Force Carbonating Root Beer With Dry Ice

[Paul] is sick and tired of his homemade root beer being flat. He analyzed the problem with his carbonation techniques and ended up with a method of force carbonating beverages using dry ice.

He starts of by discussing the various methods that are used to carbonate beverages. There’s the old yeast and sugar trick that takes place inside of a sealed bottle. But this takes time, and if you don’t calculate the mixture correctly you could have over or under carbonated bottles (or exploding bottles in the case of glass beer bottling). [Paul] himself has tried the dry ice in a cooler full of root beer method. The problem is that the cooler isn’t pressurized so the carbonation level is very low. You need to have cold temperatures, high pressure, and the presence of carbon dioxide all at the same time in order to achieve high levels of carbonation.

His solution is to use a 60 PSI safety valve. He drilled a hole in a plastic bottle cap to receive the valve. He then drops a few chunks of dry ice in and seals it up. The valve will automatically release the gas as the pressure builds past the 60 PSI mark. What he ends up with is a highly carbonated beverage in a matter of minutes.

If you don’t mind spending some cash you can use an adjustable pressure regulator. This way you can carbonate just about anything.

[Thanks Steven]

49 thoughts on “Force Carbonating Root Beer With Dry Ice

    1. You mean I’m going to have to call the plumber back and have him change out all the shut-off valves and shower elbows in my house for something else? I don’t think so. Most brass either has no lead, or has a negligible amount.

      1. How can you be sure? The enormity of the task (changing valves and fittings) doesn’t change their lead content.

        And in California and in Vermont, brass plumbing fixtures and pipes used to convey water for human consumption must have not more than 0.25% lead by weight by January 1, 2010.

        Trumpets don’t have legal lead limits, despite being made of brass and intended to be mouthed.

      2. @Hack Man: It changes the lead content if you use stainless instead of brass. But, that gets expensive very quickly. And, you’re missing the point. Just having a little lead in it doesn’t make it dangerous. That’s why the requirement is .25% instead of 0%. It’s called “lead-free” because there’s a negligible amount in there.

      3. 0.25% isn’t really negligible.

        Better than pipes made out of lead. Literally. Pipes that were made out of lead. 100% lead. There are quite a few homes that still have these today.

        Romans used to put lead in their drink intentionally as it tastes quite good or so I hear. Still doesn’t make it a good idea though.

      4. In modern plumbing (as opposed to ancient Roman, where you may notice that “Plumb” is the Latin root for “lead”), there may be lead in the solder, but lead pipes are only used for drainage, just as some kinds of plastic are only used for drainage. My old 1930s house used a lead pipe to connect the bathtub drain to the drainage pipes, because it’s very flexible (useful when installing the tub into arbitrary-shaped spaces) and can be soldered watertight. The catch, of course, is that it’s soft enough that you can’t run a Roto-Rooter through it if it clogs up, because otherwise you’ll have a much larger plumbing problem.

      1. Stainless is an option; However, at $90 for a stainless valve compared to a nickel-plated valve at $15 it stops being cost effective; you may as well buy one of those personal soda machines.

      2. Would you prefer that medical equipment manufacturers or soda bottlers or food processors or pharmaceutical companies use brass then, because “some lead is fine” and it’s cheaper too!

      3. ‘Duino your treading near troll territory but I’ll give you the benefit of the doubt.
        I was not recommending a bare brass valve but a nickel-plated valve which is fine for casual contact with food and I was not arguing against stainless it is the ideal option however for a homemade project it would more expensive to make it yourself using stainless parts than it would be to purchase a finished system.

    2. Even if the VALVE does contain lead, so long as it doesn’t come into contact with the soda/root beer/beverage in the bottle, no harm no foul, just change the cap before storage. And you can order food-safe stainless steel valves and tubing to move the pressure release mechanism away from the contents of the bottle. the comment to use a regulator would negate that outright and would also allow for different containers and different levels of carbonation. Regardless, this is going in my folder of “things to remember after the end of the civilized world” :P

    3. lead in brass is generally safe, water needs to maintain contact for long periods for the lead to leech out of the brass in any significant amount.

      I deal with faucets and potable water. ‘In extreme cases, older faucets can contribute up to one-third of the lead in water that has been sitting in the pipes for several hours, with the remainder coming from other plumbing such as pre-1988 lead solder joints in copper pipes. Residents who let the water run at the tap in the morning for one minute and use cold water for cooking should have little concern with respect to lead in the drinking water.’

    1. It’s still difficult for places with no readily available dry ice.

      The alternative is to use a secondary bottle with baking soda and water, or plain soda and vinegar. Connect the two with a hose, and you got a chemical carbonation machine.

      1. No need for the scare quotes around “brew” – you’re actually brewing it. Also, you don’t need sunlight (and typically don’t want it) – you just need moderately warm temperatures.

        I’ve made root beer using one of those kits. The bottle caps have a hole in the top and a flexible piece of plastic foam underneath, which gives you some approximation to a vapor lock and pressure release valve. If pressures get too high the CO2 will leak out, but otherwise it stays around long enough to dissolve in the root beer.

  1. There is a home brew beer kit that comes in 2 liter bottles with a pressure release cap that works the same way for a lot less money than a brass pressure release valve. It’s basically a normal bottle cap with a pinhole in a rubber insert.

