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How to Make Carbonated Water

by Victor @ Taste of Artisan

Glass full of fizzy, bubbly carbonated water on top of a bar fridge.

If you like carbonated water you probably have noticed how expensive it has become over the past 5-7 years. I used to be able to buy a 25 oz  bottle of Perrier for a dollar at the local grocery store, now it’s $1.79. If you like to drink a lot of fizzy liquid it can quickly add up to a nice chunk of change. The good news is that you can make your own carbonated water, and it will only cost you pennies per gallon.

I am a big fan of carbonated water, and so is everyone in my family. I think I had a lot to do with that. We tend to drink a lot more water when it’s carbonated, and drinking plenty of water is good for your body. The problem is that carbonated water isn’t getting any cheaper. It’s quite the opposite, and it can get pretty darn expensive if you drink a lot. That, plus lugging all those bottles from the store, recycling empties, and constantly making sure you don’t run out of the fizzy liquid forced me to look into how to make carbonated water at home. Specifically, I wanted to come up with a solution that would to be:

1. Cost efficient

2. Convenient

3. Easy to use, even for small kids

Jumping a little bit ahead let me tell you that I currently own a DIY kegerator that I use for making sparkling water. I consider it the Rolls Royce of seltzer water makers. It’s got everything I was looking for. It’s an attention grabber too when folks come to visit. Some are disappointed that it dispenses water instead of beer. I am telling them to be patient as the real thing is coming.

I am using carbonated water and seltzer water or simply seltzer interchangeably as they mean the same thing – force carbonated water using CO2 gas. Some people have asked me if one can make club soda at home. The answer is both yes and no.

Seltzer water and club soda are very similar, but there is an important difference between the two. Club soda’s flavor is enhanced by adding mineral-like ingredients such as potassium bicarbonate and potassium sulfate. If you have a way of adding those minerals in your water (for example by using a re-mineralizing water filter that adds those specific minerals), then yes, you can make your own club soda at home. Otherwise it will be plain old seltzer water. While I believe that club soda and seltzer can be easily substituted, some argue that the difference in taste is perceptible.

SodaStream

SodaStream Fountain Jet Home Soda Maker Starter Kit was the obvious first choice to look into and I liked what I saw – a compact package, ease of use and excellent reviews. It promised to be a very decent seltzer water maker and just what I was looking for. I liked what I saw, bought it and used it successfully until I upgraded to the next level water carbonation rig.

Front view of Sodastream machine.
I have to say that SodaStream does its job and it does it well. It’s a compact sparkling water maker that produces adequate carbonation. If you are looking for a compact and a very portable DIY carbonated water maker SodaStream is for you.

When using SodaStream $15 dollar refills, cost per liter varies from $0.25 to $0.4-$0.5 depending on the level of carbonation you want to achieve. With an adapter and a paintball C02 tank the cost will vary from $0.05 to $0.1 per liter depending on the level of carbonation and the number of loud buzzes you will go through during carbonation.

SodaStream pros: 

  • Fairly easy to use for adults
  • Very portable
  • Very compact
  • Reasonably well built
  • Good carbonation
  • Relatively small initial investment of about $80 (for the entry level SodaStream) plus $20-60 for the adapter and $20-25 for the paintball CO2 tank

SodaStream cons: 

  • Not so easy to use for children, but you can help them and its fun to do this together
  • Three loud buzzes as per the instructions are definitely not enough to achieve decent carbonation that is comparable to carbonation in store-bought carbonated water. I would do 5-6
  • Adjusting level of carbonation involves guesswork and experimentation
  • CO2 refills at $15 a pop are somewhat expensive, though in the end there are some savings to be realized. There is a real opportunity to lower the cost of carbonation with the mod described above
  • Water needs to be pre-chilled for quicker and more effective carbonation
  • Need to remember to place carbonated water into fridge to keep it chilled

Modded SodaStream system

Some cost conscious SodaStream users have turned to getting the popular SodaMod SodaStream CO2 adapter which allows utilizing standard paintball tanks with SodaStream. Reportedly, these standard paintball tanks can be refilled at numerous paintball shops and sports goods stores at a fraction of cost – about $3 a pop. The guys at SodaMod will even help you find a refill location if you are not able to locate one yourself, or so they claim.

