Using 2-liter bottles for bottling and dry ice for carbonation.

Howdy, folks. I have a wonderful method of quickly carbonating fresh homebrew that I want to share with you. I use dry ice (CO2 in solid form) to carbonate my fresh homebrew. This method has a couple of advantages over using boiled priming sugar: It's not expensive; it carbonates your brew almost instantly; it comes close to eliminating the unsightly yeast sediment that forms at the bottom of your bottles if you use priming sugar.

First, the dry ice. It is readily available. My local Kroger sells it by the pound for about $1.50 per pound. There are other sources, as well. Welding supply companies commonly sell it. You won't need very much, unless you're bottling a LOT of beer! I usually buy about a pound, which is far more than I need (it only takes 7 to ten grams to carbonate a 2-liter bottle). Dry Ice is EXTREMELY cold (-109.3°F or -78.5°C), so you must be judicious about how you handle it. It will freeze your skin in no time if you're not careful. It typically comes in two forms: Bricks about 7 inches by 4 inches, and pellets. The pellets are much easier to use because they easily fit into the mouth of the bottle. If you buy it in brick form, you'll have to chip off pieces with a hammer or some other implement. Make sure to wear eye protection while chipping off pieces! One little piece in your eye can really mess you up!

You'll need a small digital scale. They're not that expensive: I got mine for about $40 a few years ago to be able to weigh out my brewing grains and hops properly.

I use 2-liter bottles to bottle my homebrew. They work extremely well! One 2-liter is about all I can handle at one sitting, so it works out perfect for me.

Next, the carbonating procedure: Rack your beer from your secondary fermenter into your 2-liter bottles (11 per 6-gallon batch). Make sure to set the bottle that you're going to carbonate on a washcloth before you add the dry ice, as the bottle will start bubbling vigorously as soon as the dry ice is added, and it can get very messy very quickly. I use between 7 and 10 grams of dry ice per 2-liter bottle, depending on how much carbonation I want in that particular bottle. 10 grams will give a LOT of carbonation, while 7 grams is pretty moderate. Weigh and add the dry ice, put the cap on as quickly as possible, and start shaking the bottle vigorously. As soon as you put the cap on the bottle, you'll feel the pressure on it go up very quickly. Shake VIGOROUSLY!!! It takes about 5 minutes of shaking the bottle for the dry ice to completely "dissolve." The dry ice MUST be totally gone before you stop shaking the bottle, otherwise, it can over-pressurize and explode (not a pretty scene, I assure you)! As you shake the bottle, the CO2 will go into solution. This method works best if the beer is as cold as possible.

It is crucially important that you're ready to cap the bottle and begin shaking it as soon as you drop the dry ice in. If the dry ice is allowed to sink to the bottom of the bottle, it can feeeze in place, which can make the plastic brittle enough to fracture. I had this happen to me the other day when bottling. I wasn't paying close attention to what I was doing and set the 2-liter down for a few seconds before I started shaking it. The dry ice sank to the bottom and stuck there. When it EXPLODED in my hand, it sounded like a gunshot and I got a very nasty cut on my hand from the fractured plastic! The bottle that exploded was one of the new-style bottles and was a cheap brand of pop. I don't know if that had anything to do with the bottle bursting, but I recommend using brand-name empty bottles, just to be on the safe side. ALWAYS wear a pair of sturdy leather gloves when attempting this method of carbonating your beer! Eye protection is highly recommended, too.

I DO NOT, repeat NOT recommend trying this with glass bottles, for obvious reasons.

Finally, crack open your freshly-carbonated 2-liter of beer. Enjoy!

Seems like with if you're using 2L bottles already, a carbonator cap would be less dangerous and almost as quick.

Well, I'm not sure I'll try it after the run-down of injuries and explosions, but thanks for sharing! I always find it interesting what people come up with.

And I own a carbonator cap for a 2 liter, they do not carbonate all that quickly. It happens over several days and requires multiple gas additions. They are basically most useful for keeping your beer pressurized for transport from keg to wherever you're going.