  2. Wait, what? Back in high school, our teacher did a demonstration about pH using a large graduated cylinder, a solution of water with a bit of some universal pH indicator, and dry ice. When she added the dry ice to the water, the dry ice and water created carbonate ions, which made carbonic acid (H2CO3). This resulted in the water turning from green to red.

    Long story short, I thought putting dry ice in water created carbonic acid making the solution more acidic. If I understand this article correctly, he’s plopping some dry ice into his root beer? I wouldn’t think that would be safe to drink after that process. Although, it’s been a while since high school and my chemestry is pretty rusty. Any chemestry experts out there know anything more on the subject?

    1. Wait, hurp durp. After more googling, it looks like carbonated water is always inharently acidic, and this would be completely normal for any method of carbonating water. Nevermind

      1. This acid doesn’t really exist – it’s a fancy name for CO2 dissolved in water. Some of it breaks down to ions and forms this (extremely weak) acid, but if you let your water go flat, it will recombine and leave you with plain water.

  3. My fillings contain mercury which is supposed to be in food, but it’s in my mouth. I would use a brass valve and make sure not to slop the root beer up by the valve. Maybe I could get so safety conscious, that I talk myself out even making root beer. Yeah that’s it.

    1. DOH! I meant to say mercury which is NOT suppposed to be in food. Yeah, being a bit cynical in defense of this fella. If it’s for your own private root beer stash, you should be good to go. When you start selling it, then everyone’s hands are in your pockets and you got abide by a plethora of codes including not using brass around food. There’s more harmful stuff in my fillings than there is in those brass valves.

      1. I think we can all agree though that SOME regulation on mercury is probably a good thing. The question, of course, are how much regulation? Who sets those levels? What about other things other than Mercury…. it’s not easy.

        Customers, all else equal, probably prefer to buy the mercury free product as long as they know that mercury is a problem. This assumes that consumers actually know that mercury is harmful AND also the product in question actually discloses what is in it AND is being truthful when they do so.

  4. Okay, so CO2 + water = carbonic acid.

    When building soda fountains, I was always told to avoid anything with copper (like brass) getting into contact with carbonic acid. I was told it was nasty stuff…

    Although now that I do some simple google searches I don’t see anything immediately jumping out at me?

  5. Got a lot of scars in my legs and a glass shard buried somewhere in my Musculus vastus lateralis, from the last time I’ve tried “force carbonating” something with dry ice.
    I wish we had plastic bottles back then :/

    Be careful!

  6. Ok, lead OCD anxietists, I’ve been in contact with lead in some form since I was a teen. I’m now over 40 years old, and there has not been one single symptom of lead poisoning present during my entire life. I’ve handled lead solder for literally more than 20 years. I’ve cast lead into various paperweights for the fun of it. I don’t fear handling lead nor do I fear the minuscule amounts present in modern brass fittings. The whole thing is way overblown with most of the proponents of being cautious about lead constantly screaming, “think of the children!”. :-)

    At some point, you have to bring some common sense to the table. What are the symptoms of lead poisoning? Have you ever seen anyone with said symptoms? Just how much lead does it really take for it to be toxic? Think and do some research before you judge.

    Beyond that, this project has some problems. You should not rely on just one pressure relief valve for your safety. Dry ice can easily create pressures up to 800psi at room temperature and it only takes one valve that doesn’t work correctly to cause a real safety issue. I’d advocate using multiple pressure reliefs to ensure a single failure does not result in a bottle bomb.

    Furthermore, a simple chemical reaction can be used to get your supply of CO2 without resorting to using dry ice. Common baking soda and white vinegar react together to form CO2. Everyone pretty much has this stuff sitting in their kitchen, so why go through the bother of procuring dry ice when you can do it for pennies using household chemicals? Seems odd to me…

    1. Dry ice is readily available in grocery stores here for around $1 a pound. It takes probabably 25 cents worth to carbonate 3 liters, plus it helps chill the drink too.

      1. i did read the title. you can carbonate rootbeer using the method I proposed by simply manifolding two bottles together. one holds the beverage, the other holds the chemical reaction. it’s not that big of a leap to figure that out, if that’s what you’re referring to.

    2. There is no way to know if you suffered brain damage from exposure to lead unless you get tested, even then you may not be able to tell if you would have been smarter without lead exposure. Exposure to lead tends to make people quick to anger, lower IQ,s, learning disorders. It also makes leaves them with the desire to correct people online while being overly concerned about safety issues.

  7. Alternatively,
    Fit a pressure gauge instead of the valve
    add increasing weighed or measured quantities of Dry ice until a suitable pressure is achieved.
    Repeat in future with a plain cap.

  8. I have seen this done a slightly different way. An old scuba tank was partially filled with dry ice and the hose placed on a tap attached to the lid of the bottle. When used with valves the pressure could be controlled eliminating the need for a safety valve.

  9. As an amateur fermenter of beverages, yeast would do just as well. You can only carbonate something so much before it’s vessel explodes. Put yeast in with the cap closed, let it sit for a day or two until the bottle is completely solid, put it in a refrigerator, siphon it out of the bottle to separate the yeast and the root beer, put it back in the refrigerator or drink it.

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