The last time I did a major testing of sous vide equipment, we were still in the early phases of the home sous vide market, with three devices leading the vanguard. These days there are a half dozen more of varying quality, including updated WiFi- and Bluetooth-enabled, app-powered versions from Anova (currently the one I personally use the most frequently) and Nomiku.
The Joule is the new kid on the block, and it is easily the most hotly anticipated piece of kitchen hardware for cooking nerds that I've seen in a while. It's made by ChefSteps, a Seattle-based company that made its name producing high-quality cooking videos with a smart, modernist slant (Chris Young, the founder of ChefSteps, was a lead author of Modernist Cuisine, and several Modernist Cuisine alumni came along with him, including Grant Crilly). Given how many sous vide recipes they feature on their site, it makes sense that their first foray into the world of hardware would be a sous vide device.
The philosophy behind building it was simple: Most modern sous vide devices are based on the same technology, but Chris and the ChefSteps team decided to re-engineer a sous vide circulator from the ground up, incorporating technologies designed to make it more compact, more efficient, and longer-lasting.
After a lengthy build-up, the Joule has finally been released and is shipping now, at a price of $199. I've been testing a pre-production beta version of the unit for several months, and an actual production-line model for a few weeks. Here are my thoughts. The news is (mostly) great.
Functionally, the only thing that a sous vide cooker really needs to do is heat a volume of water to a precise temperature and hold it there. And unless you're a professional cook or caterer, most of the time you won't have the need to heat up more than a few gallons at a time. Every sous vide cooker on the market that I've tested accomplishes this. The real differences come down to design, features, and basic specs. Here's what the Joule does right, in order from most to least useful.
It's Tiny (and Pretty)
The Joule is only 11 inches tall and just under two inches in diameter. That's small, especially compared to competitors. I remember thinking how compact the Anova WiFi felt when it came out a couple of years ago (earlier sous vide machines were clunky behemoths), and while it's still on the smaller side, the Joule is tiny by comparison—volume-wise, it's less than half the size of any of its competitors. More than any other feature, this was the one I found handiest.
I have a large collection of sous vide cookers and I store most of them in upper cabinets inside plastic tubs. That means pulling out a stepladder and reaching into a cabinet every time I want to cook. The Joule, on the other hand, is slim enough that it fits in a silverware drawer. It may seem like a minor improvement in convenience, but if you cook sous vide more than a couple of times per month, it makes a difference.
The Joule is also aesthetically appealing, with a solid white polycarbonate casing and a silver button on top. Fans of old-school iPods will like the color scheme and details.
Its Magnetic Bottom is Awesome
This is another game changer. Most sous vide devices rely on a clip or a clamp to secure themselves to the side of a pot or other vessel. The Joule has a metal clip too, though not a great one (it's not as secure as Anova's clamp, and unless you opt for the upgraded accessory version, it will not fit on anything wider than a pot, like a cooler or a Cambro container), but its most useful form of attachment is its magnetic foot. Just stick the Joule into any cast iron, steel, or other induction-ready pot, and it'll clamp itself down with 6 pounds of force. That's plenty to keep it perfectly stable while cooking. It's an ingeniously simple solution to what was previously a perennial problem.
It Barely Needs Any Water and Makes Little Noise
The Joule uses a brushless motor to drive an impeller that sucks up water through an inlet at the bottom. It then draws the water up through its heating element, and spits it back out through a small outlet a couple of inches up the side of the device. The neat part is that the outlet does not need to be submerged for the unit to work.
In fact, because the magnet allows the unit to rest directly on the bottom of a pot, you only need an inch and a half of water to run the circulator. That's less than any other sous vide circulator on the market. Devices that clip to the sides of the pot require a pot large enough to offset the imbalance that creates. The Joule can stick to the very center of the pot, which means that even your smallest saucepan is now a viable tool for sous vide cooking. That's good news if you only have, say, a half dozen eggs to cook.
ChefSteps claims that their motor and impeller are designed to eliminate cavitation (the formation of small bubbles underwater that can make noise as they get sucked through the system). The early beta-version of the Joule that I tested had trouble living up to this claim, but the actual production-line model has proven to be perfectly silent for the several weeks I've been using it. I also like that the impeller is removable (unscrew the magnet, pull out the impeller with the tine of a fork) and made of plastic, which makes for easy cleaning.
The Joule is the only model on the market that's fully waterproof, which means that even if you accidentally drop it into your water bath, it's no big deal. Just fish it out and keep going.
It Has a High-Tech Heating Element
Unlike the twisted coil heaters found in other sous vide machines, the Joule uses a device called a thick-film heater—essentially a cylindrical heating element with high thermal power density that's embedded in a polymer. This gives it far more heating power in a much more compact space. It also has fewer odd shapes and crevices, which means easier cleaning and less scale build-up over time. The Joule also efficiently diverts heat generated by internal moving parts (like its motor) back into the water, improving its efficiency.
