CO2 adapter?

Get rid of that. Just use a soda bottle and cap as my page describes. So much simpler and more effective, and not hazardous like the ISI modification.

Use a length of unreinforced vinyl tubing in your supply line. It is weaker than a plastic soda bottle and acts as an overpressure safety valve. If your regulator fails open, you'll get a lethal bomb.

Bad idea. Way, way, too much pressure for carbonation. At best you're wasting almost all your gas.

The cartridge-piercing port on the ISI item has a check valve that is impeding your flow and requiring the 250 psi to open. That is necessary for using a 1000 psi cartridge bulb, but quite wrong for carbonation from a gas supply.

No, you can't compare the bulb contents to your 250 psi overloading. The bulb regulates by mass, not pressure like your regulated feed. Your yields are going to be much worse.

Not only easier than you think, but less filling and tastes GREAT! Since following (more or less) Richards most excellent instructions, I've been making at least two liters a day for a few years. I wonder when my 20# tank will run out.

Everything tastes better with bubbles. Give me a place to stand and I can carbonate the world.

First of all the siphon has several advantages over a soda bottle. It is easier to use, it maintains the fizz better without having to top it off after each use, there is an over pressure relief built into the dispenser valve and it looks better on the bar.

There was no modification to the siphon. The only thing I did was drill a hole in the charger cap but it can still be used with regular chargers. Once I dug all the parts out of the junk box it only took about 15 minutes to put together.

For safety's sake I did a little research before I started. Soda siphons have a safe working pressure of 200psi or higher. Commercial carbonators work at 100psi or higher. I also rigged a gauge to the spigot to see what happens. Using a regular 8 gram charger the pressure rises to about 100 psi and slowly drops to about 40psi as the CO2 is absorbed. The charging valve in the siphon acts as a regulator and reduces the supply pressure by about

150psi so using my rig with the regulator set at 250psi the pressure inside the siphon went to 100psi but because the pressure remained constant during charging and I left it on until the bubbles stopped it only dropped to about 50psi at 50F and dropped to 30psi after a night in the refrigerator. It definitely makes a lot more fizz but that is a good thing.

True it may use more gas but at half a cent per charge vs. 60 cents each for the chargers I can accept only getting 10 years out of this cylinder rather than 25. :-)

Your yield calculations are way off. For carbonating at 32 deg F, you want about 30 or 40 psi, yielding 4 volumes of carbonation, not 250 psi. You're way overpressure, which just flashes out when you dispense; there's no point in exceeding 4 or 5 volumes of CO2, because it doesn't make it any more fizzy when dispensed. Your headspace and deadspace vents at 250 psi. I would estimate you're using 30 or more grams of CO2 from your tank per liter of beverage. At about $1/lb for CO2, that's more like 7 cents per liter. Better than the ridiculous bulbs, but you're going to be refilling the tank much more frequently than you think.

You're making 1 liter per bottle, when you could be making 2 or 3 liters with soda bottles. You can fill lots of bottles at once in a session and shelve them like they were store-bought. Much less effort.

No, not really. The problem is having a headspace, and you have that with any partly dispensed bottle, including the siphon.

You *must have* a safety valve like my vinyl hose suggestion. Don't depend on the siphon cap; it is not designed for anything but an 8-gram dose. It can't handle a free-flowing stuck-open regulator at 1000 psi. Boom!

Another problem with the aluminum vessel is you can't burp it, so you need more absolute pressure of CO2 to overcome the air contamination in the headspace.

I've been working on this for 20 years, and like you I started with an ISI "siphon". Other than the retro looks, it's not worth keeping.

I guess we will have to just agree to disagree. :-)

I think we are looking at this from different angles and trying to get different results. My interest is having soda for a couple of Scotches a night. It takes me 2 or 3 days to use up a liter of soda water. What would I do with 2 or 3 liters? It would go flat before I could use half of it. By ease of use I mean I can just pick up the siphon and pull the trigger rather than go to the refrigerator, pull out a bottle, uncap it, pour, recap and replace.