Wow, that is SOME process. Do you look like this guy? Kudos for thinking outside the box!

I'm not familiar with a "carbonator cap." Sounds like something you hook a CO2 cartidge up to.

The bottle bursting and the resultant injury was entirely my fault. I've used this method a number of times, with no bad outcomes, until now.

It's a handy method, if you don't want to wait for priming sugar ferment.

Thanks, nutty_gnome! And yeah, I DO kindasorta look like the guy in the pic---except for the bandage on my left hand.

If you're just hooking it onto the gas and not shaking, then yea it'll take a few days. Same principle as the guys fast carbing kegs by shaking/rolling them around.

dbrewski said:

And I own a carbonator cap for a 2 liter, they do not carbonate all that quickly. It happens over several days and requires multiple gas additions. They are basically most useful for keeping your beer pressurized for transport from keg to wherever you're going.

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The carbonator cap takes about 3 minutes to carb up 2L of beer. I take 2L of cold but flat beer, and then put the cap on, I hook the gas up at 30 psi and shake it for about 1.5 minutes. Then I put it down in the fridge and let it settle. Then pour a beer.

I use it mostly for soda, though. It's awesome. From ginger, water, sugar and a squeeze of lemon to carbonated soda in three minutes.

Do yall think this would work in a keg? Sorry if I jack your thread.

Looks like you need all the bells and whistles (keg, CO2 tank, regulator, etc.) to use a carbonator cap. What I've come up with is a way to carbonate your brew without having to have all that expensive stuff.

I'm sure, purplejeepxj, that you COULD toss some dry ice in a keg to get it carbonated. But, you have to be able to REALLY shake the heck out of whatever you drop the dry ice in. And I mean VIGOROUSLY, or else the pressure goes up too high. It'd be a tough row to hoe, unless you're Lou Ferrigno.

One could add in a few grams, seal it up, shake like crazy, and check for proper carbonation. Then add more, until you get the proper foaminess.

is oxidation an issue? i like the idea of trying this with some smaller bottles

A safer way would be to add a tiny bit of dry ice to your red Solo cup of flat beer. It will still carbonate, but without risking a bottle bomb.

Grammie, The Party Pooper

You can use pretty much any size bottle that you want to, progmac. You'll have to do the math to figure out the proper amount of dry ice to use. The smaller the bottle, the more accurate your scale has to be to get it right. I'll see if I can find where I figured out the math and post it for you. It has to do with the gas laws and all that....

Sharona: That wouldn't work at all! In order to properly force carbonate beer, it must be under pressure using this method. Dropping some dry ice in a solo cup would only make a big mess with all of the wild frothing that would surely result. And, if you were unfortunate enough to be inebriated at the time of the quaffing and happened to be in the disfavor of the gods enough to swallow a bit of the dry ice, it wouldn't be pretty!

It is my understanding that cornies can withstand well over 100lbs psi. I cant remember where I read that but correct me if I'm wrong. Could this in fact be a quick method for keg carbing? A liberal application of Henry's law should approximate the answer....any takers?

I bet it would work just fine, Magnanamous. I'd hate for somebody to try it and ruin their kegging setup, though. It'd be hard to properly shake one of those things full of beer, too.

Don't those corny kegs have a pressure release?

I've carbed some stuff in cups with leftover dry ice. The worst tasting is milk. It's just sooo wrong.

The kegs do have a release which are spring operated and double as a safety valve. I might be willing to sacrifice a Corny to the cause.... Any ideas on how much dry CO2 per 5 gal batch to achieve 2.5 vols?

2L is about half a gallon. So 10 2L per corny roughly. He uses 7-10 grams per 2L. So 70-100 grams per corny.

edit: Oh, didn't notice you wanted a specific volume.

