but certainly not drinkable).

It wasn't until I reread a chapter in Randy Mosher's, Radical Brewing, that I decided to check my stash. Chapter 10 - "Once brewed, Grasshopper, you must learn patience. It takes a long time for the yeast to hack its way through all that sugar under the high-alcohol conditions that quickly develop...It's a good idea to prime barley wines lightly, as there is usually some residual sugar that will eventually ferment."

Anyways, I had to open all my bottles in my sink, and watch in horror as they slowly foamed away. I ended up losing about 1/3 of my beer, and after topping off each of my bottles with each other and re-capping, they had just the right amount of carbonation a month later.

Hope this helps.

It's possible to reduce the carbonation in bottles by gently prying up the cap until the foam starts coming up and then recap it before the foam starts coming out. Wait for the foam to disappear and repeat. I do it on room temp bottles until it's reduced (this can take many times). Then I will refrigerate them so the CO2 goes into solution and then do it a couple more times if necessary.

mrphillips said:

So if I understand you, your FG was 1.012 when you kegged. I was in a very similar spot with a strong ale that started at 1.082, and ended - funny enough - at 1.012. I bottled it all up with 4 oz corn sugar (for a 5 gallon batch), and 2 months later I decided to try one and...well, I'm not sure how to break this to ya, but all my bottles were foam-overs (not quite gushers, but certainly not drinkable).

It wasn't until I reread a chapter in Randy Mosher's, Radical Brewing, that I decided to check my stash. Chapter 10 - "Once brewed, Grasshopper, you must learn patience. It takes a long time for the yeast to hack its way through all that sugar under the high-alcohol conditions that quickly develop...It's a good idea to prime barley wines lightly, as there is usually some residual sugar that will eventually ferment."

Anyways, I had to open all my bottles in my sink, and watch in horror as they slowly foamed away. I ended up losing about 1/3 of my beer, and after topping off each of my bottles with each other and re-capping, they had just the right amount of carbonation a month later.

Hope this helps.

Click to expand...

Thanks for the reply. The final gravity of 1.012 is not the issue. I've done other beers that only finish at 1.024...on purpose like the recipe calls for. And I'm sure the yeast was done working when I kegged this batch. I too, have had gushers, but that was caused by me not cleaning my bottles well enough before sanitizing them. Learned that the hard way after having a few infected batches back to back where every single bottle was a gusher after a certain amount of time in the bottle.

But what I'm talking about here is avoiding bottle bombs...where the bottles actually explode. (I'm planning on bottling straight from the keg and not adding any more priming sugar) But in the keg, in the fridge, whatever yeast is still there is dormant because of the cold temperature...so adding the coconut rum isn't a problem. I'm just trying to find out if the yeast will start eating the sugar from the rum after they are bottled and stored at room temperature.

One thing I just thought of, is that the beer has been in the keg "cold crashing" for 5 weeks now as I've been pulling pints from it. You would think that any yeast left would have dropped out by now. But I'm new to kegging and new to adding things like this to my beer...so I'm just not sure.

mtnagel said:

It's possible to reduce the carbonation in bottles by gently prying up the cap until the foam starts coming up and then recap it before the foam starts coming out. Wait for the foam to disappear and repeat. I do it on room temp bottles until it's reduced (this can take many times). Then I will refrigerate them so the CO2 goes into solution and then do it a couple more times if necessary.

Click to expand...

I guess that is one idea, but that sounds like a pain in the ass. Plus I've heard that when bottling from the keg, that you can lose some carbonation if you aren't careful. I would like this beer to retain the same level of carbonation that it currently has. I'd be afraid that doing that would release too much.

I brewed a high gravity Winter Warmer ale. I tried one at 4 months bottle conditioning and it didn't foam over but tasted harsh. At 6 months it foamed over, I captured all the foam in the glass and after it subsided a bit the beer was better. At a year the bottles were still foaming and the beer was much better. At 1 year 9 months the bottles do not foam over and the beer seems to have past peak taste-wise. And at over 2 years, no foaming and still pretty good.

I wish I had waited on the first half of the bottles.

stewart194 said:

I guess that is one idea, but that sounds like a pain in the ass. Plus I've heard that when bottling from the keg, that you can lose some carbonation if you aren't careful. I would like this beer to retain the same level of carbonation that it currently has. I'd be afraid that doing that would release too much.