While it is true that the absorption pressure at 32F is about 40psi I am carbonating at 50F to 70F so I don't have to refrigerate it first. That is why commercial carbonators (and regular soda siphons) operate at 100psi. Keep in mind that I am not pressurizing the bottle to 250psi. I just need that much pressure to get 100psi past the fill valve. I will add a length of 265psi tube for a safety blow out though.

It could be as much as 7 cents/charge but when I am paying $30/liter for the "flavoring" at a 2:1 mix ratio 14 cents is rather insignificant. :-)

No, actually the threads hold together pretty well. And, many 20 oz bottles can handle more than the 800 psi that CO2 has at room temperature. I'm sure the 2 litters would probably blow up easier though. :)

Go ahead, ask me how I know. :)

OK, since you asked. I run a small paintball store in the front of my machine shop. I was bored one day so I started messing around with a noise maker. I was hoping I could use a 12 gram CO2 cartridge to blow up a 20 ounce bottle. Unfortunately, it didn't have enough volume to do the job. So, I filled the bottle with water first. Most of the time, there simply wasn't enough pressure. Not one to be beaten, I hooked my apparatus up to a scuba tank. Don't panic, I'm well aware of how dangerous that kind of pressure is. I was using a solenoid valve that I could open from a safe location. A 20 oz bottle makes a very satisfying boom when it gives way. :) And, it usually just splits down the side rather than fragmenting. I was pretty sure I could contain the pieces safely enough. The problem is that paintball tanks have regulators built in that keeps the output pressure to about the same as CO2 at room temperature (around 800 psi). If I had to use a scuba tank, my noise maker got too big and bulky to use discreetly, and it required electricity to operate. It was a fun project, but not one that I could use safely and easily, so it's on the shelf with similar fun projects. :)

Actually, I was disappointed in that too. When I used water in my little experiments, it rarely flew more than about 2 feet.

Well, cheers to your moderation.

What if they made 1 liter soda bottles?

I'm spoiled. I got tired of agitating the bottles, and put in a McCann's carbonator, cold plate, and bar gun. Soda on tap!

Why can't the revenuers do it like the income tax people. I dare say that most home producers would be reasonably happy to give, say, the first 25% away to the government (you know, the bit with all the lead and copper dissolved in it :-)

Mark Rand (only ever run a still to recover paint thinners.. so far) RTFM

having had half a dozen 2 litre PET bottles of ginger beer let go together on a warm day in the kitchen (I assume that the shock from the first caused nucleation in subsequent ones) I can say that a nucleating agent is the thing to have. Put some sharp sand or flour in the water. This will provide lots of nucleating sites for the gas to come out of solution as soon as the pressure is released in the bottle. This will give a much better exhaust velocity.

The bottles had had the lids screwed down so that the yeas would carbonate the beer.... should have drunk it a day earlier :-)

In this case the bottom of the bottles failed, think Trident or Minuteman missile!

Mark Rand

Just be aware of this :

Model airplane fliers in medium and large size - large size can carry several grandchildren inside....

Tried to use PET bottles as air storage for air flaps..... The bottles were lengthwise in the plane. These were at a state and national shows and so many planes exploded and dust and plastic chards with fuel and heavy motors falling ...

Seems the PET isn't rated for very high pressure - and putting it up there, then reducing the outside pressure was like more pressure -

It is just like a gas cylinder that is pressure tested - shards - so take care and Don't overpressure.

Martin

Martin H. Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder IHMSA and NRA Metallic Silhouette maker & member

Mark Rand wrote:

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Hmm ... not *everything*. Did you ever try to carbonate some milk? :-)

Enjoy, DoN.

Sure have! My home is the neighborhood egg cream shop. For those outside the NY area, an egg cream has nothing to do with eggs. It's basically chocolate milk and seltzer. So, of course, in the normal making of an egg cream, we're mixing milk and bubbly water.

In an effort to increase the potecy, we carbonated some milk. It wasn't bad, but it really didn't help the concoction enough to be worthwhile.

The mongolians have been doing it for centuries. Ever heard of Koumis? (Yukkk, by the way... but they like it)

LLoyd