The ultimate thermometer from Chris Young

For sous vide-like control of a smoker or conventional oven, Chris Young (ex-Fat Duck, coauthor of Modernist Cuisine & creator of the ChefSteps Joule sous vide circulator) has a new company, Combustion Inc, and a new product (as yet no name and not released, but should come out this year):

A wireless thermometer with 8 different sensors that can measure the temp of your meat from its center to its surface (making it a wet bulb thermometer), as well as the temp of the surrounding air. All wirelessly integrated with a base (which apparently has various predictive algorithms) and a charger that acts as a repeater (so up to 300m distance).

This is not just another Meater, but a potential game changer (imagine baggless sous vide like a combi oven, but in your smoker or conventional oven). He’s been answering questions about in on my r/CombiSteamOvenCooking group on Reddit, and if if there is enough interest I could ask him to come over here.

This video explains how this principle can be applied to conventional ovens (not using the new thermometer):


Interesting, subscribed, any idea on pricing?

Thanks for posting! Signed up (you should put your referral link since you found it). Will be curious on price as well, WiFi/bluetooth or both (hopefully) and water proof.

Also signed up, thanks.

No, he cryptically said somewhere between expensive and cheap. [snort.gif]

Good idea, added to original post. I could use $10 off lol!

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He said something about learning from the Joule Wifi experience so that he wanted something that just worked out of the box and didn’t need to be connected to a network (but maybe that is optional, I’m not sure).

I go by the rule of “it is only expensive if it doesn’t work as expected”.

Oh, I signed up. champagne.gif

It’s fascinating how complicated this stuff is, and how clueless we all are about how coooking food actually works. I’ve studied this stuff pretty carefully, and have the scientific background to actually understand it, and I’m still realizing I don’t really understand it.

Worth reading if you are geeky enough:

Although sometimes I think: Just throw it in the smoker and hope for the best! [head-bang.gif]

Interesting concept, but overall a bit odd to me.

The thermometer seems to be more geared towards internal temp cooking vs. “surface temperate cooking” that Chris espoused the virtues of in video.

I’m also curious as to how this will differentiate itself from the other wireless thermometers that are already out in the market. How different is this to other wireless probes like the Meater?

Do I need this, No, but I am also the guy with wireless tags monitoring my basement and wine fridge temperatures. So yes I need to have this

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I think the key is that you can measure both the core temp, the surface temp, and the ambient temp. So, for example, you can jump the ambient temp to speed up the cooking (cook a sous vide steak twice as fast) and stop it when your reach the right core temp without overcooking the outside of the steak or roast. Something you can also do with the $600 Anova Precison Oven, but not easily with many ovens that cost a lot more. If you follow the link to the Reddit discussionn, the surface temp is actually a lot more complicated than we might think.

I don’t have a Meater, but I think it only has two different sensors and it doesn’t operate as a wet bulb thermometer (correct me if I’m wrong).

A Clubhouse interview with Chris:

Hadn’t heard of the terms web bulb thermometer until today. As I understand it, it measure the ambient cooking temperature as well as internal temp? (Please correct me if I’m wrong). If that’s the case, probes like the Meater do that as well

No, sorry this is hard to explain, but I’ll try…

Wet bulb is the actual temperature the food is cooking at in your oven or grill (essentially its surface temperature). If you set your oven to 375°F, that is the ambient temp of the AIR in the oven (the temp measured by a standard thermometer), but that’s not the temp that the FOOD is actually experiencing. Just like wind chill or the heat index, evaporation of water from food (food is mostly water) cools the surface of the food, so the so-called “wet bulb” is the temp that results from evaporative cooling of the food (or the temp a standard thermometer would read if you covered it in a wet paper towel). Since water boils at 212°F, your food is never going to be hotter than that as long as it is sufficiently moist.

It’s not a concept you see much in cooking circles in the US outside of the BBQ community or professional kitchens, but it’s critical to understanding how things like combi steam ovens, where the controlled humidity affects evaporation from food and therefore the temp the food experiences (at 100% relative humidity, so no evaporation, the dry bulb = wet bulb temps, but at <100% RH the wet bulb temp will always be lower because of that evaporative cooling), which are common in restaurants (and more than the US in homes in Asia and Europe). It’s actually also critical to cooking in your standard oven or grill too, but we just don’t realize it when we crake it up to 375°F! The famous temperature “stall” in BBQ cooking that was always a puzzle to people is actually caused by this.

