The Combustion Predictive Thermometer Has Eight Sensors to Formulate a Cooking Time

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Credit: Amanda Blum

Wireless thermometers aren’t new. For years, cooking enthusiasts have had access to units that could be read remotely via an additional unit you carried on you like a BBQ beeper. Highly imperfect, they were notorious for having a small range, and for the cords between the probe and the base burning out. The latest generation of wireless thermometers have ditched the cords altogether. New cordless probes can go more places, and don’t need a remote unit—you just receive information in the app on your phone, all handled via Bluetooth. They’ve also added AI to the mix, with predictive cooking times. I’ve tried a few of these systems lately, and so far, the Combustion is the most reliable and consistent, but still wobbled on a few occasions. 

Solid hardware that holds a charge

All of the systems I tested have the same underlying setup—you have a Bluetooth receiver that also serves as a charger for the probe. The receiver needs to be relatively close to the probe, and then your phone also needs to be in range of the receiver. Theoretically, the Combustion’s range is 660 feet. However, as we’ve all learned over the last 10 years, Bluetooth and wireless signals can be interrupted by obstacles like large appliances, the materials your home was built with, and your microwave. For that reason, Combustion also created Bluetooth extenders that look exactly like the receiver/charging base. 

Right off the bat, I liked that the receiver and charger were innocuous and small. The receivers charge via USB-C, which I also appreciated—other units I tested used batteries. The units came with enough charge to get through setup, and I haven’t had to charge any of them since, despite using them extensively. Combustion says they last six months, and one month in, there’s no sign of needing to recharge yet. 

As probes go, these are quite beefy. I checked in with a few nerdy BBQ friends to ask about the general impression of these new AI probes and the main complaint was that compared to regular wired models, these probes just left too big a hole in the protein.  This is a valid complaint: it felt a little violating when putting the probes in, although I didn't really notice it in any of the meals when dining.

Great Bluetooth connectivity

I tested a few different thermometers over tons of different cooking experiences, and tested them against my super-reliable ThermaPen, which had been calibrated. I made salmon in an oven, a spatchcock chicken on the grill, a sous-vide turkey breast, a prime rib in the oven, and both a chicken breast and a thick-cut pork chop on the stovetop. Yes, sous vide: one serious advantage of a wireless probe is that it can be sealed in a bag. You shouldn’t submerge the entire probes in water themselves—Combustion sells a clip to keep them partially un-submerged.

In all but one of the experiments, the Combustion stayed connected via Bluetooth. Even though I had two extenders (the display unit is an extender, in addition to the actual extenders they sell), I never needed to use them.

A simple but direct app experience—but unpredictable AI

Setup was quite easy—you open the app and take the probe out of the receiver; the app sees it almost immediately and lets you set up your first cooking experience. You can set a goal temperature—that’s the basis of the predictive cooking time. It’s worth noting that other apps, like Meater, had a much more in-depth app experience, where you could choose what kind of protein you were making and it would give a range of suggested temps. That's a useful but not necessary feature that I’d appreciate added to the Combustion app—in most instances I prefer to choose my own temperature. Once you fire it up, Combustion has a pretty interface that tells you the core, surface and ambient temperature of the environment the probe is in, as well as some molecular data on when the cook started, how long it’s been going, and when it should hit your goal temperature. Eight sensors in the probe measure along the length and use those temperatures to form the predicted cooking time.

That third metric, the predictive AI, was the least useful data, but this was true across all the products I tested. It takes a while for the predictive time to come on board; it changed often; and it was just plain wrong most of the time. The Postmates app is better at predicting when my food will arrive. There’s some science behind why this is hard—even with as many sensors along the length of the probe as there are, food doesn’t heat evenly, there are factors like the shape and size of the food, the fact that meat actually does sweat, and sometimes stalls out during cooking. 

While there are instances, like while grilling, that I might have enjoyed the predictive feature, it didn’t detract much from the experience that it was wrong. I might, over time, have come to trust it, but like most people I frequently checked the temperature on my own to gauge when food would be done, and in most cases, recipes or experience gave me a good idea. 

Close (but no cigar) temperature readings

The other place where all probe thermometers fell apart was on giving me an accurate temperature reading—but to be clear, it was never off by more than a few degrees, which isn’t critical, and I suspect the probe was giving me a calculated mean of temperature through some algorithm, rather than the simple temp read the ThermaPen uses. If I hadn't been checking against a control thermometer, I'd never know it was off.

An expensive but fun tech toy for the kitchen enthusiast or deeply lazy cook

A wireless thermometers go, Combustion far, far exceeds the older generation of remote “beeper” wireless thermometers. Of the new generation of probes, it’s the best I’ve tested so far. The Combustion can receive updates via Bluetooth, so the AI may get better. The app works well, and will probably get more features in the future. The Combustion stayed connected throughout a multitude of locations, experiences and proteins, without even requiring the extender, but it’s nice to have the extender, just in case. In particular, the ability to throw a probe into sous-vide food is a real bonus, and as an inherently lazy cook, I absolutely love being able to monitor food from afar. 

Do I love it enough to pay $149 for a thermometer? If you’re someone who is only ever going to buy a $30 thermometer, this is an unlikely buy. If you’re someone who values precision enough to grab the commonly recommended digital thermometer, the ThermaPen at $100 or so, then another $50 might not seem like a big stretch. This would be a great gift for a BBQ enthusiast that you’ve exhausted ideas for, or a nerdy cooking friend. The Combustion was, in addition to everything else, a lot of fun.