What is the secret to how the sodastream works to carbonate water at home? (2023 Update)

[gtr]

What is the secret to how the soda stream works to carbonate water at home? Why does it work in only about fifteen seconds (three to five squirts)?

How can I replicate that squirty nozzle using typical air compressor fittings (like an air gun of sorts, but with that long thin nozzle)?

I already built a simple carbonation system using a 5 pound C02 tank, a carbon dioxide regulator, air pressure hose quick connects on beverage pressure hose, and a plastic soda bottle cap drilled in the center with a metal tire valve locked in place (without the inner schrader valve core so it's just a pipe with rubber gaskets that can be tightened on both ends.

That works to carbonate ice cold water in a plastic liter coke bottle but it takes about five minutes at about 50 psi or 60 psi even after squishing the bottle to get all the air (mostly nitrogen) out of the bottle so it's just carbon dioxide in the air space above the top part of the plastic soda bottle where it starts to curve inward and even after swirling & shaking to get more surface area of the water in contact with the carbon dioxide gas.

I'm guessing the secret to the soda stream is that it is unregulated? And that all that unregulated carbon dioxide goes into a teeny tiny nozzle?

If the sodastream is unregulated, then I'm guessing the sodastream squirts the carbon dioxide gas at a bit over 800 psi up to over 1,000 psi (or even

2,000 psi depending only, I think, on the temperature and amount of liquid in the carbon dioxide tank) through that teeny tiny nozzle.

Does it?

Short of taking a sodastream apart and reusing its fittings, and short of hooking the five pound carbon dioxide tank directly to a sodastream machine (which I don't have), what common air hose fitting can I find that squirts the carbon dioxide (unregulated?) into the bottle through a similar teeny tiny nozzle?

Since I'm using car tools (such as the compressor fittings), I'll add them.

[bruce bowser]

Go to where their factory is and ask around.

[Scott Dorsey]

You have it backwards. It's not pressure, it's surface area. It takes several minutes for a conventional soda syphon to come to equilibrium because the CO2 is slowly diffusing into the water at the water's surface. If you make a shallow and flat syphon, the surface area per unit volume will be much smaller, and so it will take less time to reach equilibrium. If you make it tall and narrow, it will take longer.

Shaking it will make it go into solution much faster by increasing the surface area of contact.

What the Sodastream is doing is making a spray of droplets so that the surface area in contact between the CO2 and the water is much higher. This is the same thing that commercial soda fountains have done since the 1940s. No insanely high pressures needed.

No need to make your own. Older Commercial soda systems are pretty much available free for the asking from restaurants upgrading.

I have no idea why this is in rec.autos.tech. If you're making and drinking scotch and sodas, please don't drive.

--scott

[The Real Bev]

Who cares? It costs more to make your own than it does to buy it. Moreover, the CO2 leaks out and you depend on the honesty of the people who fill the CO2 canister. Total waste.

Fortunately I hate carbonation.

[Snag]

Depends on how much CO2 you buy at a time ... I buy mine at the welding supply ... and while I don't have a carbonation device , it wouldn't all that hard to build a rig to recharge the small bottles . If you have a machine shop available ... and I do . Actually I only drink on average one 12 oz soda a day . Mixed with Kentucky bourbon .

[Scott Dorsey]

I think that these are the problems the original poster was trying to solve by constructing a homebuild carbonator.

--scott

[Ed Pawlowski]

Please tell me it is ginger ale and not root beer.

I have heard of people drinking Jack and Coke though.

Woodford Reserve, splash of ginger ale and a Woodford Reserve cherry is nice at times though.

[The Real Bev]

Perhaps if you buy name-brand stuff when it's not on sale...

REI? They were the only people around here who could do it. NOTHING they sell is cheap.

Just buying the flavor-things and the CO2 costs more than real soda, plus the gas for the special trip you have to make to the CO2-supplier.

YMMV, of course.

[Snag]

Ezra Brooks 99 Straight Kentucky Sour Mash Bourbon Whiskey . Comes in a glass bottle stoppered with a cork . Sometimes straight but more often with lemon lime soda . Tonight though it's Vodka Monopolowa potato vodka with OJ .

[rbowman]

Dr. Pepper... snag,s an Ozark boy. Even back in my drinking days I'd sort of lost the taste for bourbon. My father-in-law bought J.W. Dant by the case. It might be better since Heaven Hill bought it. I preferred I. W. Harper, but never turned down Dant.

I don't know about One W Harper but they don't make Black Diamond strings like they used to anymore.

[gtr]

It's actually both, from what I can tell. I've been carbonating water manually for about a decade, where I trade in my new liquid carbon dioxide five pound tank every five years and have it refilled in the interim.