Sodamod adapter for sodastream system.

Alternatively, Amazon sells a similar CO2 Conversion Adapter for SodaStream Paintball Tank Canister for less than half the price of the SodaMod adapter. You will need to splurge for a paintball CO2 tank too if you go with an adapter.

A word of caution!

Pay close attention to the quality of the CO2 gas you are using to carbonate water. While cheap, paintball shop and sports goods store CO2 gas is most likely not food grade and contains other gases mixed in. Ask before refilling your tanks there. The best advise is to do refills at beverage supply places that cater to food services industry and use food grade CO2 gas.

The Carbonater

The next level up is the The Carbonater system. It requires a slightly larger initial investment of about $140-$150 and to be comfortable using and servicing a gas regulator, gas tubing, etc.  No worries, I am not a plumber and I had no experience with these things before I upgraded to the carbonater rig. It turned out to be very easy to setup and maintain. The most important thing with this setup is to ensure that there are no gas leaks after you put everything together – you don’t want to use your carbonater for a couple of days and then realize you’ve run out of gas. Youtube has excellent videos on how to test your system with soap water. It’s very easy.

Essentially, this setup consists of a CO2 tank

 

Aluminum CO2 tank.

with a regulator to control CO2 gas pressure,

CO2 regulator

which is then connected via a gas line assembly

CO2 hose with connectors

to the Carbonater cap.

blue carbonator cap

Update July 3, 2016

A reader emailed me that Amazon now carries stainless steel carbonation caps, which cost only a dollar more than that the plastic version above. Definitely go for the stainless version, it will last forever with basic care.

stainless carbonator cap
The cap screws on to almost any soda bottle, including 16 oz, 22 oz, 1 quart, and 2 liter bottles. You would fill your bottle with cold water, screw on the cap, turn on the gas and give the bottle a gentle shake to help CO2 gas dissolve in water. You will hear a hissing sound coming from the CO2 tank as the gas is going to the bottle. Once the water is sufficiently carbonated the hissing sound will stop, indicating that carbonation is done. You can leave the cap on the bottle until you are ready to drink the beverage.

Carbonater pros: 

  • Fairly easy to use for adults
  • The build is super solid and will last for years
  • Makes excellently carbonated water, with carbonation levels to suite any taste
  • You can adjust the level of carbonation on the gas regulator once and produce consistent results thereafter
  • CO2 refills are cheaper than even for standard paintball tanks. Costs per liter are the same as when using the kegerator, see below

Carbonater cons: 

  • Les compact and less portable than the SodaStream
  • Initial investment is slightly higher than that of the SodaStream solution
  • Water needs to be pre-chilled for quicker and more effective carbonation
  • Need to remember to place carbonated water into fridge to keep it chilled
  • Not easy to use by younger children

The Kegerator

OK, everyone knows that a kegerator is for dispensing beer, but many have been using kegerators for carbonating water as well. This is the ultimate solution for water carbonation at home. I have been using it for the past 2 years and it’s second to none.

Home carbonated water poured in glass

This solution advances the Carbonater solution by eliminating the Carbonater cap and adding a modified bar fridge (a minimum size of 4.4 cu.ft. Danby bar fridges have long been popular with kegerator DIY’ers), a 5 Gallon Soda/Beer Keg,


Keg to store carbonated water.
and a Single Tap Chrome Draft Beer Kegerator Tower.

Carbonated water tap.
My kegerator setup uses a 15 lb CO2 gas tank. For reference, a 15 lb CO2 tank can carbonate about 50-60 5 gallon kegs of water based on my observations. This is also consistent with this source here.

KEG wth CO2 regulator attached.

