FAQ

THERMOMETER BASICS

How is it different than other wireless thermometers?

The Predictive Thermometer has 8 sensors. Other wireless thermometers only have one or two. Those “extra” sensors let us figure out the effective size of the food, how evenly it’s cooking, and how things are changing. That means we can quickly and accurately calculate how long the food should cook and how long it should rest to be perfectly done.

Why should I care about the surface temperature?

Surface temperature is the secret to consistent, precision cooking. That's because the temperature at the surface of your food is the temperature the rest of the food feels. It's nowhere near as hot as the surrounding oven, and that's because your food sweats. As it does, the evaporating juices cool the surface to a lower cooking temperature. How much? It's hard to say, and that's why we measure at the surface. (By the way, we’re the only one who can.) 

By measuring surface temp, you can adjust your oven or smoker to the control the true cooking temperature, bringing a precision to your cooking that was previously only possible with sous vide.

We love surface temperature cooking so much that Chris made a video about it before we even started building the Predictive Thermometer. (Thankfully, we managed to get rid of all those wires.)

Don't I only need to know the temp at the center?

Until now, that was the only thing you could measure. For perfect results, you want to measure that and more. The Predictive Thermometer measures the center (core) temp, the surface temp, ambient temp, and everywhere in between. 

What’s more, our extra sensors (8 total!) allow us to find the center, even if you miss it. This often happens with compact food like a filet mignon or with irregular food like a whole chicken.

All wireless thermometers have a minimum insertion depth (ours is 2in/50mm). If our tip sensor ends up past the center, the lowest reading from the other internal sensors reveals the true core temp.

In that situation, any other thermometer would misread the temperature, making you think the food is overdone when the center is still underdone. Tragedy! 

With our True Core technology, near misses are not misses. In fact, we recommend you push the tip a bit further than the visual center. We'll find and instantly report the lowest temperature so you can be totally confident it comes out just right.

Anything else?

•Our thermometer is a lot thinner (a 36% smaller cross-sectional area than any other wireless thermometer). Easier stabbin’. Smaller holes.   

•Wireless is designed to simply work, without the fussy “pairing” process you get with most smart products. 

•With the Combustion Display you don’t have to depend on your phone or rely on your internet provider. (Though we also have a very nice mobile app). 

•Unlike other wireless thermometers, it can give you an instant read. (Time-to-read is less than 4 seconds–about the same as the dedicated instant-read thermometers most professional kitchens use.)

•Quickest read time. Many times faster than other wireless thermometers. (By the time you see their reading, it's more than 30 seconds later!)

•Automatically finds the lowest internal temperature, giving you an instant and accurate core temp even if the tip misses the mark. No other thermometer can do that. 

•Highest temperature rating (up to 575 °F / 300 °C) available.

•Unlike other instant read thermometers, it has 8 sensors, so you get the full temperature from edge-to-edge.

CAN IT BE USED IN A ___?

Can it be used in an oven?

Of course.

Can it be used on a stovetop?

Obviously.

What about induction?

No problem.

Can it be used on a charcoal grill? A gas grill?

Yes and yes.

Can it be used in a smoker?

Yes, brisketeers, a million times yes.

Can it be used in sous vide?

That's the plan, but we can't recommend it quite yet. Need more data. Full explanation below.

Can it be used in a rotisserie?

You bet your bird it can.

What about an air-fryer?

Yes, indeed. That’s basically a convection oven and since you asked: those are also good.

Can it be used in a dutch oven?

It depends. It won’t harm the probe, but with the lid closed, you won’t get a signal. (Could you check-in by leaving the probe in the pot roast or whatever—and occasionally taking the lid off? Sure.)

Can it be used in a microwave?

No way! Unless you like explosions. That’s going to void the warranty on everything and everyone around.

Can it be used in a trivection oven?

Apparently not. The meshy screen that keeps microwaves from escaping also keeps Bluetooth signals from escaping. Also: microwaves! See above.