There’s a complicated relationship between the two temps and humidity, as you can see from this chart (courtesy of Scott H from Anova):

From the perspective of combi ovens, here’s a good article on the subject (Scott was a director at Modernist Cuisine, there’s a whole chapter on this subject in the Modernist Cuisine cookbook):

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I’m curious about this product too. I doubt it could be used on a grill without risking damage though. The exposed part would see temps far higher than a typical oven. But, it would appear to be great for reverse searing and just pull the probe prior to the sear, where temp concerns are done.

To quote Chris Young on Reddit:

“The sensor tube is stainless steel, the handle is ceramic. The timer is covered in silicone (easy to clean off goo).

The front part of the thermometer is limited to 105 °C / 220 °F because of the battery and microprocessor (limit of reasonable technology right now). The back half of the sensor tube and handle are good to 300 °C / 570 °F, although they can handle flare-ups and brief excursions above that.

Probe is dishwasher safe and should be usable in a deep-fryer.

So, while it’s not indestructible, I think durable.”

It has been 25+ years since I took any thermodynamics or heat transfer classes so I could be off base here but a couple of thoughts…

This is not a wet bulb thermometer or even an approximation of one. A wet bulb thermometer is wrapped in a damp clothe over which air flows - that is necessary to measure the cooling of evaporation. Most of this thermometers probes are inserted inside the food being cooked so by definition cannot have any airflow and it would appear that any external temperature sensors are not wrapped in a damp cloth either.

That’s okay because the wet bulb temperature is somewhat irrelevant - at least to anything other than the surface of what is being cooked (Yes, technically it matters but hear me out). The only part of the food being cooked by convection (where the wet bulb temperature matters) is the surface of the food, the rest is being cooked by conduction as the heat transfers through the food. Basically you have a temperature gradient within the food with the center being the coolest and the surface being the hottest - and if left in the oven long enough it will reach a consistent temperature throughout. This happens fairly quickly with sous vide because heat transfer from water is much more efficient than from air. So, back to the temperature gradient, if you know the temperature of the surface of your food, you have a pretty good approximation of the wet bulb temperature. Based on empirical data, we have reasonable approximations of heat transfer through different food types and if you have the core temperature from the probe, you should be able to predict fairly well when the food will reach the desired temperature. Given that they have 8 thermocouples in this probe, it would seem that you can get a clearer picture of the temperature gradient. I suppose that would be helpful on a large roast or a Boston Butt but am not sure how valuable that would be for say a 1" thick steak.

Maybe I am missing something but it appears to me that the difference between this and the Meater is that this allows the cook to measure surface temp in addition to ambient and core - so approximate wet bulb temperature but only after the surface has reached equilibrium. I guess I don’t see how it gives me ‘sous vide’ like control. Thinking this through does make think that a combination temperature/humidity sensor would really be what you want since the wet bulb temperature is a function of those two values.

Thanks Kevin. Interesting.

Actually it is a wet bulb thermometer. Since, as you note, it has 8 temperature sensors, it measures the food at multiple points between the circulating air in the oven, the food surface, and various points between the surface and the center of the meat. The surface temperature of the food, which is cooled by evaporative cooling, is by definition a wet bulb temperature, and more accurate/relevant than a separate wet bulb thermometer, which will not change as the food surface gradually dries out and the temperature changes. A proper wet bulb will not change because it doesn’t dry out (the majority of wet bulb thermometers you can buy calculate the wet bulb temp from the humidity and dry bulb temp, and there is no water involved) or if it really is wrapped in a wet towel it will dry out at a different rate. What that means is that the temperature the food is experiencing actually changes over the course of the cook, even though the temperature of the oven doesn’t change (anyone familiar with the famous “stall” in BBQ cooking has seen this).

By the way, I have an combi oven with a wet bulb thermometer in it, and there is no damp cloth involved (it is water cooled). That is an example that is used to explain the concept to people, not necessarily how wet bulb thermometers are actually used (as I said most of them are not actually water cooled).

Finally, how this is valuable is in two ways. First, knowing the wet bulb temperature of the food allows you to do things like sous vide cooking, possibly in places that you couldn’t before, like your conventional oven (the temperature of a water bath is equal to the wet bulb temperature of the food in a bag in the water bath because the inside of the bag is at 100% relative humidity and therefore the wet bulb and dry bulb temps are equal). Second, apparently this thermometer includes software that can measure the behavior of your oven and food, model it and predict when the cook will be completed, and even how long it should be rested for. We’ll have to see how useful that is, but I can imagine if it is accurate, it could be very convenient. For your example of a 1" steak, it would make doing reverse seared steak more predictable.

It would be really nice if it could actually control the oven (apparently that is something they are working on).