Since most finished beer has a FG close to water I would imagine that it has a density less than 1.4g/cm3; it would allow the dry ice to sink. It seems to me that this could at least give one a head start on keg carbonating. Much like when people carb through the liquid dip tube in order to dissolve gas faster. I still suspect that there is something that elludes me about the nature of dry ice...

If shaking really is an issue for the keg you could always put a board on a rolling pin, making a see-saw. Then strap the keg to the board and shake back and forth.

In a keg would shaking really be necessary? I'll pump the gas up to 30 psi when I first keg it and its usually 75% perfect after a day or 2...and since my beer is 125% perfect it all works out!

Just out of curiosity, are you using food grade dry ice?

BBL_Brewer said:

Just out of curiosity, are you using food grade dry ice?

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ROTFL! Yes and this is a food grade post.

Magnanamous said:

The kegs do have a release which are spring operated and double as a safety valve. I might be willing to sacrifice a Corny to the cause.... Any ideas on how much dry CO2 per 5 gal batch to achieve 2.5 vols?

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Using metric units is easier to make the calculations. For 5 gal of beer (18.93L) carbed to 2.5 vol, you'd need:

18.93(L)*2.5(Vol)*44(g/mol)/22.4(L/mol)= 92.96g of CO2 (~3.28oz)

You'll actually need a little less, since the beer will still have some residual CO2 in solution leftover from fermentation. How much is still in solution will depend on the highest temp the beer reached post fermentation.

FWIW I think trying this in a keg is a very bad idea. The pressure will build up much faster than you'll be able to force it into solution (much faster and easier to close a 2L and then vigorously shake it than it is a corny keg). Most corny kegs are rated up to 160psi, and the pressure relief valves are often set to open at 100psi or lower. I'd bet you'll exceed both of those pressures easily. The best case scenario is that the pressure relief valve opens and you spray beer everywhere. Worst case the pressure relief valve doesn't function properly, and someone gets seriously injured when the keg explodes.

Magnanamous said:

In a keg would shaking really be necessary? I'll pump the gas up to 30 psi when I first keg it and its usually 75% perfect after a day or 2...and since my beer is 125% perfect it all works out!

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Yes. Without shaking the pressure will reach even more extreme levels, and be even more dangerous. Think of it this way, at a constant 12 psi it takes nearly 2 weeks for the gas to be absorbed and reach equilibrium, and at a constant 30 psi it takes 2-3 days. What do you think the required pressure is to carb it with only one short blast of CO2? That's the pressure you'll be dealing with if you're not able to force the gas into solution as soon as it starts leaving it's solid form. Even shaking vigorously it's going to be very hard to dissolve the gas into solution anywhere near as fast as it's forming.

Edit: Just for fun, let's try estimating the actual pressure without shaking. I'm guessing the headspace in a full corny keg isn't much larger than 2L, so let's use that as the headspace volume. If we're really optimistic let's guess that 20% of the CO2 gets immediately absorbed into solution before it can bubble into the headspace. Let's also say that you chilled the beer all the way to 36°F, and the dry ice chills it another 2°F, bringing the temp to ~1°C. Using the ideal gas law, dropping 92g of dry ice into the keg and sealing it without any agitation would result in a headspace pressure of ~279 psi. That's really a best case scenario IMO. If you filled the keg up a little further and the headspace was smaller, or if you did this at a warmer temp, or if less than 20% of the gas is instantly absorbed, the pressure would be even higher.

bigrob said:

seems like with if you're using 2l bottles already, a carbonator cap would be less dangerous and almost as quick.

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+1

Sorry to be a buzzkill here, but this sounds a little dangerous to me...hopefully I'm wrong, but I see the vapor pressure of dry ice at room temperature to be 870 psi...perhaps why the OP insists on shaking the 2 liter bottle...I'm out, and not usually risk averse at all

BANG...hiss, a 1/2 keg could be a bomb...

edit...I see JuanMoore already tried to put the fire out.

Magnanamous said:

ROTFL! Yes and this is a food grade post.