Can it be used in a pressure cooker?

Sadly no. The pressure raises the boiling point of water to 248 °F / 120 °C, which means the water inside the food can’t keep the electronics in the tip cool enough. See below.

Can it be used in a “broaster”?

No. Sorry, broasterphiles.

Can it be used in a nuclear reactor?

Pictures or it didn’t happen.

SPECS AND TECH

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Combustion Display Specs: Shows Core, Surface, Ambient Temps plus target temp and "ready-in" prediction

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What is the max operating temperature?

575 °F (300 °C) above the minimum insertion line, including the ceramic handle.

212 °F / 100 °C at the tip (the pointy bit) to the minimum insertion line.

Always insert your thermometer at least 50 mm (1.97”) into your food. Don’t worry, it’s clearly marked.

Followup question: what’s up with that?

The water content of the food protects the tip of the predictive probe. It won’t go above boiling if there are any water molecules left. Science! Your pork butt protects the probe and the probe protects the pork butt. That’s why we put the more delicate electronics and battery in the tip.

Followup question: also, what about the plastic handle?

IT’S NOT PLASTIC. Sorry about the yelling. Despite the friendly color, it’s actually solid ceramic and nearly indestructible. It can handle flare-ups, falls, and the sanitizing cycle in your dishwasher. We poached it in liquid nitrogen, and it didn’t even flinch.

[Note from engineering: please don't do that anymore.]

Display or app, I’m confused?

Some people don’t want to use their phones in the kitchen. If you’re cooking something messy, your phone is going to get sticky or saucy or both. The display keeps it simple — it’s water-resistant and easy-to-clean. It’s big, bright, backlit, and easily readable. The screen won’t shatter when you drop it. It goes weeks between charges. It can also be used as a simple timer, which is handy. And there’s less chance of getting distracted by a video of a baby sloth playing with a xylophone.

What’s the advantage of using the phone app?

A) There will be lots of extras in the app, including pretty charts that track the temperature of your food anywhere along the thermometer. We interpolate between the 8 sensors with, yup, math, so we can show you how evenly (or not) your food is cooking. It’s like x-ray vision to see inside your food as it roasts.  

B) You can manage even more thermometers at once, and give them nicknames.

C) It’s not one or the other, you can use it and still use the display. In fact, the display automatically relays the signal so that you can roam further from the kitchen.  

D) The display timer cannot show you videos of adorable baby sloths.

What’s a good nickname for a thermometer?

“Mr. Pointy” is always a classic. ASOIAF fans might prefer “Needle.” You could go descriptive like “Meat Only.” Or get reductive with the color of the silicon band accessory (coming soon): “Red,” “Blue,” etc (they come in different colors, you know). You could name one “Jimmy Witherspoon.” Whatever suits you.

Can I use it as an instant-read thermometer? Can I use the display like a basic kitchen timer?

Yes to both. A smart product doesn’t always need to show off. And there’s countless reasons to time things, even when nothing’s in the oven. You could be timing your proofing. You could be timing a dessert chilling. You could be timing your nap. We’re not here to judge.

How does it predict when my food will be perfect?

There’s a lot of math involved and the computers do it for you. Our predictive engine runs the numbers, compares readings all along the thermometer and uses our predictive algorithm to tell you exactly when your food will reach the perfect temperature. That’s the big number that shows up on the display (or app). 

Prime rib, baked swordfish, different foods, of different sizes, different density, different temperature targets, with smaller or larger windows of done-ness — it doesn’t matter, you never have to guess. That’s kind of the whole point.

How does the wireless stuff work?

Most smart devices are kind of stupid. Sometimes they connect. Sometimes they don't. Often they disconnect. We’ve made it simple. Our stuff skips the "Bluetooth pairing" process and broadcasts temperature data in the open. So things just connect quickly and work consistently. Fair warning, your nosy neighbor might discover when your pork chops are going to be ready, and come looking for extras. Unfortunately for them, there’s no such thing as extra pork chops.

