Costco Shopper Buys Cans of Kirkland Sparkling Water — Finds One Major Problem With Its Taste

Chuck. Pop. Fizz. This is the characteristic sequence that a soda can goes through when it is burst open. As the pull-tab is twisted, the soda erupts, trails of bubbles die down, and the molecules of CO2 are ushered and dissolved into the person’s bloodstream. The feeling is sublime. And the credit for this goes to the soda manufacturer who trapped these gas molecules into the beverage the same way they add sugar, salt, lemon, or lime, per Live Science. However, like all mortal things, the effervescence of soda can eventually fade. When this happens, people say their soda has gone “flat.”

This flat taste is unsurprising if the soda was left out in the open for a long time. But in a newly opened soda, it’s upsetting. In an August 2024 post, Reddit user u/ScratchyPots shared how over 30 cans of Costco’s Kirkland Signature Sparkling Water turned out to be flat in taste. The product in question wasn’t soda, but sparkling water. But since both are carbonated beverages, the science of fizzling effervescence is just as valid for the sparkling water as it is for soda. Although doctors always recommend still water over sparkling water, many can’t just avoid having a glass or two of seltzer in their daily rituals.

The satisfying snap and the tingly taste hitting the tongue are too good an experience to avoid. “Still water is great for hydration, but you would be surprised at the number of people who don’t like the taste and are unwilling to drink it,” Anne Linge, a registered dietitian-nutritionist at the University of Washington Medical Center, told The New York Times. Despite the sensory experience, this bubbly water can trigger gas, acid reflux, flatulence, and sometimes, cavities in teeth. In case of a flat soda, since the carbon dioxide bubbles have already oozed out of the bottle or the can, it is quite likely that none of these symptoms will be triggered.

What is affected the most is taste. So when the Reddit user encountered that most of their bubbly water tasted flat, they approached the platform to share their confusion. “Anyone else getting flat cans of Kirkland sparkling waters?” they asked the readers, likely referring to the variety pack of 12-oz sparkling water cans. Kirkland Signature offers these cans in assorted colors and assorted flavors such as lime, lemon, and grapefruit. In the bottled version of these seltzers, popular options include black raspberry, kiwi strawberry, and orange mango. The user mentioned that they got flat seltzers in 30 of these packs, while nothing of this sort “happened with the Waterloo or La Croix cases.”

Other users joined the discussion to share similar experiences. “I usually get a flat can or two per case. I've had a couple that were leaking from a random pinhole,” wrote one user. u/Embarrassed_hope8157 shared, “I had several cans leak! Unopened, sealed, just started leaking. Lost fizz. You can tell because the cans get soft.” A few others jumped in to defend the brand. “Strange, I’ve been buying that stuff pretty regularly and never noticed any of them being flat,” said u/discodiscgod. u/im_ashe_man said, “Bought a 30 pack a couple weeks ago. About halfway through them, and they are sparkly as ever.”