FAQ

Wireless Thermometer Basics

How is it different than other wireless thermometers?

The Predictive Thermometer (CPT) has 8 sensors. Most wireless thermometers only have one or two.

“Extra” sensors let the CPT find the lowest internal temperature (TrueCore™) even if you missed the mark.

And they show you all the temperatures from the surface to the center (Total Temperature Awareness™).

So you know how evenly it’s cooking, how things are changing, and when exactly your food will be done to your exact specified temp.

You eat more than just the center of the food. So you need a thermometer that measures all the temperatures!

Wait, you leave it in the food the whole time?

Yes! That’s the biggest advantage of using ANY wireless thermometer. You can see the internal temp at any time while cooking, without sticking your head or hands or anything else in the oven (or grill or wherever).

This is also known as a “probe” or “leave-in” thermometer.

Because of our “extra” sensors, the Predictive Thermometer does a lot more than other probes.

It finds the lowest internal temp (TrueCore™), even if you poked past the center. You can't miss!

It tells you the real cooking temp at the surface (TrueSurface™). That shows you how much heat is actually getting into the food, so you can adjust your coals (or otherwise tweak the temp).

It’s all about getting more consistently delicious results, no matter what you cook.

Why should I care about the surface temperature?

The Predictive Thermometer is the only thermometer that can locate and measure the temp at the surface of your food (TrueSurface™).

That's the secret to consistent, precision cooking.

The temperature at the surface of your food is the best measure of heat being applied.

The surface is nowhere near as hot as the surrounding oven - 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 measuring surface temp, you can adjust your oven or smoker to 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.

Why do I need an ambient sensor? Isn’t that just the oven temp?

Nope. In fact, it’s not uncommon for the oven temp to be off by 100ºF or even 200ºF!

New Predictive Thermometer users are often appalled by this. We’ve gotten emails saying “this can’t be right!” But it is.

As it heats up, water inside your food evaporates into steam (212ºF). The steam tends to linger near the food, mixing with the hot oven air, and creating an invisible fog which - while still quite hot - is significantly cooler than the rest of the oven.

This is not actually bad news (it helps your food cook more evenly) but it is surprising to most people.

Because the Predictive Thermometer measures the ambient temp near your food, it captures the effect of this boundary layer.

If you want to see + hear more about this, Chris made a YouTube video that explains it really well. It also shows how convection (airflow) affects ambient temp. (Skip to 5:26 if you’re in a hurry to get back here.)

[Warning: video may make you hungry.]

Any other important differences?

•Our thermometer is a lot more slender than most other wireless probes. Easier stabbin’. Smaller holes.

•Wireless is designed to simply work, without the fussy “pairing” process.

•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 dedicated instant-read thermometers used in most professional kitchens.)

•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 is inserted "too far."

•Unlike other wireless 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 for pulled pork? Brisket? Etc?

Yes! The recommended temp limit for the lower 4 (tip) sensors is 212ºF (100ºC) but it can tolerate internal temps very safely up to that limit (and slightly beyond).

More about that below.

Can it be used in a rotisserie?

You bet your bird it can.

Can it go in the dishwasher?

Yes. The thermometer is highly water-resistant, rated IP68 (that's up to 1 meter for 30+ min!). We recommend hand-washing though, it just works better.

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.

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 for bread?

Yes! Bakers have reported fantastic results. It can also be used to check proofing temps or even profile your proof. Way to go, bakers!

Can it be used in a slow cooker (Crockpot)?

Yup. But keep the antenna (handle) above the water line. Liquid, especially protein and mineral-rich meat juices, is very effective at blocking radio waves.

Can it be used in a dutch oven?

It depends. It won’t harm the probe, but with the lid closed, you probably won’t get a signal out.

(Could you check-in by leaving the probe inside the roast or bread or whatever—and occasionally taking the lid off? Sure.)

Can it be used in a deep fryer?

Yes! As long as the thermometer is inserted into food up to its minimum insertion line. Don't use the tip to measure oil temp (fryer oil can exceed the lower sensors' max temp of 212ºF).

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 turkey fryer?

Yes, but be careful with that thing, you maniac.

Can it be used in a nuclear reactor?

Pictures or it didn’t happen.

Can it be used for candy-making?

Most candy requires temps above the max limit for the lower sensors. Check your recipe first!

What about cake?