What’s the wireless range?

It depends. In a wide-open space, the Bluetooth signals will travel 300 feet (90m) or more, but when the thermometer is locked inside a smoker, or if you live in a solid concrete building, the signals don’t go as far. In practice, we can usually get 60-feet away (20m) and still keep an eye on how things are going. 

The Combustion Display was designed to help out by listening to nearby thermometers and then repeating their signal at the maximum power legally allowed by the FCC (or your local regulatory agency). 

Just to be safe, the thermometer logs all the data. If you wander out of range all of the data is forwarded along as soon as you wander back.

More about wireless signals below.

How long does the battery last?

Battery life:

With a full charge, the Predictive Thermometer works for 24 hrs in cooking mode, or 5.7 hrs in instant-read mode.

A thermometer out of its charger is in instant-read mode by default. It changes to cooking mode when you set a target (cooking to) temp.

The Predictive Thermometer can remain in standby-by mode for 14 days on a full charge.

The thermometer goes into standby mode when it's in the charger (sleeve) and the charger is not connected to a USB-C power source.

Recharge time:

The thermometer recharges in about 10 minutes.

The display battery charges in 80 minutes and is good for over a month per charge.

Is the battery safe at high temperatures?

Yes. The Predictive Thermometer uses an LTO (Lithium Titanate Oxide) battery, which is very stable. Much safer than the Lithium batteries you’re used to (Lithium Ion or Lithium Polymer). The LTO survives up to 105 °C (221 °F) and will just break if you get it much hotter. Since it’s tucked away inside the thermometer, the water content of the food keeps it safely below the boiling point (100 °C/212 °F).

What if I need multiple thermometers?

The Combustion Display (aka "Timer") can manage up to 4 thermometers simultaneously.

What kind of sensors are used in the thermometer?

That’s not a frequently-asked question. Anyway, each thermometer has 8 precision high-temperature thermistors and IC temperature sensors. Sensors in the tip (inside your food) measure temperature to within 0.2 °C.  Sensors in the handle end (built to withstand higher heat) measure to within 1 °C.

What’s up with sous vide?

For the moment (and this could change rapidly) we can't recommend using the thermometer in sous vide. 

We have to re-evaluate the vacuum-resistance (and thus sous vide readiness) of the main seal. 

Don't fret! We think it's going to be fine, we're just not 100% sure at the moment, so we're doing some extra-strenuous testing. We'll let you know soon.

ALL ABOUT PREORDERS

Where’s my order!?

That’s the number one question this holiday season. If you haven't received a happy little email* from us saying "shipped!" then your order has not yet left our warehouse. 

Shipping and deliveries are very complex at the moment, so instead of trying to keep everyone updated by email, we’ve created a special shipping section that answers all of your shipping/delivery questions as best we can, with the most current and accurate information we have available.

Everything is subject to change at a moment’s notice and has done so several times already.

*Some customers have missed notification or update emails. This is usually because they used a different email when ordering. If this happened to you, contact: orders@combustion.inc (include your order#).

What's taking so long? Why the delay?

The standards (and expectations) we set for the Predictive Thermometer presented some unique design and manufacturing challenges. We're putting a bunch of sensitive electronics in a very thin steel tube that needs to be watertight while shrugging off extreme thermodynamic changes. It's kind of like building a tiny submarine; only we’re building thousands of them.

On top of this, we faced an almost-comical number of random complications. An inconvenient market-wide microchip shortage. A global shipping crisis. Intermittent regional covid lockdowns. National holidays. Local import/export rule changes. And so on. 

Combustion’s engineers used each of these delays as opportunities to refine and improve the final device. In effect, you’ll be getting 2nd-gen hardware instead of 1st-gen. Yes we're delivering behind schedule, but it will be even better than we originally hoped. 

Our early customers have been wonderfully patient through all this. Thank you all. We're looking forward to making the wait deliciously worthwhile very soon.