Our household goes through about 1 keg of water per week or so, and we would refill the CO2 tank about once a year or so. It’s extremely convenient not having to do this every 3 weeks or even every couple of months. Keep in mind, though, that a 10, 15 or 20-lb CO2 tank will not fit inside a 4.4 cubic feet bar fridge with two 5 gallon kegs in it, and you will need to drill a hole and run the gas line outside.

If you want to keep your CO2 tank inside the fridge you must go with a 5 lb or 2.5 lb CO2 tank. Alternatively, you can go with a single 5 gallon keg and in which a case a 10 lb tank will fit in the fridge. The 15 lb CO2 tank will fit, i tried, but it will be tight and the regulator will need to be in horizontal position and it will be very tight. I think it’s safer to keep a 15 lb tank outside and avoid risking damaging the regulator.

Over time I realized that a one-keg setup has a notable shortcoming – when water runs out you need to fill the keg with water immediately and wait until it carbonates. If you fill it up with room temperature water and let it carbonate at 40 PSI, it will take 24 hours to achieve low but noticeable carbonation, and full 48 hours to get optimum carbonation. Carbonation can be accelerated by using cold water and/or gently rolling the keg on the floor, but that’s not convenient.

You could also potentially carbonate at 60 PSI (stainless steel cornelius soda kegs can withstand up to 130PSI max but I would not recommend going near that high) and then switch back to 25-40 PSI for dispensing, but that involves unnecessary hassle switching pressure back and forth. Because of that I started using 2 kegs in my system. Once water in one keg runs out, I already have a new keg ready for dispensing. The cycle goes as follows:

  1. Connect keg A filled with water to CO2 line and water line. Carbonate for 48 hours
  2. Add keg B filled with water. Move CO2 line from keg A to keg B and carbonate for 48 hours
  3. Move CO2 line back to keg A until it runs out of water (even though keg A is fully carbonated, the pressure will fall eventually the more water you use and you will need to connect CO2 line back for proper dispensing)
  4. Once keg A runs out of water, move water and CO2 lines to keg B for immediate consumption of carbonated water
  5. Refill keg A, add back to the fridge. Move CO2 line from keg B to keg A and carbonate for 48 hours
  6. And so on and so forth…

Two kegs inside a bar fridge with carbonated water.

Update on July 3, 2016

You can easily see that the 2 keg carbonation process that I started off with was not particularly efficient. I later modified my system to be able to carbonate both kegs at the same time. That way I don’t have to remember to switch disconnects back and forth between the kegs. Here is how I did it:

The easiest way, in my opinion, is to add a 2-Way CO2 Manifold. What it does is it allows you to feed CO2 gas from one output on C02 regulator to two kegs. That’s what I did in my system. Going this route I did not have to drill another hole in my fridge and upgrade my CO2 regulator. Here is how it looks:

CO2 hose manifold configuration for a 2-keg kegerator setup.

The CO2 line from the CO2 regulator feeds into the manifold. Then two CO2 lines run into each of the two kegs. Simple as that.

Note that I have a 4-way manifold in my system and have three CO2 lines connected to it. I happened to have a spare 4-way CO2 manifold laying around so I figured I’d use it. I then later added a third line with a 12-foot hose to use when cleaning my beer kegs. You may not need any of that, so a 2-way manifold will suffice.

Keg connectors for a 2-keg kegerator setup

Two-keg kegerator setup that shows connections of kegs and CO2 lines.

I keep the water hose in front of the kegs. That’s not an accident. If you tuck it behind the kegs it will be touching the cooling plate in the back and the water in the hose will often freeze, especially after you add new water and the fridge starts to circulate more often to cool down the water.

Other ways to carbonate two kegs at the same time

Another way is to use a Dual Pressure CO2 Regulator. This will require drilling another hole in the fridge and running a second CO2 line. I think this option is an overkill. Going under the premise that you want the same level of carbonation in both of you kegs, there is absolutely no need to have a dual pressure CO2 regulator.

I happen to use one in another kegerator system of mine (picture below) but I do need different pressures there.