Cake is great! You'll want the optional pot clip for use in cakes, brownies, cheesecakes and so on.

Specs and Tech

IP68 Waterproof Rating

It's official! The Predictive Thermometer now meets the IP68 standard.

6 = total protection against solid ingress (the highest rating)

8 = total protection against water ingress (up to and including complete submersion below one meter and for more than 30 minutes)

(March 2023)

600ºF Max Temp (315ºC)

Revised! Strenuous testing in the lab (and in the real world) revealed the heat tolerance is higher than originally estimated.

Upper sensor overheat alarms have also been reconfigured. Happy grilling!

(March 2024)

What if I want the internal temp near boiling? Pulled pork?!? Brisket?!?

Works great! No worries!

For slow-cooking, it’s not uncommon to hold meat at temperatures just below boiling – often around 205ºF. The Predictive Thermometer is designed for that and we’ve tested it extensively (we also love pulled pork!).

Allow me to explain:

•The electronics in the tip can tolerate temps a bit above the boiling point of water

•212ºF (100ºC) is a very easy-to-remember “safety line” to remember for most cooks (it’s not the hard limit, but it is a good rule-of-thumb)

Be sure the minimum insertion line is inside the food (i.e. not visible).

What is the max operating temperature?

600 °F (315 °C) above the minimum insertion line, including the ceramic handle.*

220°F / 105 °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.

*Revised March 2024

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.

What about the 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.]

How accurate are the sensors? Are they calibrated?

To quote one of our customers: “the accuracy far exceeds what’s required for cooking purposes.”

We use zero-calibration sensors that were originally designed for medical-class devices!

Our parts vendor guarantees their accuracy to be no worse than +/-0.2ºC (when between -10ºC and 65ºC) or +/- 0.3C (when over 65ºC).

In practice the performance is even better.

You don’t have to take our word for it - independent testers and reviewers (Amazing Ribs for instance) have verified our accuracy claims.

We also use a calibrated thermowell for inspection on our assembly line, just to be 100% sure.

P.S. The bigger issue with any thermometer is inaccurate placement. That’s why we put more sensors into the Predictive Thermometer, and spaced them out along the length of the thermometer.

Our 8-sensor array - combined with automatic TrueCore™ detection - makes it very hard to miss the spot. There’s always a sensor where you need one.

Is it totally waterproof?

Rated IP68, the Predictive Thermometer is waterproof up to and including "complete submersion below one meter and for more than 30 minutes."

The seal that keeps the water out also keeps out the cooking oil, drippings, marinade, and so on.

The Predictive Thermometer can go through the dishwasher (although hand-washing generally works better). You can spray it down in the sink, no problem, or run it under the tap.

NOTE: DO NOT “QUENCH” A HOT THERMOMETER

Wait for the thermometer to cool down before soaking or cleaning. If the handle is very hot, the shock of cold water can crack the ceramic.

(Side note: don’t touch the handle with bare hands or other body parts until it’s had time to cool off. It burns!)

The limits of the waterproofing really only show up under pressure. That’s why we don’t recommend using it (for instance) in pressure cookers.

Do I need the Display?

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.

Lastly, using the Display with the app greatly extends the functional range - up to 330ft (100m) in an ideal setup. The less ideal the setup (hello, BBQ), the more you'll appreciate that extra signal strength.

Why is it called a Range-extending Display? Is there a normal display?

The Display includes a range-extending feature. That's the only kind of display we sell.

The Display can work as the end point of your network - showing temps, controlling settings, etc.

OR it can be used as a repeater so that you can control + monitor the Predictive Thermometer using the Combustion Inc app.

With the Display + app, the potential range of the Bluetooth signal is doubled (you get an additional 330ft/100m of signal strength).

The practical value of that is you can place the Display near where you are cooking to scoop up a weakened signal (like one coming from inside a smoker) and boost it forward to wherever you are (hopefully not inside another metal box).

More about that below.

What’s the advantage of using the phone app?

A) There are lots of extras in the app, including pretty charts that track the temperature of your food anywhere along the thermometer (coming soon).

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. You can even give them nicknames and photos to ID them.

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.”

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.

All wireless products list “unobstructed range” so that’s what we tested – and that’s what we list on the site.

In a wide-open space with no obstructions and clear line-of-sight, our Bluetooth signals will travel 330ft (100m) or more.

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 consistently get at least 60-feet away (20m) with no issues.

