If you're like me you love carbonated (seltzer) water, chances are if you're here that rings true for you as well. No matter the medium, it gets expensive to purchase from the grocery store week after week. I looked to the SodaStream OneTouch to provide some affordable bubbly refreshment, what could be cheaper than "doing it yourself", after all? Unfortunately, after I purchased the device and started digging into the numbers I ran across various stipulations along the way that made the Sodastream less and less compelling.
Misleading from the start
If you look at a cylinder of SodaStream CO2 it "clearly" states that it will provide you with 60 L of carbonated water per refill:
Unfortunately, the fine print of this is that it's really "60, 1 liter bottles". This gets a bit dubious as each 1 L bottle needs to be filled to 0.89 QT (842.25 mL) to carbonate. Multiplying it out, we're left with each "60 L refill" really supplying 50.535 L of carbonated water.
Even if you just go by their numbers, things get a misleading. Their website also states a cylinder can make up to 15 gallons of water, but 15 gallons converts to 56.8 L. I'm assuming this is a rounding issue and wanting a whole number, but it still is a relatively significant difference I would have expected not to be overlooked.
Lost Carbon
If that wasn't enough, as the cylinders are used their carbonation power wanes since the pressure in the cylinder is reduced. Towards the end of the cylinders life, it can no longer carbonate your "1 L" bottle. When this occurs, I measured that there is ~20 g CO2 left in the bottle. For reference, each refill contains 410 g CO2 per its packaging, so with the lost CO2 we're down to 390 g CO2 per refill.
One Touch
During my initial purchase I made the decision to start with the SodaStream OneTouch, the allure of this being I thought it would give consistent results and I wouldn't have to fuss with manual options. Once I got my hands on it, I realized I was somewhat mistaken.
The OneTouch seems to simply work by toggling the valve on the top of the CO2 cylinder with a total "on" time depending on if you select low, medium, or high carbonation.
Unfortunately, as pressure in the cylinder reduces so too does the effectiveness of a given amount of timing having the Co2 cylinder 'open' to your SodaStream bottle. As the Co2 cylinder empties over its life, you'll need to adjust which level of carbonation you select to compensate. For example on a brand new CO2 cylinder I found that the "low" carbonation setting was more than enough to acheieve my desired carbonation, however towards the end of its life I started having to switch to "medium" or "high" carbonation to get the carbonation I was craving.
Therefore, I don't think there is a ton of value in the OneTouch versus manual models, albeit I've never used another variant. The OneTouch doesn't offer consistent performance, and I can't imagine the manual versions are particularly difficult to use to make the electronic model worth it.
Cold Water
CO2 is easier to dissolve in cold water than it is warm water. This most likely works out well, however it's worth noting this means you need to have some access to chilled water for the Sodastream to work best. If you already have filtered water in a pitcher, that will work fine. If you don't normally keep water in your refrigerator, then that's something you'll need to plan for.
Bottle Sizes
For the OneTouch, Sodastream offers 0.5 L bottles and 1 L bottles. At first I thought this was great, it would be nice to choose how much water you want to carbonate and you may not always want a 1 L bottle full of carbonated water. Unfortunately the Onetouch doesn't have any way to detect which bottle you're using, and just pulses the CO2 for a set amount depending on the setting then vents out the CO2 that does not get "caught" in the water. I did a quick test, and the 1 L bottle took 7.4 grams to carbonate on the medium setting and the 0.5 L bottle took 8.5 g. Unfortunately this makes the smaller bottles essentially useless, as they take the same or more CO2 to carbonate for half the amount of water.
Changing Standards
A few months after my purchase, SodaStream has started selling and exchanging a new "quick connect" CO2 cylinder as well as the 'old' screw in CO2 cylinder:
"Innovation" will of course happen with a kitchen gadget like this, but I'm disappointed in the way that they are approaching the refills. The old style isn't compatible with the new style SodaStreams and vice versa.
They're also still selling machines that utilize both the new and old CO2 cylinders, so hopefully they will keep supporting both, but without any cross compatibility it would be hard to recommend buying an older machine if you for some reason wanted to.