Can I make changes to an existing order?

Sure thing. We’re a small company, so for now you’ll have to deal with an actual person instead of a bot. Hope that doesn’t make you too uncomfortable. Any changes you need on your existing order, contact orders@combustion.inc. We’ll get it taken care of.

What if I need to change my shipping address?

That happens sometimes with preorders like this. Across town? Easy peasy. New city or country? Trickier, but doable. Either way, write us here: orders@combustion.inc  (And include your order ID number, please. It’s totally the first thing we’ll ask).

What if I need to cancel my order?

You may cancel an order for a full refund anytime before it ships. That’s part of the whole preorder deal. Contact orders@combustion.inc

For full, lawyer-y details, see our refund policy.

What are the terms of the warranty?

No worries. You’re covered for 24 months (two years) against any hardware defects or malfunctions.

Full warranty page for you barrister-types.

Will it ship to my country?

For preorders, we will be shipping to the following countries:

United States 

US territories (Puerto Rico, Guam, and the US Virgin Islands)

Australia

Canada

EU and EEA Member countries

New Zealand

Switzerland

United Kingdom

For shipping outside of the USA, our international shipping partner Passport will be on-hand to answer any international tracking or tax questions.

If we aren’t shipping to your country yet, let us know by taking this quick survey.

What about Iceland?

We are shipping to Iceland DDU (delivery duty unpaid). Icelanders probably already know this, but that means you might have to pay additional taxes on arrival instead of paying them all in advance. Does that mean you pay more duties than other EEA members? Probably not but it’s possible. Þetta Reddast!

What about duties and taxes?

No surprises! Nearly all (looking at you Iceland) Combustion Inc. products are shipped Delivered Duties Paid (DDP). That means everything-taxes, duties, and import fees-are calculated and pre-paid at check-out. 

Orders@combustion.inc will get it sorted out if everything doesn’t go exactly to plan.

What is your return policy?

Returns will be accepted within 30 days of shipment for a full refund of the purchase price. Shipping costs and duties will not be refunded. Usual disclaimers apply (return it in the shape it came in, no funny business, and so on). 

The full legal policy is here, but our general rule is: if you’re unhappy with it, we’ll take it back. No hard feelings.

Why can’t I buy just the thermometer?

The Predictive Thermometer + Display were designed to work together to give you the best possible cooking experience. That’s why we’re offering them exclusively as a set for now. 

Hey, we love our phones, too. But phones depend on phone companies, internet providers, app stores, phone batteries, and so on–stuff we can’t control. The Combustion Display doesn’t need any of that. Everything works straight out of the box. No fussing, no mussing, just cooking and eating. 

Why can't I buy more than 2?

We’re still limited by supply (the great chip shortage) and want to be fair. We’d rather more people get a chance at it. Also, we know from experience that some unscrupulous types may try to buy a large number at a discount and scalp them on Amazon. Not cool.

 

ALL ABOUT WIRELESS

Why Bluetooth? What’s Bluetooth? How’s that work?

Bluetooth (aka BLE) is a low-power radio signal around the 2.45GHz band. It’s a very power-efficient way to transmit small data packets over a short distance.

This bandwidth is the area legally allowed for consumer products, so there’s a lot of competition for radio waves. It overlaps with what most WiFi uses. 

Curiously, it also overlaps with the radio frequency of microwave ovens (at a much lower power; a 700 watt oven is 35,000 times more powerful than Bluetooth 5).

The main advantage of using Bluetooth is that it requires so little power. Perfect for us because the battery inside the thermometer is necessarily tiny. If we put a WiFi transmitter inside a thermometer, our battery would only last minutes instead of hours.

Because it’s a tiny radio transmitter, it’s going to have some of the same issues that other transmitters and receivers have (physics!). Certain types of material are not radio-friendly (see below). 

Unless you live in a straw hut on a tropical island, there will probably be places in your home that have bad reception. Just like you get “dead spots” on your mobile phone, or places in your house where WiFi struggles.