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There is such a thing you know?

And I disagree. Your post might have been food grade before you rolled around all over it laughing

HaHA! thanks for all the input guys. The idea is officially shelved. No keg bombs shall be made. It was however, an interesting exercise.

Juan Moore: "FWIW I think trying this in a keg is a very bad idea. The pressure will build up much faster than you'll be able to force it into solution (much faster and easier to close a 2L and then vigorously shake it than it is a corny keg). Most corny kegs are rated up to 160psi, and the pressure relief valves are often set to open at 100psi or lower. I'd bet you'll exceed both of those pressures easily. The best case scenario is that the pressure relief valve opens and you spray beer everywhere. Worst case the pressure relief valve doesn't function properly, and someone gets seriously injured when the keg explodes."

^^^That's exactly the problem. Juan has it right. Dealing with lesser volumes, as I do, makes it far less of a danger than using a keg to try this. It's far easier to vigorously shake a 2-liter bottle than a 5-gallon keg.

I suppose that if one REALLY wanted to give it a shot with a keg, even considering all the possible risks involved, one could do so in stages. Add 10 grams into your Corny, slap the lid on quicly, shake it like you're having a seizure, wait for a few minutes, carefully open the Corny, add another 10 g, repeat. One would have to sample the brew after each dosing of dry ice, though, and one would probably end up out of beer before getting it properly carbonated. I urgently suggest that if one were to attempt this, that one makes absolutely certain that the pressure-release valves are functioning properly! And, go slow. Just tossing in a wad of dry ice is a sure way to mess something up.

Note that when you add dry ice to a liquid, it IMMEDIATELY begins bubbling like mad, and unless one is very quick of wit and wiles, a disatrous mess can quickly result. Beer, with its inherent proclivity to foam in the first place, is especially notorious.

From what I've gleaned over the years, one gram of dry ice at standard temperature and pressure ends up making 0.515 liters of vaporous CO2 when it has sublimed. I suppose one could work out the math from there considering how many volumes of CO2 one wants in their finished brew.

For me, using 2-liter bottles, I worked out the math thusly:

(2 (liters) X 2.5 (volumes)) / 0.515 (volume of CO2 produced by 1 gram of dry ice) =
9.7 grams dry ice total.

This formula neglects standard temp and pressure (I ONLY do this with beer that is at fridge temperature; trying this with room-temp beer is probably not a very good idea), and doesn't take into account how much CO2 is lost before the cap is emplaced after dropping it in. Nor does it take into account the significant expansion of the 2-liter bottle itself.

One final thought. The rate at which CO2 will be taken into solution is directly related to the amount of pressure it is under. The greater the pressure, the greater the rate of absorption.

I think it's absolutely great that my thread has gotten some folks interested in this method! It is, admittedly, not traditional, is a shortcut, and can be highly dangerous if attempted by the careless, but it IS, undoubtedly, a start. And, it works for me using my 2-liter bottles. Thank all of you for taking an interest!

BBL_Brewer: "Just out of curiosity, are you using food grade dry ice?"

I didn't know there was such a thing. I just use the bricks I get a Kroger and a hatchet to chip off little pieces before weighing. I figured that there really isn't much that's going to survive on the stuff in the first place, being so cold and all. I suppose that fungal spores MIGHT survive, and possibly even bacterial spores, but I have never had any contamination problems. {Crosses fingers.}

Yesterday evening, My girlfriend and I sucessfully bottled 6 gallons of beautiful, wonderful, dark beer using 2-liter bottles (11 of them) and dry ice. It went off without a hitch. This method works, and works well. Now I'm ready for Memorial Day! Cheers!

Nec nec nec necro post!

Anyone still doing this? Has anyone done sugar priming for 2 liter bottles? I've never done sheath, I'm curious that the percentage of headpace isn't present in the formulas stated earlier.

http://www.rickety.us/2012/07/extra-fizzy-homemade-carbonated-beverages/

This appears to meld the op's process without having to shake the bottle constantly. It is similar to relying on the release valve for a corny, but with less disastrous potential consequences.

