Soda Water from your Kegerator!


By Shung Chieh

We bought a Sodastream appliance many years ago, not long after they came out. The thought of saving money on soda water was quite appealing, and it was a cool gadget that appealed to the DIY’er and homebrewer in me. We used it for a while, and even got a second gas canister. Unfortunately though, the gas canisters don’t last very long, and were still somewhat costly to get filled. Since I was already home brewing at the time and had already transitioned to a CO2 setup for kegging, I thought I’d try to reduce the cost and inconvenience by refilling the sodastream gas canisters myself from my CO2 cylinder. So I bought a sodastream canister refill regulator setup, and tried re-filling the canisters a couple times. Unfortunately, it was somewhat tricky to refill the canisters since you had to re-fill them carefully to prevent tripping an over-filling valve in them, and also had to turn the CO2 tank upside down during the process because mine lacks a siphon tube. Without a siphon tube, if you leave the CO2 tank upright, you end up filling the sodastream canisters with a small amount of gaseous CO2, instead of liquid CO2. Turning the CO2 tank upside down allows you to fill the sodastream canister with liquid CO2, but as you can imagine, this makes the procedure more complicated. I ended up re-filling the canisters a couple times, but each time, it seemed the canisters didn’t last that long, and it was quite inconvenient to refill them on a frequent basis. So… after a while, the sodastream ended up unused, gathering dust on the countertop, and (sigh) we were back to buying soda water because that was much more convenient.
Since I knew I had most of the equipment for making soda water with my kegging setup, this situation annoyed me to no end. I thought there must be an easy way to generate soda water conveniently, and cost-effectively. I did a bit of research and came across Kegland’s carbonator keg lid. Well, it still involved a bit of work to set up, since you need a water line, and potentially a regulator for the water to feed to the keg and carbonator lid. So, that required enough activation energy that it ended up in the To-Do pile for at least another year or two. Meanwhile, we kept buying soda water. I briefly looked at refrigeration units that made soda water and scanned craigslist for old soda machine setups, but wanted to avoid digging an even bigger black hole that the sodastream had already started.
When I set up my home-made kegerator 15 years ago, I put as few holes in the fridge door as I could get away with. This meant that I needed to keep the CO2 tank inside the fridge, which took up precious space, and also made it difficult to manage gas/beer lines etc. It took about 10 years, but finally the annoyance finally got the best of me, and I decided to optimize my DIY kegerator setup. This also seemed like a good time to consider the carbonator lid solution. My plan was to drill a hole for the CO2 line, and while I was at it, I might as well drill a hole for a water line, and set up a carbonator lid to try out. Well it turned out to be pretty straightforward and in hindsight, I wish I had done this earlier. I replaced my gas and liquid line setup at the same time for a duotight setup (highly recommended!), and also added two secondary duotight regulators so I could individually control the CO2 pressure for each beverage line.
Kegland recommends you use water pressure to 10-15 psi above the gas pressure feeding to the carbonator lid. My house water pressure was in the 80-90 psi range, so I definitely needed a regulator and ended up using an older ¼” line regulator I had from before to regulate the water pressure and included a gauge and fittings so I could see and set the water pressure appropriately. The CO2 pressure that seems to be good, and gives the soda water a nice “bite” ended up being 30-35 psi, so that meant setting the water pressure to 45-50 psi.

My Soda Water setup:

● Water coming from an old washing machine setup that’s in the garage and conveniently located near the hacked fridge kegerator. I added an inexpensive water filter that’s used for filtering water for a fridge water dispensing system. Then from the filter to the water regulator, and then into the ball-lock post on top of the carbonator lid.
● At the CO2 tank regulate, I set the pressure to 30 psi and then split between a gas line that goes directly to the carbonator lid (via a ball-lock connect), and two lines, each with their own duotight regulator for regulating down gas to 8-15 psi to feed up to two beer kegs. In front of the beer lines, I have a duotight valve so I can shut each line off depending on need.
● The beverage line from the kegerator lid tank then feeds to its own tap. Since I was a bit concerned about leakage, I ended up using a stainless intertap tap with a self-closing spring. I liked this so much, I replaced my older taps with nukataps and added self-closing springs on those too. After I was satisfied that we liked the carbonator setup, as extra insurance, I installed a water leak detector-controlled valve for the water line. If the water leak detector detects a leak, it trips the valve for the water line.
How does the setup work? Water is fed to the center ball lock post in the lid, while the beverage-out post and gas in post are used as per a regular keg setup. The carbonator lid is quite ingenious, it includes a float valve that re-fills the keg once the water level drops (from use), so it continuously keeps the keg filled with water. Do consult the videos and instructions for how to put the kegerator lid into a keg since it only goes in one specific way. It’s not difficult once you figure it out, but it’s not obvious either. As mentioned, pressure for the CO2 line is set at 20-35 psi, depending on the amount of carbonation that’s desired. Since the carbonation of the water is best at low temperatures, the keg needed to sit at temperature with water and CO2 before the setup consistently produced soda water. It’s continuously refilled with water and CO2. It works beautifully, is quite convenient, and cost-effective since I’m using a 10# CO2 tank. It was working so well, that I decided to buy a 20# CO2 tank to reduce the usage cost that much more.
Make sure to do a leak test without filling the keg with water. I turned off the water line, and checked that the keg and water gas/beer gas lines, valves and regulators held pressure, before putting the system into active use. The keg used for water is a half-keg, and it’s been in constant use. Since it’s soda water, and somewhat acidic with the dissolved CO2 in the water, there’s no danger of bacteria or other infection. So aside from making sure the main CO2 tank has gas, there’s really no maintenance anticipated.
The whole family has been enjoying having soda water on-demand, and it’s been great for parties as well. In fact, our consumption of water in general has gone up, and I also find that it’s such a good thirst quencher, that I reach for this before I reach for a beer. It’s got the approval of the Mrs and the kids, and has helped to justify the expense of my kegging system, which was not insignificant either. Plus the optimized gas/beer setup has been much more convenient and enjoyable to use now!

Recommended parts for building your own:

4. Gas line, regulated to 30psi
6. OPTIONAL: water leak detector that controls a water valve

Figure 1. View of the kegerator lid from below the lid. This is the float valve that is used to maintain a set amount of water in the keg.
Figure 2. View of the keg lid on a 2.5lb keg that I use to store and carbonate the soda water. The center post receives the blue line ( incoming water), while the gas (CO2) and beverage (soda water) posts are used as per usual.

Figure 3. Setup outside the keg. The water line (blue) is filtered (refrigerator water filter), then regulated (duotight regulator prior to the T and gauge). I also have an optional water leak detector and solenoid-controlled valve to shut off the water if a leak is detected.
Figure 4. Close-up of solenoid valve (top), regulator (bottom left) and water gauge and set water pressure (50psi).
Figure 5. Taps! Center tap (silver handle) is for soda water, while the black-handled taps are for beer.

Related Products

All contents copyright 2023 by MoreFlavor Inc. All rights reserved. No part of this document or the related files may be reproduced or transmitted in any form, by any means (electronic, photocopying, recording, or otherwise) without the prior written permission of the publisher.