What makes our wireless setup different? Is it reliable?

The most common complaints we’ve seen about competing wireless thermometers are signal reception problems and initial setup problems. It’s super-aggravating to disconnect in the middle of a cook. Tie that to creating an account or configuring a WiFi set-up and suddenly you’re dealing with sign-ins and passwords and electronic handshakes every time you lose signal. No thanks. 

We’re not immune to signal loss or disconnects (we are still bound by physics, after all), but we’ve done everything possible to minimize the annoyance it can cause.

First, we’re transmitting at a much higher power because we use the latest Bluetooth 5 chip for our radio. We also optimized the antenna design on both the Predictive Thermometer and Display to get the best performance for the minimum power—our design is very close to the theoretical limit of efficiency. 

Most importantly, our software is designed to work around interrupted signals and occasional disconnects. When the signal is lost, your Combustion Display (or app) automatically  catches up on all the data as soon as it’s back in range. So momentary signal-loss is automagically not-a-problem. 

With the Predictive Thermometer, there’s no sign-ins or passwords or accounts. You don’t ever have to login to use it – that means you don’t have to log back in - EVER.

What things are bad for Bluetooth signals?

Effective Bluetooth range is quite dependent on the environment. The ideal set up is to have a clear line of sight (LOS) between the antennas.

Here’s some of the things that commonly block or hinder signals:

Metal enclosures block radio transmissions, including Bluetooth. The thicker the metal the worse this will be. For smokers and grills, the vent holes tend to be where the signal escapes; if you close things up tight, any signal will struggle to escape. 

Foil! Wrapping the thermometer inside of a foil shield will keep the signal inside. So if you’re protecting a turkey, be sure that the handle of the thermometer is outside of the foil.  

Water, in general, muffles Bluetooth signals. Being submerged in sous vide will greatly reduce the Predictive Thermometer’s effective range, especially if the water is in a metal pot. For best results, sous vide in a plastic container. (Note: we are currently recommending against using the Predictive Thermometer for sous vide, but that’s likely to change soon.)  

Human beings. On a related note, people are (as one of our engineers put it) “big bags of water.” Standing between the thermometer and the display can partly block the signal, especially if you eclipse the view between the antennas.

Concrete or masonry walls or other obstructions between the thermometer and the receiving device—display or app—will limit the range a lot. Radio waves kind of jiggle through obstacles and brick doesn’t jiggle. 

Trivection oven glass has a mesh screen just like a microwave – because it includes a microwave (that’s the part that makes it “tri”). The mesh that keeps microwaves inside the oven also keeps Bluetooth signals in – they’re almost the same exact frequency. 

Reminder: never use your thermometer in a microwave! Metal and microwaves don’t mix. Particularly when that metal is our antenna, which is optimized to absorb energy at that particular wavelength - the results will be pyrotechnic and will definitely void your warranty.

What can I do to get a better Bluetooth signal?

Line of sight (LOS) is always important. The fewer obstacles between the Predictive Thermometer and the Display (or mobile device), the better. The same is true for when the Combustion Display is acting as a repeater: try to get the clearest possible LOS between the display and your mobile device. 

Kickstand position for the display is best. By keeping the display vertical, you maximize the functional length of the internal antenna. Especially when sitting on a stainless-steel counter (those can partially block the signal). 

Thermometer handle facing out: you can improve signal strength by keeping the thermometer on the side of the food closest to the oven door when practical. That way the signal doesn’t need to travel through the food (another bag of water).  

Escape hatch: in situations where direct LOS is not possible - like an enclosed smoker - the signal can get out through openings such as large-ish vent holes. A rule of thumb is, if light can get out (or in), the signal can too. (The exception being mesh screens on microwaves or trivection ovens - those are impervious). With the vents on your grill closed tight, the signal is just going to bounce around inside. 

