This water bottle cap is like a personal soda drink that you can take with you on the go. It sparkles

When the water entered the bottle, it was flat, and tasted like boring old tap water. When it came out of the water bottle, it sparkled. Not in the almost carbonated, spicy way a fresh can of soda can taste, but a milder fizz, like the same can after you’ve been sipping from it for 10 minutes. And here’s the most interesting part: the transformation happened in the bottle, and not in bulk Countertop soda machine.

The Roam SodaTop is similar to the handheld SodaStream. The lid is where the magic happens. An airtight seal and small CO2 cartridge are key to turning still water into something more exciting. You can attach the top to a water bottle sold by Roam itself, or to a compatible bottle (e.g., HydroFlask).

Roam expects to begin selling SodaTop Directly from their website In the first quarter of 2025 for $50. CO2 cartridges are expected to cost about 70 cents apiece.

Portable carbonation

The process is simple. You insert the CO2 cartridge into the special cap of the SodaTop, release the CO2 into the bottle, squeeze out the excess gas inside and drink. Each cartridge holds one liter of water.

Roam says its stainless steel water bottles are designed to keep drinks cold for 24 hours. If you already have a SodaStream, Roam also has an adapter cap, which will retail for $13, that allows you to carbonate your drinks from the countertop machine.

Flavor is in the air

The only thing you should carbonate in the bottle is water, but that doesn’t mean you can’t add flavor. Flavored syrups or other drink mixes can be added after the carbon dioxide if you want something that tastes good. But Roam is also developing its own ways to add diversity.

CEO Sanjay Guleria said the company is working on flavored CO2 cartridges, which will contain the flavor essence and allow you to make zero-calorie sparkling water using just regular water and the cartridge. Imagine ginger, lemon, yuzu, grapefruit or white peach flavors – natural or freshly flavored sparkling water in your own bottle. This is refreshing.