CO2 Exchanges
SodaStream offers either in-store refills at various retailers (Kohl's, Staples, Walmart, etc...) or through the mail directly through them. At current prices, exchanges are $14.99 each. Through the online option, shipping breaks down as:
I tried visiting both a Target and Kohl's near me to exchange my (old style) cylinders, and both only had the new style cylinders and were unable to do anything with my "screw in" refills. Right now this leaves my only option as doing the mail in exchange, which is both less convenient as I'll have to drop off my empty cylinders and potentially significantly more costly if there aren't 4 empty cylinders to exchange
Price per Liter (L)
Personally this is where the Sodastream falls apart for me. From the extra effort listed above such as exchanging cylinders and storing cold water to the upfront cost of buying the actual Soda stream and cylinders you'd expect the savings to be enough to make your money back over time if you consume a lot of carbonated water. Unfortunately, the cost is fairly close to what you can buy at the store for name brands and more expensive than store brands; in this case the store brand I'm comparing comes from Stop & Shop. For a frame of reference, here's the price per L for a few different options:
For the price of Sodastream usage I've created the following table comparison of pure carbonated water and flavoring from both Bubly and Flavor Essence. Personally I found I preferred the Flavor Essence drops over the Bubly, and still like using them in plain water or mixed drinks. I chose to compare the Bubly cost also, as that is the "official" flavoring that Sodastream references. Sodastream instructions state to use ¾ teaspoon (3.70 mL) of Bubly per "1 L bottle", and recall from before each 1 L bottle actually makes 842.25 mL of seltzer water. I also found that I thought the flavor best using the same amount of Flavor Essence per bottle. Breaking this down, I've created the following table with the price per L:
Noting the in-store prices for Seltzer, Sodastream produces seltzer priced between Polar and store brand. However, with the initial investment required, it's definitely a hard sell.
If we go a step further and assume a best possible case scenario that no CO2 is wasted and each cylinder makes 60 L of carbonated water, the price per L of carbonated water comes down to $0.25/L, but the flavorings still put the pricing of this firmly between the store prices:
I've included the spreadsheet (ODS) file here if you'd like to play around with the numbers yourself:
Positive Notes
The Sodastream system does have some positives, if you want to experiment with flavoring your seltzer water in different variations than you may find at the store the world is your oyster. There are also flavorings available that you can't find in stores, such as one of my favorites from Flavor Essence, honeycrisp apple. If you don't want to flavor your seltzer at all, the Sodastream can also provide carbonated water at a fraction of the in store price even with all the considerations we discussed above.
If you live in a location that makes it inconvenient to bring in groceries, such as the top floor of an apartment, it's also somewhat convenient not having to bring up cases of carbonated water.
There is also the environmental aspect, you are preventing the equivalent in cans or plastic bottles being sent off into the world after you are done with them using the Sodastream so that probably counts for something.
Final Thoughts
I was initially excited about the Sodastream, I love seltzer water and anticipated significant savings by performing the carbonation at home. Unfortunately as we learned the savings isn't substantial, and in some cases it's not there at all. It's not a bad kitchen gadget and so far has worked as advertised, but with the large initial upfront investment to ultimately not be particularly savings focused make it a hard sell.
An even harder pill to swallow is their changing standard of the CO2 cylinder, preventing me from exchanging for refills in stores around me. I can only imagine they ultimately will stop selling the old screw in style blue cylinders and force you to switch to the quick connects or be left in the dust, but we'll see what the future holds.
So who could this be for? If you particularly enjoy plain, unflavored, carbonated water this could eventually save you some money as we found the cost before is $0.34/L, but still keep in mind the upfront cost.
I've decided on 2 stars for the Sodastream, the device itself works fine though is a bit bare bones in terms of functionality. My main qualm with it is the lack of savings compared to store bought seltzer water, and if you aren't saving money after the upfront cost of the Sodastream then I have a tough time seeing a huge benefit to it.
SodaStream
For the extra upfront cost and effort of having a Sodastream I would have expected savings that quickly added up, unfortunately when all is said and done the cost of Sodastream flavored carbonated water quickly comes out to the same or more per liter than just going to the store and buying it pre-made.
