The soda siphon is a tool that I recall seeing in old movies and TV shows: usually being sprayed into someone’s face, but I admit I had no idea what that device was. You rarely see soda siphons anymore, maybe because of the availability of canned/bottled soda water, maybe because it’s a tool people don’t understand as well.

I know I didn’t.

I got my hands on what’s probably the most common siphon that I see these days: an iSi (pronounced EEE-see) 1L Soda Siphon, which will run you about $50 at Amazon. My usual source of soda water in my home bar is Hansen’s 8oz Club Soda cans, which cost $3 for a six pack.

Since I’d never used a soda siphon, I watched some YouTube videos on how I could use my new iSi. In the case of this particular model, it’s only designed for water, meaning you shouldn’t be making whipped cream or trying to carbonate cocktails with it. The process goes like this: fill the siphon with water, put the lid on, then screw in a soda charger and shake (chargers run about $1-1.50 apiece). You can either use the soda right away or stick it in the fridge for future use. I found the water in the iSi stays bubbly for about 3 days. When I noticed it losing it’s fizz, I simply re-charged the water, as long as the siphon was still more than half full.

Time for the big question: should everyone have a $50 soda siphon in their home bar? No. A siphon is most useful if you use higher volumes of soda water, probably a liter or more a week. Compared to my Hansen’s cans, iSi soda water is a little bit cheaper: Hansen’s runs you about 6¢ per ounce, and iSi will runs you about 4½¢ per ounce….if you use it all. And that’s the big kicker: if you charge one liter of soda water for $1-1.50 per charge, but don’t use the soda water, then you might be wasting money on re-fizzing your water over and over.

So if you find yourself using soda water a lot in the cocktails you love, or if you make Mojitos, mocktails and Shirley Temples regularly, then the iSi is a good buy. If you have parties regularly with fizz-water drinks, you should get one. Particularly if you keep the charging cartridges on hand, you’ll really never have to go the the store for soda water again (which I’m grateful for).