Review: VacOne Coffee Air Brewer

My coffee routine has been set in stone since the Obama administration. After years of trying different methods and gadgets, I arrived at a simple pour-over setup with a Kalita Wave dripper, and I've stuck with that for about a decade. It's easy to master, consistent, and makes a great single cup of coffee. Two months ago, however, I stashed my old pour-over rig at the back of my kitchen cupboard so I could test a machine that makes an even more consistent and delicious cup of coffee.

The device is called the VacOne Coffee Air Brewer, and it's made up of two pieces. The lower half is a borosilicate glass carafe, and the the top half is a bucket-like plastic head unit where the brewing takes place. 

The "vac" in the name gives away how it works. You snugly attach the plastic bucket on top of the carafe (it has a silicone ring gasket for an airtight seal), then pour your coffee grounds and hot water into it. Give everything a stir, wait a minute or two for the coffee to steep, then press the elevated button in the center of the bucket to activate a vacuum pump hidden within the head unit. That pump generates a 7-psi vacuum inside the glass carafe—just enough suction to draw the muddy water through the grounds, across a metal mesh filter, through a very small hole, and into the carafe, where it dribbles in as clear coffee free of sediment and bitter oils. (I should pause for a moment to clarify that the VacOne isn't a stand-alone coffee maker like an Oxo or Mr. Coffee drip machine. You'll still need a kettle to heat the water.)

The vacuum pump is battery powered, so there's a USB-rechargeable cell inside the VacOne's head unit. The company claims the battery will make up to 200 carafes of coffee per charge. That sounds right. I haven't had to charge my test unit yet; I just pulled it out of the box when it arrived and started using it, and I've made at least 100 cups with the thing during my two months with it. If you're worried you'll be stuck having to charge your cordless coffee maker all the time, don't be. A two-hour charge every few months should be fine. 

The analog gadgets that come closest to doing what the VacOne does are pour-over drippers with manual release mechanisms like the ones from Clever and December. Both of those let you decide how long the coffee spends in contact with the hot water before it's released through the filter and into the cup. The difference is that they rely on gravity to pull the coffee through a filter. The VacOne uses a mechanical air pump, which has a few advantages. For starters, you get a more complete extraction; the pump literally sucks the grounds dry. The fine mesh filter on the VacOne also produces a cleaner cup of coffee than a paper filter, with almost no cloudy sediment in the mix.

Probably the biggest advantage is how the VacOne handles the bitter oils that are the natural byproduct of coffee brewing. When you pour in the grounds and the hot water and stir it all up, you'll see a light brown foam form at the top of the mixture. That's the effect of gasses and oils escaping from the roasted coffee beans. That layer of bitter and acidic foam stays at the top, and when the VacOne pulls all the liquid out from the bottom, the foam comes to rest on top of the damp grounds. That effluvium doesn't get pulled through the filter. The resulting cup of coffee is pleasantly light in body, low in acid, and free of any strong bitter notes. I ran some tests comparing the VacOne's output with my Kalita dripper and an AeroPress Go, using the same roast on all three. The VacOne consistently made the best-tasting cup of coffee.

If the design of the VacOne looks at all familiar, it's because the same company sold a nearly identical product in 2019 and 2020 called the FrankOne. I also tested that brewer and found it had a few quirks—the circular filter came loose too often, and the ring gasket didn't always form an airtight seal inside the carafe. Those problems have been fixed in a redesign, and the machine has been relaunched under this new brand. It's available directly from the Vac Coffee website starting this week and will be at other e-retailers in June.

The lead designer and company founder, Eduardo Umaña, has been on WIRED's radar for a while. He's designed beautiful analog watches that we've featured before, and he invented a cute and fun table lamp that turns on when you whistle. Umaña is Colombian, and his cofounder Otto Becker comes from a Guatemalan family that's been growing coffee for five generations. The duo has also partnered with the former World Barista Champion Raul Rodas, also from Guatemala, to start a mail-order coffee subscription service for high-end roasts that will launch later this year.

I asked Umaña to give me the recipe he uses to brew coffee in the VacOne so I could try it myself: 20 grams of coffee grounds, 250 milliliters of water heated to 203 degrees Fahrenheit, steeped for 75 seconds. 

He also recommends using a very fine grind setting for the beans: the number 6 setting on the Baratza Encore grinder (WIRED's favorite grinder), which is very close to what you put into an espresso machine. If you don't grind your own beans, or if you have a grinder that doesn't let you adjust the grind size, you can use any bagged or canned “espresso grind” on the VacOne, which work well.

Curiously, using a finer grind really cleans up the brew. I had been using a larger grind (the number 20 setting on my Encore) like the size you'd typically use in a pour-over dripper, and I noticed the coffee coming out of the VacOne was a bit cloudy with sediment. I was surprised to see that moving to the smaller grind resulted in a perfectly clear cup of coffee that—more importantly—tasted better.

The machine also makes cold brew. I had difficulty getting a satisfying glass of cold brew out of the VacOne, but after fiddling with the grind-to-water ratio and the steep time (again, with Umaña's guidance) I arrived at a better drink. I tried 30 grams of coffee with 200 ml of water and let it steep for about six minutes. It came out light and bright; several notches away from the type of syrupy blasting agent you get from an overnight cold brewer, but still delicious and ready in minutes.

My biggest complaint about the VacOne is the cleanup involved. After a brew cycle, there are two pieces to wash, and one of them (the VacOne head unit) has a bundt-cake-like ring of finely ground coffee at the bottom. You can flip it upside down over the compost pail and gently whack the sides until the clumps of grounds come out, but you're still left with enough residue to require a few wipes with a paper towel and a run under the faucet. Your hands are going to get dirty no matter what. A smaller complaint is that the maximum amount of coffee you can make in one brew cycle is 14 ounces. This isn't an issue for me, since that's my daily limit. But if you have two or three coffee drinkers in your home, you'll have to work overtime.

At $89, the price feels right—especially with a generous 16-month warranty against defects. If the carafe breaks or the filter rips, you can buy replacements ($25 for a carafe and $8 for a filter), which is a friendly touch.

Every coffee enthusiast with a brewing setup—particularly a fancy coffee grinder and a nice kettle with temperature control—should consider adding a VacOne to their arsenal. It's smart, it's easy to use, and it makes a damn great cup.