I tested the coca cola bottles which explode at 190 to 200 psi and I saw tests on the net for exploding soda stream bottles at around 320 psi, so the fifty psi that I have the regulator set to is safe and effective.

I have a standard CGA-320 carbon dioxide welding regulator attached to my five pound liquid carbon dioxide tank which I keep upright and which does not have an eductor (siphon) stem so it's gas that goes into the soda bottle.

I generally fill the 1 liter soda bottle about 1/5th of the way with water and then freeze and then I fill it with cold water to the beginning of the curve which leaves about 1/5th air, which I then evacuate by crushing against my side and the counter before turning on the carbon dioxide at around 50 psi to "inflate" the soda bottle.

Then I swirl and shake for about five minutes.

What's _different_ is the soda stream effects the same carbonation in about

5 seconds. All without swirling and shaking.

So the sodastream is effectively *VERY DIFFERENT* in action!

As I said, I've been carbonating water manually for about a decade, where I'm very familiar that it takes exposing surface water to the gases.

But my question revolves around the fact the sodastream does in five seconds what takes me five minutes to do.

That's what I'm asking for help in replicating using some sort of unregulated pointy nozzle tool that I can attach to a regulator hose.

Having manually carbonated water for a decade, I'm extremely familiar with the reverse mentos effect of shaking, where each bubble acts as a nucleation site catalyst for carbon dioxide to go into solution under pressure.

What I don't yet know how to do is to do in five seconds without shaking & swirling what takes me five minutes manually, with shaking & swirling.

What I'm hoping to find is someone who works in a auto or home shop who knows of a fitting that is like the sodastream pin-point unregulated fitting, which I can attach to the end of a hose like an air gun.

Yes. I agree. What I need is a tool I can buy that does the same thing when hooked to the 800 psi of a liquid carbon dioxide unregulated tank output.

That's the question I'm asking of the auto and home groups.

What "air gun" compressor tool or fitting can I buy that puts that nozzle on teh end of a hose attached directly to my liquid carbon dioxide tank?

Actually, I'm pretty sure from my research that the soda stream is NOT regulated. The ONLY on/off valve is inside the 24mm screw-in M18x1.5 brass valve (in addition to two small safety holes and a 10mm safety valve).

That means there *is* "insanely high pressure needed", as far as I can tell. It's this insanely high pressure funneled into a teeny tiny nozzle that carbonates a 1 liter bottle in five seconds instead of five minutes.

What I'm looking for is some kind of automotive or home tool that replicates that teeny tiny nozzle on the end of an insanely high pressure hose (the stainless steel hoses are rated at 4,500 psi for example).

Easier said than done. If it was that easy, nobody would buy a sodastream.

I'm hoping someone in the automotive or home repair areas knows of a "air gun" fitting that I can put, unregulated, on a hose coming _directly_ out of the (nominally 800 psi) liquid carbon dioxide tank.

What I'm looking for is that squirty airgun for insanely high pressures.

[gtr]

Thank you for that idea which is different from what I was thinking about but which might work.

Given I've been carbonating water for a decade using the five minute shake and swirl method at a regulated 50 psi, I'm enamored by the five second sodastream method which shoots a very fine stream of carbon dioxide gas at the unregulated (nominally ~800 psi) pressures in a fine jet stream.

What I'm seeking is that fine unregulated pointy tip "air gun" tool, but your suggestion might also work.

I could put that carbonating stone on the end of a 4,500 psi stainless steel hose at the unregulated tank pressure and see if it carbonates the water faster than the five minutes it's taking now with the shake and swirl method at 50 psi.

[gtr]

I don't know where you get your math from, but it costs around twenty bucks to fill a five pound carbon dioxide tank (it's about the same price for a

20 pound tank, paradoxically).

I got my tank for free from a beer keg that the kids never returned, and I never pay for the five year and ten year inspection since I just refill it until the date expires and then I get a brand new tank in trade in.

Five pounds is roughly around 2,250 grams of carbon dioxide, which would fill over five 410 gram (14.5 ounces) sodastream canisters, at a cost for carbon dioxide of around $4 or $5 per canister.

Each sodastream 14.5 ounce canister is said to fill 60 liters but in reality everyone says it's only around 45 liters in practice so that's around $4 or $5 for 45 liters of carbonated water if my math is right.

I don't know what dry ice costs for every 410 grams but that makes the liquid carbon dioxide about 10 cents per liter if my math above is right.

How is that ten cents per liter for home carbonation more expensive to you? Can you please show your math?

[gtr]

Do you know how much dry ice costs in your area for about 500 grams? It takes 410 grams to fill a sodastream canister but some will sublime. That 410 grams is said to fill 60 liters but most people say it's 45L.

