For many, sparkling water is the perfect beverage — versatile and utterly refreshing, able to cleanse the palate and it contains zero calories. And it sure seems to be having a moment. Sales of packaged sparkling water have skyrocketed since the pandemic confined so many seltzer fans to their homes, with MarketWatch reporting a dramatic 52 percent jump in March alone. That same month, the demand trickled down to the aluminum can industry and U.S. sales rose 24 percent by volume. If these trends continue, experts predict a widespread can shortage could be on the horizon.

Of course, there are ways of getting your bubbly fix without putting a strain on aluminum reserves or hoarding plastic Polar Seltzer bottles in your pantry. Countertop carbonators like SodaStream are one popular method, but if you drink enough seltzer — as so many of us do — the constant hand pumping, frequent gas cylinder exchanges and limited output (one liter at a time, who can live like that!) are reasons enough to look for bigger, better and more sustainable options. Enter the selzterator, a DIY sparkling-water draft machine guaranteed to revolutionize your home hydration game.

The idea may seem innovative, but it’s actually just a repurposed kegerator, a retrofitted refrigerator device home-brewers and other small-scale beverage makers have been using for decades. The build out is simple once you get into the swing of things, and the majority of the materials can be picked up either new or used from an online marketplace, or from a hardware store or a local home-brew shop. It’s best to research home-brew shops and online forums first, as those folks tend to be full of helpful advice about everything from construction tips and fixes to where to get the best prices on equipment.

The whole exercise takes about a day and can run less than $150 if you buy used and do your research. After that initial investment, you’re looking at a near-endless stream of perfectly calibrated sparkling tap water that costs zero dollars and results in zero waste.

TOOLS

⅞-inch diameter hole saw

Power drill and drill bits

Flathead screwdriver (for tightening metal clamps)

Hex wrench

Spray bottle filled with soapy water

EQUIPMENT

Working mini-fridge with interior shelving removed and no freezer

Five-pound CO2 tank

Clean five-gallon Cornelius/home-brew keg (small enough to fit inside the fridge)

Faucet tower with rubber tower gasket, faucet head, and tap handle (can be purchased separately but buying it as a kit makes things easier)

Liquid line (a standard clear vinyl hose used for kegging systems; runs three- to five-foot with a 3/16-inch diameter and should come included in any faucet tower kit)

CO2 line (the same three- to five-foot 3/16-inch diameter clear vinyl hose as above)

Liquid line connector (ball lock-style quick disconnect)

CO2 line connector (ball lock-style quick disconnect)

Three to five metal screw clamps for both lines

CO2 regulator

METHOD

1. Center your faucet tower on the top of the mini-fridge, then mark the spots where you plan to install the liquid line and tower bolts. Using the hole saw, cut a 1- to 1.5-inch hole through the roof of the fridge for the liquid line, careful not to disrupt any mechanical elements. Then drill corresponding holes for the tower bolts.

2. Unravel the liquid line from the bottom of the tower kit and thread it through the hole into the fridge. Connect the open end of the line to the liquid line connector and secure the connection with a metal clamp.

3. If it’s not already attached, affix the tap handle and faucet head to the tower according to its instructions, then lower the tower down onto the top of the fridge. Insert the tower bolts into their holes and secure each to the interior of the fridge with a washer and nut. Close the fridge, plug it in and leave it to chill at its coldest setting.

4. While the fridge is cooling, connect one end of the CO2 line to the CO2 regulator and secure it with a metal clamp. Attach the CO2 line connector to the other end of the CO2 line and secure it with a metal clamp.

5. Connect the regulator to the CO2 tank and tighten the connection with the hex wrench, making sure the tank and regulator are both in the closed or off position.

6. Fill the keg with clean, cold tap water and lock the lid into place. Using the CO2 line connector, connect the CO2 line to the keg’s “IN” valve — it should snap on smoothly.

7. Twist the CO2 tank to the open position and open the regulator’s valve so CO2 starts flowing through the line and into the keg. Spray the system with soapy water and look for bubbles to indicate gas leaks.

8. Slowly turn the regulator’s knob until the needle on the pressure gauge reaches 40 PSI. At this level, it should take about 24 hours to carbonate the tank. If you want to speed things up, gently roll the keg on the ground for about 10 minutes while maintaining the connection to the CO2 tank. The agitation will help spread the bubbles faster than letting it sit.

9. Carefully place the tank and regulator into the chilled fridge and slide the keg in beside (or in front of) the tank. Connect the liquid line to the keg’s second valve using the liquid line connector. Allow the keg to carbonate for 24 to 36 hours before serving (less if you’ve used the rolling method). When ready to pour, adjust the regulator’s PSI gauge down to 15 to 25 PSI for dispensing (more or less depending on how bubbly you like your seltzer). Grab a glass and enjoy.