Dual CO2 regulator

A more cost effective way would be to use a CO2 Regulator with WYE’d Dual Check Valves. You still will need to run two CO2 lines to your fridge and drill another hole. However, the cost of buying such a regulator or adding the the WYE’d dual connector to your existing CO2 regulator would still be quite a bit less than buying or upgrading to a dual pressure regulator.

Dual CO2 regulator.

Given that a 15 lb cylinder refill costs me about $25 including taxes, that’s about $0.41 per keg, $0.08 per gallon, or $0.02 per liter. Not bad, ha? It’s freaking awesome! My wife says our kegerator setup was the most useful and the most prudent investment we have ever made. I agree. It’s the best. The cost of water also needs to be considered, but in my case it’s close to free as I use filtered (reverse osmosis, re-mineralized) tap water.

Kegerator pros: 

  • Carbonated water on tap – doesn’t get any more convenient than that
  • Very easy and simple to use for both adult and even younger kids – just pull the handle and pour
  • The build is super solid and will last for years
  • Makes excellently carbonated water, with carbonation levels to suite any taste
  • You can adjust the level of carbonation on the gas regulator once and produce consistent results thereafter
  • CO2 refills are cheaper than even for standard paintball tanks
  • Assuming a 15-20 lb CO2 gas tank, gas refills are needed once a year or even longer
  • Never run out of carbonated water assuming a two-keg system
  • Water is always ice cold, no need to remember to keep the bottle with carbonated water in the fridge or to pre-chill water before carbonation
  • Looks elegant and cool – everyone who comes over to visit wants to know how it works and wants to use it

Kegerator cons: 

  • High initial investment of about $450-$500 (this includes a new 4.4 cu.ft. or larger bar fridge). The cost can be reduced by about $100-$150 by buying used soda/beer keg and bar fridge.
  • Not portable and requires more space
  • Requires drilling one, potentially two holes in the carefully selected bar fridge (though there are numerous detailed guides online on how to turn an bar fridge into a kegerator)
  • Fairly long carbonation time, but this is easily alleviated by a 2-keg setup

Pouring carbonated water in a glass.

So, If you are just venturing into the world of water carbonation at home and are looking for an easy-to-use solution, SodaStream is for you. It makes very good homemade seltzer water with good carbonation. Savings with an un-modded setup are somewhat dubious, but with an adapter and a paintball CO2 tank the savings will be quite significant.

If you are looking to get into or upgrade to a more robust system that allows for consistent and precise control of level of carbonation without spending a lot of money, the Carbonator system is the best choice.  This system is also a good entry level setup if you know you will eventually be upgrading to the Kegerator setup as all of the parts, save for the Carbonator cap, can be reused. Actually, the Carbonator cap can also have its place in the Kegerator system. The cost of carbonated water per liter with this setup is significantly lower than even with the modded SodaStream setup.

If you are looking for the ultimate setup that is also super easy to use even for younger kids, consider getting a Kegerator, like this EdgeStar Full-Size Kegerator.

pre-made kegerator in the kitchen

If you are up to building your own Kegerator, it can be a fun project and will save you a few bucks. A Kegerator looks very elegant and can be easily incorporated into any interior. The cost per liter of carbonated water is the same as that of the Carbonator setup.

Cheers and happy carbonation at home! Drop me a line if you have questions about any of these setups.

Update on October 20, 2016

I’ve been getting many emails and with questions specific to building a kegerator. Given this interest I made a very detailed guide on How to Build a Kegerator. It basically describes everything you need to build a kegerator, down to what bolts and washers you will need. Hope this helps.

Update on March 19, 2019

I got a number of emails from people who procured kegerators or the carbonater systems and were looking for a hassle-free, inexpensive way to get good water. My recommendation is to use an RO water filter with re-mineralization. That’s what I’ve been using over the past 2 years or so and have been very pleased with it.

Here are my recommended under-sink water filtration systems:

This post was updated on March 19, 2019

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