Keep clear from metal: keep the handle of the thermometer to be as far away from metal as practical. The handle touching metal will reduce the signal. Ideally, try to keep the handle clear of any metal surface by an inch or two. Same goes for foil.  

Don’t stand between the antennas. It usually won’t make a difference but if you already have a compromised signal, keep your body out of the line of sight. Humans are mostly big bags of water, and water absorbs the energy from radio waves.

You call this science?

The engineers who built the Predictive Thermometer understand this stuff much better than I do. These answers are intended to be a kind of practical guide for non-engineers. There’s a lot more complexity than we can get into. Broad strokes, people.

OPEN SOURCE + DEVELOPER TOOLS

Will it work with smart appliances?

Yes! That’s the next step. We’ve made it as easy as possible for appliance makers to use the data broadcasted by the Predictive Thermometer. We chose open standards and open-source libraries for exactly that reason. Smart products are much smarter when they work together.  

You don’t have to be an official Combustion partner to use the data from our thermometer–it’s right out in the open for anyone who needs it. No software licensing or fees. No purchase agreement needed. If our cooking gear helps your cooking gear work better for our (mutual) customers, that’s good for everyone. 

(Psst: Exciting things are in the works with some large appliance makers. We’re not ready to spill the beans just yet. Soon!)

How can we become an official partner and integrate your thermometer into our appliances?

Start here: hello@combustion.inc. Obviously, there’s considerations and logistics that don’t belong in the FAQ, but we’d love to talk.

What about 3rd party apps?

Go nuts! The Predictive Thermometer transmits (“advertises”) all of its juicy thermometric data in the open, using an open standard (Combustion BLE Probe Spec).

We wanted it this way so smart appliances could use the data and other interested folks could make 3rd party apps. Everything a dev needs to get started is at Combustion’s GitHub. 

We love our app(s). But it’s impossible to build an app that’s all things to all people. The marquee feature of our app (and the display) is our proprietary algorithm that tells you exactly when your food will be done. That’s a super-important deduction! But it’s obviously not the only thing that data could be used for. 

Maybe you have a different idea about how temps could or should be logged. Or a better way to display them. Probably you’ll come up with uses we haven’t even thought of. We’d love that. 

The base app (and libraries) are open source, under the permissive MIT License. Our stuff is free to build on, and what you build remains yours. 

What’s the communication protocol?

The Predictive Thermometer sends data using an open standard: Combustion BLE Probe Spec (Bluetooth Low Energy). It will be up on our GitHub very soon (we’re still tweaking it).

ABOUT COMBUSTION INC.

Who are you people?

Combustion Inc is a team of people who love to cook. We spend our time designing, engineering, and manufacturing products that make cooking easier for everyone. We want to help you cook better. To be able to fearlessly master your favorite meals. We want to put juicy pork chops and and decadent beef wellington back on the menu. 

It all started with Chris Young. He’s our founder, an author (look up Modernist Cuisine: the Art and Science of Cooking), the co-founder of ChefSteps and the inventor of the Joule sous vide circulator. Before that he was the head development chef at Heston Blumenthal’s renowned Fat Duck restaurant. He’s been combining his love of science, technology, and cooking for nearly 20 years. Now he really wants a smarter thermometer in his kitchen. That’s what we’re building. For Chef Young, and for all of us.

OTHER QUESTIONS

Can I be a beta tester, influencer, or reviewer? Are you hiring?

Beta testing is already in the works. The other stuff is a possibility. Use this email: hello@combustion.inc to get started. For those of you who self-identify as a journalist, you can use press@combustion.inc if you'd prefer.

I’d like to sell these in my store. Please?

I know, right? For simplicity’s sake, we are currently selling only direct to consumers. But we’ll be looking to work with select retailers soon. Email us at retail@combustion.inc to get started.

I have a question that is not answered here!

Great! Or bad! We don’t know which. That definitely means it’s not quite as “frequently asked.” Please ask away on twitter: @IncCombustion.