Just add the dry ice, cap with the release valve cap, and replace with a regular cap once carbed.

One would still have to worry, as the op mentioned, about the dry ice making the plastic brittle and fracturing.

Thanks. I came across that when I posted above, while it does seem safer it seems less reliable to get a specific carbonation rate. Soda carbonation is a lot higher than beer carbonation and leaves solution a lot easier, I imagine this would produce a ton of head if attempted with beer.

I'm going to pick some up on my way home tomorrow and give it a shot. I've got about 2 gallons to attempt this with and a few 2L bottles. I'm going to do it in two stages, using half the dry ice in each stage about 2 days apart. This should reduce the change of over cooling the bottles, and reduce the headspace pressure from exploding levels down to somewhat more reasonable levels.

Was really hoping I would be able to find some food grade dry ice pellets, but all the sources in my area are a lot further out of my way so I'm going to get a 1lb block on my way home tomorrow night and crush it up underneath a towel then carefully weighing out some of the chips before using.

Just wanted to let everyone know I survived.

Like I said in the last post, I went with a 2/3 portion at the first go.
Here's what I used for my calculations:
2L volume,
target carb vol of 2.5,
residual c02 from post fermentation ~0.86 vol. I went with an upper end from brewers friend, using 68F even though the beer definitely hit 72.
dry ice needed: g_tot= Liquidvolume*(target_carb_vol - Residual_Carb_vol)*44/22.4 as outlined on post 2/3 (can't remember).
Initial weight added g_1=g*(2/3)
Secondary weight added tomorrow morning: g_2 = g_1/2

This case:
dry ice needed: g_tot= 6.45g.
Initial weight added g_1=4.30 g
Initial pressure achieved: 1.95 vol
Secondary weight added tomorrow morning: g_2 = 2.15 g
secondary pressure achieved, assuming no loss of pressure to environment during transfer (LOL): 2.5 vol

Feedback: I'll probably keep doing this for my pipeline brews to keep the beer flowing, it was super quick, but bottle prime the special brews. Suggestion for next time, look for dry ice pellets if available in your area they're way easier to deal with. If not, take your block, wrap it in a towel, and drop it from about waist level. Take all but a child's fist sized piece, and put it in an insulated bag in the freezer then cover with frozen stuff. Take the fist sized piece, wrap it in the towel and hit it with a hammer. The smaller pieces dissolve/evaporate WAY faster due to higher surface area to volume ratio. Takes about a minute for a marble sized piece to dissolve, the smaller chips were gone almost instantly.

No need to shake profusely, at least for me, I just kept it rolling so the dry ice was never in the same spot for more than a second or two. Pressure on container was actually rather minimal, it was slightly less carbonation than a pop bottle from the store. I was able to squeeze it with one hand and still have a slight amount of give. Not enough to really see, but enough to feel. Maybe a half cm of indentation from the squeeze.

First followup: Did not add secondary addition of dry ice yet. Poured a pint from a 1L bottle (adjusting math respectively). Very thin amount of head, if I were to guess at the carbonation rate I'd probably guess ~1.9-2.1 vol, so math seems at least somewhat accurate. Yay.

Also: beer is tasty. Drinking a zombie dust riff.

Cool as heck man, now I gotta see if I can find some dry ice. I was already planning on bottling up my extras in 2L's (6.5 gal batch) when I keg in the next couple of days. I was researching priming 2L's when I found this. Pretty cool.............. But otherwise I got a carbacap or sugar I guess.

If you have kegging equipment, a carbacap is WAY better, cheaper, and easier. But the dry ice got me by while i was in another state and didn't have all my stuff.

Yeah, I think I was just excited by the idea of the dry ice method. I will probably try sugar priming one (just to try it) and carbacap the rest. Pretty neat you were able to use the dry ice to get it done in a pinch though.