For me, the main attraction of the heating element is its contribution (or lack thereof) to size. The ChefSteps team managed to pack a ton of power into a really tiny package. The Joule draws 1,100 watts of power—as powerful as the Sansaire, and more powerful than the Nomiku (1,000 watts) or the Anova (900 watts). In practical terms, that means that it will heat up your water to cooking temps just a little bit faster and you'll be able to maintain a slightly larger bath, though not an enormously one. In my tests, it was able to heat up two gallons of water from room temperature to 140°F a few minutes faster than my Anova. Not a huge deal—if you plan right, you'll be prepping ingredients during its heating period anyway.
In my tests, it easily maintained 15 liters of water at 140°F in a plastic Cambro container—that's large enough to cook a couple legs of lamb or a half dozen racks of pork ribs simultaneously. Their spec sheet says it can heat up to 20 liters, or 40 liters in a well-insulated container.
The Display and Interface
This is the only complaint I have about the Joule, and it could be a deal-breaker for some folks: The Joule has no display other than a single glowing LED, and no on-board controls other than the "off" button on top. In other words, it must be controlled by an app running on a separate device. Without your phone and an internet or bluetooth connection, the device is nothing more than a pretty piece of modern art.
This is both a blessing and a curse. The lack of display is one of the reasons they were able to make the Joule so small and light. Presumably, it also makes the unit a little more robust (a basic rule of hardware being that the more parts you have that can break, the more likely it is that one of them will). But it's the only device in my kitchen that requires me to not only own another device (my phone), but also to download an app, sign up for a service, and give out my email address and personal information to a third party, all just to be able to turn it on.
To be fair, because I already had a ChefSteps account, the setup was fairly painless and I was up and running in a few minutes. But I've also gotten a few negative anecdotes from early users who didn't have quite as simple a time getting set up. I also ran into a snafu when my internet went down a couple of weeks ago, though I was able to quickly pair the circulator via Bluetooth once I realized what the problem was. It was still frustrating.
From a convenience standpoint, it can be hard to get used to. I typically don't touch my phone while I'm cooking—I don't like to leave it on the counter where it might get spilled or splashed on, and I also don't like to fish around in my pockets, given that most of the time that I'm cooking sous vide, I'm handling raw, slippery meat. That said, I understand that I might be the minority in this regard (and seeing as I provide recipes and guides for the Anova sous vide app, perhaps a little hypocritical too).
Regardless, once it's set up, the app is robust. It allows you to set the cooking temperatures and times in two ways: There's a manual control that lets you punch in a number (anywhere up to 194°F/90°C), or you can navigate to individual recipes and guides. In keeping with all the photographs and videos that ChefSteps has produced, the guides are gorgeous, and feature step-by-step videos that walk you through picking a temperature, and then seasoning, bagging, cooking, and searing your food, and it turns your Joule on and off when necessary.
The Potential Upside: Voice Control Coming Soon
There's some good news to this one downside: ChefSteps is in the process of introducing voice control to the Joule, via a skill on Amazon's Echo device. With the skill installed, all you have to do is say, "Alexa, ask Joule to set the temperature to 140 degrees," and your circulator should kick on.
This may give some security- and privacy-conscious folks (my wife is a cryptographer, so I'm included in that group by default) some pause: you're now releasing information and running it through two completely different services (Amazon and ChefSteps) just to make dinner. Granted, that information may not be much more personal than what kind of meat you like to cook and what temperature you like to serve it at, but public figures have been skewered for those very things.
Am I going to start seeing emails and Amazon recommendations for sponsored meal kits that include the proteins I most commonly eat? That seems like an obvious next step,* and I'm not sure it's one I'd welcome with open arms. I like to share my meals when I want to and with whom I want, I don't like the idea of people peering in at my dinner table.
* Frankly, I wouldn't be surprised if we at Serious Eats started designing recipe kits for sous vide devices!
Only One Joule Per Device
I have multiple sous vide cookers at home and while I typically only use one at a time (other than when testing recipes), there are times when I do want to have two different devices set at two different temperatures, especially around the holidays.
Unfortunately, currently there is a one-Joule-per-device limit. That is, if you want to run two Joules at a time, you'll need to install the app on two different phones or tablets. ChefSteps says that multi-Joule functionality should be coming in a future update, though they do not say exactly when.
So Should I Get It?
It's a solid machine, and in many respects—size, power, efficiency, and features—the new standard on the market. But the lack of display and on-board controls is going to be a deciding factor for many folks. At this stage of the game, I'm going to come out and recommend both the Anova and the Joule as equally attractive tools designed for slightly different audiences. Choose whichever one suits your needs best—you can't really go wrong.
Note: This review and testing was written entirely independently of the Serious Eats ad sales team, and any products mentioned or featured in this guide that may currently or in the future advertise with Serious Eats is purely coincidental.