Click to expand...

I wasn't saying you will have to do it, just that it's possible to reduce the carbonation post bottling if needed. It is a pain in the ass!

You could always add k-meta and potassium Sorbate to kill off the yeast since you are using a keg to carb.


Sent from somewhere to someone

mtnagel said:

I wasn't saying you will have to do it, just that it's possible to reduce the carbonation post bottling if needed. It is a pain in the ass!

Click to expand...

True. And thanks for the tip. If I get one bottle bomb maybe I would attempt to save the rest this way.

GilSwillBasementBrews said:

You could always add k-meta and potassium Sorbate to kill off the yeast since you are using a keg to carb.

Click to expand...

Thanks! How would I do this exactly? How much do you add? Does it affect the flavor, head retention, or anything like that?

The dosage instructions are on the packet. It is a dry ingredient. I am at work so don't have it here to check but you would just dissolve it in water much like priming sugar and then add it to the beer and let it sit for a few days to kill off the yeast. I let mine sit for a week. (Life distractions) I added mine before kegging and carbing however so I'd watch when you add it to yours as it could cause nucleation points and make your beer foam over. Not sure so be cautious.

Both are dry ingredients. I will check on the proper dosage in the morning for you when I get home. But I want to say it was 1/2 or 1/4tsp per gallon or something close. I will check in the morning for appropriate dosages. Of both.
Sent from somewhere to someone

GilSwillBasementBrews said:

The dosage instructions are on the packet. It is a dry ingredient. I am at work so don't have it here to check but you would just dissolve it in water much like priming sugar and then add it to the beer and let it sit for a few days to kill off the yeast. I let mine sit for a week. (Life distractions) I added mine before kegging and carbing however so I'd watch when you add it to yours as it could cause nucleation points and make your beer foam over. Not sure so be cautious.

Both are dry ingredients. I will check on the proper dosage in the morning for you when I get home. But I want to say it was 1/2 or 1/4tsp per gallon or something close. I will check in the morning for appropriate dosages. Of both.
Sent from somewhere to someone

Click to expand...

Awesome! Thanks!

So add 1/4teaspoon potassium metabisulphite (k-meta) per 6 gallons
( I let that sit 2-3 days).
Then 1/2tsp potassium Sorbate per gallon


Sent from somewhere to someone

Thanks for doing this! What kind of beers have you used this in? Did you do it for the same reason I'm doing it? Did it affect the flavor, head retention, or anything like that in a negative way?

I used it in a root beer that I brewed and wanted to give as couple bottles away an didn't want them to explode on others since I had it carbed in my keg I bottles from there. Since I had added sugar an honey for sweetening when I put it in the keg. And didn't want the yeast waking up in the bottle if others didn't keep them cold.


Sent from somewhere to someone

I didn't notice any off flavors from it.


Sent from somewhere to someone

Thanks again!

I think what I'm going to do with this first batch, is bottle 12 and put them in a box at room temp. Tape it shut and put a trash bag over it for 3 months, just to see what happens. If I get any bottle bombs I will do your method next time for sure. I'll report back to this thread either way.

Not a problem. Let us know how it works out for you.

A plastic tub and lid will be easier clean up than a soggy box with glass shards in it. Just a thought.


Sent from somewhere to someone

Agreed and thanks again for the replies. I've read a ton of brutal bottle bomb stories since I last posted...and they are pretty scary! I had no idea they were that explosive. I went to bottle my remaining keg yesterday, only to find out that I was out of beer! One downside to kegging I suppose...you never know when you're about to run out.

Anyway, after thinking about this more, I think I'm going to try real coconut next time. The malibu rum creates a slightly artificial bitter aftertaste that I'm just not wild about. This beer turned out pretty well, and the base recipe is really solid, but I noticed that if I drank a hoppy IPA first I enjoyed this beer a lot more than if I had it by itself first. I'm starting to think that coconut rum has no place in beer.

If I try this again using a different coconut rum I'll definitely report back. If I decide to bottle it after kegging I'll let you know if I have any bottle bombs. But right now I think I might just skip the rum entirely and use real coconut.