Hydrogen water is not carbonated. The two products use completely different gases and produce a noticeably different drinking experience. Carbonated water gets its fizz from dissolved carbon dioxide (CO2), while hydrogen water is infused with molecular hydrogen gas (H2), which does not create the same bubbly, effervescent sensation.
Why Hydrogen Water Doesn’t Fizz
Carbonated water is made by dissolving carbon dioxide into water under high pressure. The CO2 reacts with the water to form carbonic acid, which is what produces the familiar bubbles and that sharp, slightly tangy bite on your tongue. It’s a chemical reaction you can see and feel.
Hydrogen water works differently. Manufacturers infuse pure molecular hydrogen gas into water before sealing it in cans or pouches. Hydrogen is colorless, odorless, and doesn’t react with water the way carbon dioxide does. You won’t see a stream of bubbles rising in the glass, and you won’t feel any fizz when you drink it. Hydrogen water looks, feels, and largely tastes like plain still water.
The Chemistry Behind Each Drink
The distinction comes down to how each gas behaves in water. Carbon dioxide is relatively soluble and chemically reactive. When it dissolves, it forms carbonic acid, lowering the water’s pH and making it mildly acidic, typically in the range of 3 to 5 on the pH scale. That acidity is part of what gives sparkling water its crisp, slightly sour taste.
Molecular hydrogen doesn’t do any of that. It dissolves in water without forming new compounds or changing the water’s chemistry in a way you’d notice. Hydrogen water has a pH that’s the same as or slightly above regular water, which sits at a neutral 7. There’s no acid formation, no tang, no effervescence.
The concentration of hydrogen in these products is also very small. The International Hydrogen Standards Association requires a minimum of 0.5 milligrams of hydrogen per liter for a product to qualify as hydrogen water. That’s a tiny amount of dissolved gas compared to the heavy carbonation in a typical sparkling water.
How Hydrogen Water Is Made
Most hydrogen water is produced by one of two methods. The first involves bubbling pressurized hydrogen gas directly into purified water, then quickly sealing it in aluminum cans or foil pouches to prevent the gas from escaping. Hydrogen molecules are extremely small and escape containers easily, which is why you’ll rarely see hydrogen water sold in standard plastic bottles.
The second method uses electrolysis. Portable hydrogen water generators, which look like high-tech water bottles, pass an electrical current through water to split some of the water molecules apart. This releases molecular hydrogen gas that dissolves back into the remaining water. The result is the same: still water with a small amount of dissolved hydrogen gas, no bubbles or fizz involved.
Sparkling Hydrogen Water Does Exist
Here’s where it gets slightly confusing. A small but growing number of brands now sell sparkling hydrogen water, which combines both gases in a single product. These drinks contain dissolved hydrogen gas for the marketed health angle and carbon dioxide for the fizzy mouthfeel that many people prefer. Products like oHy Hydrogen Sparkling Water use elemental magnesium to generate hydrogen while also carbonating the water for a familiar sparkling texture.
If a hydrogen water product is fizzy, it’s because carbon dioxide has been added separately. The hydrogen itself isn’t responsible for the carbonation. So when you see “sparkling hydrogen water” on a label, you’re looking at a hybrid product, not standard hydrogen water.
Quick Way to Tell Them Apart
- Carbonated water: Infused with CO2. Visibly bubbly, mildly acidic, has a sharp or tangy bite.
- Hydrogen water: Infused with H2. Looks and tastes like still water, neutral pH, no fizz.
- Sparkling hydrogen water: Contains both H2 and CO2. Fizzy like sparkling water, marketed with hydrogen’s proposed benefits.
If you’ve picked up a can of hydrogen water expecting something like a LaCroix, you’ll find flat, neutral-tasting water instead. The product is designed around its dissolved hydrogen content, not its sensory experience. Carbonation and hydrogen infusion solve for completely different things: one is about taste and texture, the other is about delivering molecular hydrogen that proponents believe the body can absorb more readily than the hydrogen already bound to oxygen in a regular water molecule.