You can make any drink fizzy by dissolving carbon dioxide (CO₂) into it. The simplest way is a countertop carbonation machine like a SodaStream, but you can also use a keg system, natural fermentation with yeast, a chemical reaction with baking soda and citric acid, or even dry ice. Each method has trade-offs in cost, control, and convenience, so the best one depends on what you’re carbonating and how often you plan to do it.
Countertop Carbonation Machines
If you just want sparkling water at home, a countertop carbonator is the fastest path. These devices (SodaStream being the most common) use a small CO₂ canister to inject gas directly into a bottle of cold water. You press a button a few times, the gas dissolves, and you have fizzy water in about 30 seconds.
One important rule: carbonate plain water first, then add any flavoring, juice, or syrup afterward. When CO₂ is dissolved in liquid, it comes out of solution wherever it finds tiny particles or imperfections to cling to. These are called nucleation sites. Plain water has very few of them, but sugars, pulp, and other dissolved ingredients create thousands. If you carbonate a flavored liquid directly, the CO₂ rushes out all at once and you get a foamy eruption instead of a fizzy drink. Carbonate the water, then gently stir in your flavoring.
Forced Carbonation With a Keg
A home keg setup gives you far more control over fizz levels than a countertop machine. The basic system is a Cornelius keg (a 5-gallon stainless steel canister originally used by soda companies), a CO₂ tank, and a pressure regulator. You fill the keg with your beverage, connect the gas, set your desired pressure, and wait.
Carbonation levels are measured in “volumes,” which refers to how many liters of dissolved CO₂ are in each liter of liquid. A good middle-of-the-road target is about 2.2 volumes, which you can hit by setting your regulator to around 8 PSI with the keg refrigerated to 38°F. Different drinks call for different levels. Light, crisp styles like lagers and American ales sit around 2.2 to 2.7 volumes. Heavier styles like stouts and porters are gentler, at 1.7 to 2.3 volumes. Highly carbonated drinks like German wheat beer or fruit lambic can reach 3.0 to 4.5 volumes.
At a set-it-and-forget-it pressure, a keg typically takes about a week to fully carbonate at refrigerator temperatures. You can speed this up dramatically by cranking the pressure to 30 PSI and gently rocking the keg for a few minutes, then dialing back to your serving pressure. This forces more gas into contact with the liquid and can get you drinkable carbonation in a day or two instead of seven.
Carbonation Stones
If you want even faster results, a carbonation stone fits inside the keg and breaks the CO₂ into extremely fine bubbles. It’s a small porous cylinder made of sintered steel or ceramic. When pressurized gas flows through its tiny pores, it emerges as a cloud of microbubbles instead of a few large ones. More surface area means the gas dissolves faster and more evenly. Carbonation stones are popular with small commercial brewers because they cut carbonation time significantly compared to pressurizing a sealed keg and waiting, and they allow precise control over the final fizz level.
Natural Carbonation With Yeast
This is the oldest method: let yeast eat sugar, and the CO₂ it produces gets trapped in a sealed container. It works for beer, cider, kombucha, ginger beer, and homemade sodas. The process is called bottle conditioning.
The basic approach is to add a measured amount of sugar to your finished beverage, seal it in bottles, and store them at room temperature for one to three weeks. The yeast consumes the sugar, producing CO₂ that has nowhere to escape, so it dissolves into the liquid. A standard guideline for a typical carbonation level is about 200 grams of priming sugar (corn sugar or table sugar) for a 5-gallon batch. That works out to roughly 10 grams per liter.
Temperature matters. Warmer rooms (around 70 to 75°F) speed things up, and you may have good carbonation in 7 to 10 days. Cooler rooms (60 to 65°F) slow fermentation, and you might need two to three weeks. The drink will also improve with a few extra days of cold storage in the fridge after carbonation is complete, which helps the CO₂ settle more firmly into solution.
The biggest risk with natural carbonation is too much sugar. If you overshoot, the pressure inside the bottle can exceed what the glass can handle. PET plastic bottles are far safer for this reason. They can withstand roughly 10 volumes of CO₂, compared to about 3 volumes for a standard 12-ounce glass bottle and 7 volumes for a champagne-style bottle. If you’re new to bottle conditioning, use plastic bottles. They’ll bulge and deform before they burst, giving you a visual warning that pressure is building too high. A glass bottle that fails sends dangerous shrapnel in every direction.
Baking Soda and Citric Acid
You can create a quick fizz with a simple chemical reaction. When citric acid meets baking soda (sodium bicarbonate) in water, the two react to produce CO₂ gas. This is the same principle behind bath bombs and fizzy drink tablets.
The ideal ratio is 1 gram of citric acid to 1.3 grams of baking soda. So for a single glass of water (about 250 ml), you might use 2 to 3 grams of citric acid and about 3 to 4 grams of baking soda. The reaction is immediate: drop both into cold water, give it a quick stir, and drink while it’s still bubbling.
This method produces a light, pleasant fizz, but it won’t match the aggressive carbonation of a SodaStream or keg. Much of the CO₂ escapes into the air before it can dissolve. The drink also picks up a slight salty, mineral taste from the sodium bicarbonate. It’s a fun trick and handy in a pinch, but it’s not a great long-term strategy for making sparkling water.
Dry Ice
Dry ice is frozen CO₂, and as it warms up it converts directly from a solid into gas (a process called sublimation). Drop a small piece into a pitcher of water and it will bubble vigorously, dissolving some CO₂ into the liquid as it goes.
A rough starting point is about 1 to 2 ounces of dry ice per liter of liquid, but the exact amount depends on how cold the liquid is and how fizzy you want it. Start with less and add more. Wait until every visible piece has fully sublimated before drinking, because swallowing a chunk of dry ice (which sits at minus 109°F) can cause serious internal burns.
Never seal dry ice inside a closed container. As it sublimates, pressure builds rapidly. A sealed glass bottle can explode violently, and even a sealed plastic bottle becomes a projectile. Use open or loosely covered containers only. Handle dry ice with insulated gloves or tongs, never bare hands. Work in a well-ventilated area, because the CO₂ gas displaces oxygen. In enclosed spaces, high concentrations of CO₂ cause dizziness, rapid breathing, and at extreme levels, unconsciousness.
Cold Liquid Holds More Fizz
Regardless of which method you choose, one principle applies to all of them: cold liquid absorbs and holds CO₂ far better than warm liquid. This is why your soda goes flat faster on a hot day, and why keg carbonation charts always factor in temperature. Chill your water, juice, or base liquid as close to 32°F as possible before carbonating. You’ll get more fizz with less gas, and the bubbles will last longer in the glass.
If you’re carbonating something with sugar or flavoring, remember the nucleation rule. Carbonate plain, cold water first. Then gently fold in your syrup, juice, or flavoring. Pouring aggressively or stirring hard will knock the CO₂ right back out of solution. A slow, gentle mix preserves the bubbles you worked to put in.