I have a five pound carbon dioxide tank from the welding shop which is not the siphon (eductor) type and which can fill a sodastream canister with liquid carbon dioxide if you tip it upside down to do that refill.

Here's a "rig" to do that, which costs under $45 dollars.

There isn't any need to "build a rig" since for about $45 you can get all sorts of refill rigs already made on Amazon. Here's just one set of links.

That's for refill.

The above "rig" is for refill, but there's also just replacing the 14.5 ounce sodastream canister with your five or twenty pound CO2 tank.

What's interesting is every sodastream canister ALREADY comes with _half_ the "rig" you need to attach a 20 pound (or 5 pound) carbon dioxide tank. You just remove the 24mm neck of any sodastream bottle (which has an integral 10mm safety valve and a couple of safety pores) and attach that to a M18.1.5 fitting on the end of your five or twenty pound CO2 tank. That instantly converts the puny 14.5 ounce sodastream canister to a 2,250 ounce or 9,000 ounce carbon dioxide source in your kitchen.

Most people drill a 1/2 inch hole in the back of the sodastream to effect that connection, where you can see some of them in this search result.

What you need is a high pressure stainless steel 4,500 psi hose though.

I drink about a liter or two of bubbly a day, and the rest of the family consumes another liter a day, so for me that's 30 cents per day if I can figure out how to make it in five seconds per liter instead of five minutes.

That's why I'm hoping to find some kind of automotive or home shop type of air gun that squirts unregulated carbon dioxide gas into the water.

[gtr]

You can carbonate almost any liquid but what makes it harder are the fruit juices bubble like crazy (don't even think of doing it with orange juice).

What you have to do is dilute the fruit juice with the bubbly water afterward, which isn't ideal, but it prevents all that frothing happening.

Also, the sodastream literature is rife with warnings about getting sugar into that tiny nozzle which would clog it up if left there to harden.

I've never used the beer keg carbonators though, but what I've been doing for a decade works, but it takes five minutes to carbonate a liter using the swirl and shake method of ice-cold water at a regulated 50 psi.

What I want to find is a tool that I can add directly to the end of a

4,5000 psi stainless steel hose coming out of the unregulated CO2 tank. Notice that I can find plenty of sodastream adapters on the market but what I want is something that I've never seen on the net, which is why I'm asking for help from the automotive and home repair group.

Is there a pointy air gun that I can hook on the end of that stainless steel hose at an unregulated nominally 800 psi that will squirt a concentrated stream of carbon dioxide into water to carbonate it in five seconds instead of in five minutes?

[gtr]

I should be clear that I'm looking for something in the home or auto shop that isn't anything I've ever seen before - but you may have seen it.

That's why I'm asking for a pointy air gun, similar to the one that comes out of a sodastream bottle, that I can use to carbonate water in five seconds (like a sodastream does) when it takes me five minutes manually.

There's no doubt I can buy a sodastream and easily retrofit my carbon dioxide tank onto the back (since every sodastream M1.5x18 screwtop canister, when cannibalized, comes with the perfect sodastream valve!)

I would buy a 60 inch stainless steel 4,500 psi hose and hook it to the CGA320 of the unregulated carbon dioxide tank like this hose does.

But on the other end, instead of a sodastream nozzle, what I want is some kind of pointy air gun that shoots the carbon dioxide gas at insanely high pressure (just like the sodastream unit does).

The goal would be to carbonate a liter of cold water in five seconds at 800 psi instead of five minutes that it's taking me today at 50 psi.

I already tested many soda bottles which explode at more than 190 psi and I know (from the Internet) that a sodastream bottle will explode at 320 psi, so what we have to do is shoot the 800 psi into the water in short bursts.

All I'm asking of the home repair and auto repair group is for an "air gun" that has a pointy tip that can shoot that air into an enclosed plastic bottle at 800 psi.

I've never seen that tool but maybe you have?

[gtr]

At twenty dollars for five pounds of carbon dioxide, my math works out to about 10 cents per liter of carbonated water, assuming NRE is ignored.

Since I already have that carbon dioxide tank, and since replacing it with a new tank is free every five years, the only cost now to me is the gas.

The sodastream canisters are 410 grams of CO2, and they say they fill 60 liters but it's more like 45 liters by almost all accounts on the net.

Using easy math, that works out to about 10 grams of carbon dioxide per liter of carbonated water.

At about twenty dollars for about 2,250 grams of liquid CO2 (five pounds), that works out to 225 liters of carbonated water for about twenty dollars.

Keeping to easy math, that's about 10 cents per liter of carbonated water. Where do you live that you buy a liter of carbonated water for < 10 cents?

Who mentioned REI? Nice stuff. But expensive.

