Welcome to 2024, where I've silently noticed the rampant shrinkflation and absurd grocery price hikes slowly squeeze my ever-so-tight food budget every month. I've stopped buying brand name anything, and always look for ways to save money. The second (well, really the first, because this started last year and I'm only now blogging about it) target in my belt-tightening mission: making my soda habit cheaper!
The Problem Child
This was the first brand name to get the hatchet: Coca-Cola brand Diet Coke. A long-time favorite of mine, the distinct flavor and high caffeine content had to be replaced with a (far) cheaper alternative: Grocery Store Brand Diet Cola. As of this writing, the brand name 2-liter costs $4.79 while even the generic soda comes in at $2.49 a 2-liter (up from as low as $.99 on sale initially). With a 4-liter a day habit of soda (I know, I know...) it was costing me more than food some days. I won't even broach the environmental impact of all the plastic packaging coming and going on a weekly basis, with full recycle bins of crushed plastic bottles...
[Note: We're going to use the 2-liter as our standard measurement for this article, even though it'll be confusing as our solution uses 1-liter bottles that are 84% filled. However, I'm trying to beat the grocery store cost of generic brand soda, which for the sake of this article will be $2.50 for a 2-liter of soda.]
(Not) My First Solution
Yes, I adopted SodaStream, with caveats... Much like the razor blade industry, SodaStream figured there's money in customer adoption and the unwillingness to change; Therefore, buying into the SodaStream system means consumable costs including flavor concentrates as well as subscription costs for C02 refills. I avoided using the SodaStream for a long while due to this, as I'd figured out the unwieldy costs for just the carbonation - no flavor! Five CO2 containers costs $84.95 (with free shipping!) from SodaStream, ignoring the included return shipping costs built into the price. SodaStream does not publish the actual tank volume, but suggest you can get 60 (1 liter) bottles of carbonation from each tank, an obvious exaggeration of performance; Considering each 1 liter bottle actually holds .84 liters of water when filled as instructed (need room for expansion), their own '60L' description actually produces 50.4 liters. Others suggest each tank only holds a mere pound of CO2, and you can expect 30 bottles of carbonation per tank in normal use, and a steady $16.99 per lb cost for CO2 from SodaStream. If I maintain my usual soda consumption rate, I'd predicted an annual cost of $1019.40 just for carbonation! The 5-year cost of $5097 shows you just how the profit is earned... Yes, it would be cheaper than store-bought sodas, but not by much, especially after you added in flavor costs too!
| CO2 Weight | Cost Per Pound | Unit Cost | |
| SodaStream Tank | 1 lb | $16.99 | $16.99 |
| Annual SodaStream Cost | 60 lb | $16.99 | $1019.40 |
| 5 Year Cost | 300 lb | $16.99 | $5097.00 |
My D.I.Y. Carbonation Solution
My DIY alternative is to swap out the tiny, vendor-locked carbonation tanks with your own. Easily purchased online, an aluminum 5 lb. CO2 tank and adapter for the vendor-locked tank connector ran me $115.89. The tank is date stamped with its birth, and needs to be replaced or tested and re-certified every 5 years. (Yes, even the SodaStream tanks have a lifecycle and are recycled themselves, hence the mail-in program to centrally unify testing and processing). Our local CO2 supplier, Gas Pro, will handle our testing when the time comes, and offers full refills for the low price of $14.50 each (5 lbs of Beverage-Grade CO2). Our new 5-year cost comes in well under the 1-year cost of sticking with the SodaStream brand name carbonation, even after the upfront costs of hardware!
| CO2 Weight | Cost | Total Cost | |
| 5 Lb. Tank | - | $79.90 | $79.90 |
| SodaStream Adapter | - | $35.99 | $35.99 |
| C02 Refill | 5 lb | $2.90/lb | $14.50 |
| Annual DIY Cost | 60 lb | $4.83/lb | $289.89 |
| 5 Year Cost | 300 lb | $3.28/lb | $985.89 |
I've been keeping tallies of the number of SodaStream 1 liter (read: .84 liter!) bottles I get per full tank, and depending on how carbonated I prefer my water, I get between 140-160 bottles, which is approx. 30 bottles per pound of CO2 (seems on target to earlier estimates!). Today marks the third refill I've gotten on my tank, and now I'm officially well in the black, with a decreasing cost of CO2 from here until May 2028 to achieve the $3.28/lb cost of CO2 and hardware. That averages to around 21ยข per 2-liter of carbonated water.
Not To Sound Tasteless, but...
As for flavor concentrates, I've been a subscriber to The Art of Drink's Patreon channel for the last few months, gleaning tips and hints on making my own flavor concentrations for sodas from host Darcy O'Neil. I have yet to come up with a delicious easy recipe myself, but I do like tinkering and messing about with formulations. When I create my own soda concentrate flavors, I'll see the costs drop even more, as concentrates cost mere pennies per serving. The sugar-free sweeteners are the biggest cost and volume of most soda concentrate recipes; flavor is a minor addition/cost. Alas, my first energy formulation turned out drinkable but not delicious. I'll update this blog as my soda concentrate flavor experiments mature, I'm working on a diet Grapefruit soda to replace my beloved Fresca!
In the meanwhile, I've been purchasing bulk packs of SodaStream flavorings (often generic flavors vs. name brands) of their diet cola and energy flavors when they are on sale, trying to pay under $5 per bottle of flavor concentrate (as low as $3 per bottle on sale occasionally!). As each flavor concentrate bottle is designed to produce nine (1 liter) servings, our 2-liter costs are around $1.21, or less than half our grocery store cost. While it doesn't save me millions of dollars, the savings should really add up over the year, especially with my habit.