I do very much love walking around REI though. It makes me WANT to camp!

For flavoring, the only thing I add is a tiny amount of "Calm" which is a magnesium citrate that gives the carbonated water a lemony type of flavor.

I don't know what the commercial flavors cost, but I'll bet it's a lot. Here is a $135 bundle, for example, as my first result on a search.

I don't remember what the magnesium citrate "Calm" powder costs, but one large tub lasts a few years so I think that cost is in the noise level.

[Paul in Houston TX]

This is my guess: Think about a CO2 gun. Pulling the trigger does not empty the entire cartridge. The needed CO2 fills a known volume. The volume has check valves in front and behind the volume. When you pull the trigger it opens the forward check valve causing the CO2 to go down the barrel. Since the pressure is now less than the cartridge it causes the cartridge check valve to close until some other action causes it to open (moving the lever on the gun or the handle or button on the SodaSteam. If I were to make a soda device I would use a small pipe that is inserted into the liquid so that the instantaneous release of the calculated volume would be injected into the liquid causing the liquid to swirl and foam. Use of electrical solenoid valves would be tempting. The volume would have to be carefully calculated. It would not be much, just a few CC's. You could probably figure it out from the max absorption of CO2 in water at a certain temp and pressure.

[gtr]

I've been "doing that" by scouring the Internet for how the sodastream works, which I think I've figured out that it uses completely unregulated short bursts of (nominally 870 psi 68C/154F) CO2 gas which achieves in seconds a magical amount of surface area contact inside a one liter bottle.

What I'm seeking is a tool that might be lying around a home or auto shop that is a "gun" that attaches to a stainless steel high pressure hose which is itself attached to the unregulated carbon dioxide tank. While the sodastream uses a pinpoint tip as the gun barrel, someone suggested a ten dollar Amazon supplied "carbonation stone" as the barrel. Looking up carbonation tools, I find they "typically" cost over a hundred bucks, so there must be a lot to them that I don't yet understand. What's the difference between a five hundred dollar carbonation stone and a ten dollar carbonation stone in terms of what matters for what I'm trying? Can one of these carbonation stones fit into a home/auto shop air gun? I've never used a carbonation stone, but it seems to be a slow process. What I really want is a home/auto shop airgun with a very pointy tip! That's why I'm asking here for your help.

[gtr]

Thank you for these ideas as I first have to figure out how the sodastream works, in order to replicate not only the nozzle but the pressure used.

My original guess was that the sodastream is regulated, but almost everything on the net says a sodastream has no regulator - so it appears that the CO2, surprisingly so, is nominally injected at 870 psi (68C/154F).

Given a 1L coke bottle will burst at just over 190 psi (ask me how I know this), and given even the sodastream bottles will burst at about 320 psi, the sodastream seems to incorporate a pressure overflow which is heard and felt as a burp when the requisite head pressure is acheieved in the bottle.

I'm guessing that burp head pressure relief valve on the sodastream is set to the order of somewhere around 25 psi to not much more than that I think.

I don't have any experience with a CO2 gun, but that brings up a new idea that maybe there is a CO2 gun out there that will do what sodastream does?

It's a good idea to maybe approach a solution by injecting a known volume.

I have nothing against the idea of injecting a known volume of CO2 since it makes perfect sense to approach it that way - but - I think the sodastream volume is only dependent on two things, one of which is how long you hold the button down, and the other is the burp overflow pressure (see above).

As far as I can tell from Internet searches, when you press the sodastream button down, all it does is depress the valve inside the canister which lets the carbon dioxide gas at the top of the canister vent into the water.

I think that's a perfectly practical known-volume method of CO2 insertion, but there's nothing I can find that shows the sodastream using that method directly.

Of course, the sodastream manual says to use short bursts, which itself causes a known volume to swirl inside the container, and the sodastream says to stop when the headspace overflow pressure valve bursts with a burp.

I would do the same except that you don't want the foam. The suggested carbonating stones appear to do just that.

But paradoxically, the sodastream seems to inject the carbon dioxide at a millimeter or two ABOVE the water surface! Why? I don't know. But it works.

There is a sodastream model that is fully automatic & requires 120VAC.

I think the way the sodastream handles the volume is by the burp pressure.

Amounts for a gas (even for a dissolved gas perhaps?) aren't really usefully measured in cc's but in weight due to inevitable pressure & temperature changes affecting the volume (pv=nrt stuff from school).

Since a 410 gram sodastream canister is widely reported to fill 45 liters in practice, it's just a gram under 10 grams of carbon dioxide per liter, maybe even as much as 2 grams under 10 grams due to inevitable waste.

The question is where to get that air gun that will have a pointy tip?