The Range-Extending tools (Combustion Display or Booster) were designed to help out by listening to nearby thermometers and then repeating their signal.

So you add their range to the thermometer’s range, minus the radio obstacles, and there you have it.*

Best of all, these tools can also be used with each other to repeat the same signal for even more signal strength (read about MeatNet™ below).

Every Combustion tool works with every other Combustion tool.

TLDR: if you’re concerned about radio obstacles or range, add a Range-Extending Booster or Display.

All Combustion tools use the newest Bluetooth technology: BLE 5.4 (and are compatible with Coded PHY/Bluetooth Long Range, if and when a phone supports it).

BTW, the thermometer automatically logs all the data in its onboard memory (yes, there’s a tiny computer in there).

So even if you occasionally lose signal, you don’t ever lose track of where you are in the cook!

*More about wireless signals (more than you probably want to know) in the “All about Wireless” section just below.

How long does the battery last?

Battery life:

With a full charge, the Predictive Thermometer works for 28-30 hrs in cooking mode, or up to 24 hrs in instant-read mode (firmware v1.2.1 or higher).

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 up to 30 days on a full charge (with current hardware* + firmware v1.2.1 or higher).

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 10-20 minutes.

The Display battery charges in 80 minutes and is good for over a month of active use per charge.

The Display battery retains a charge for 6-8 months when not in use! (Note: in theory; no one's actually gone that long without using it.)

*Older versions of the thermometer have a 17-day standby limit. Still pretty good!

We often make minor hardware modifications for improved performance; in this case, 2022 thermometers had a very slow (and harmless) but annoying power leak.

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.

How do I charge the thermometer?

Use the included USB C-to-A cord and the included charger (or optional Booster). The Predictive Thermometer accepts charges from any standard USB port. So a phone charger or other power block is fine.

Many options are available to convert wall power to 5v USB power.

Don't use it with non-standard USB power supplies - these may be labeled "quick-charge" or something like that. That industry is very unregulated and you're depending on the engineering prowess and ethics of random individuals.

A non-standard charging port can create an excess of voltage and/or amperage that can overwhelm the charger. In that case, the charger will overheat and eventually destroy itself protecting the CPT.

We do not recommend testing that! It's dangerous and smells bad.

All About Wireless

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's MeatNet? How does range-boosting work?

Very well, thank you. Our goal was to make the technical side of this “magical” and invisible to the cook.

You don’t need to understand it to use it!

MeatNet™ is an ad-hoc mesh network.

That means it’s a network that forms itself and doesn’t require any intervention - you don’t have to have an access point… or router.

Every part of Combustion's MeatNet cooperates but they do not depend on each other to work.

Combustion devices (and the app) communicate directly with one another (peer-to-peer).

Importantly, breaking a connection does not interrupt an ongoing cook or reset anything.

This can be a huge problem for other wireless cooking products!

With MeatNet, if your phone (for instance) has to reboot mid-cook, no problem. Everything will pick up–live and in real time–when you get back.

More?

All data originates inside the Predictive Thermometer
The thermometer broadcasts this openly over Bluetooth
Some products (e.g. Combustion Display and Combustion Booster) include a “repeater” function
A repeater rebroadcasts the exact information it got from the Predictive Thermometer
Apps within range of any MeatNet device display the data

Ok, so?

So, a repeater (like the Combustion Display) lets you work around radio obstructions.

A lot of cooking is done in a metal enclosure. That greatly reduces radio range.

By putting a repeater nearby but outside of the enclosure, you get a fresh, full-strength signal that can be read from much farther away, even through walls or other obstructions.

All wireless products (including ours) list unobstructed range. But for practical cooking, you’re almost always going to be dealing with some obstructions.

What data does the Predictive Thermometer receive?

Target temperature instructions!
If a cook enters instructions (e.g. target temp) on the app or Display, the network passes those back to the thermometer (each Predictive Thermometer has a unique ID)
The thermometer then adjusts its setting and sends updated cooking data (including the new target) back out to be passed along
As they receive the new data, all MeatNet devices (and apps) will update to match. Synchronized!

Can you use a second repeater to extend the network even farther?

If you happen to have 2 MeatNet™ tools they can be used in sequence to extend the signal up to 1000ft (300m).

In theory you’ll be able to use up to 16 repeater-nodes daisy-chained together – for over a kilometer of effective range.

What’s the wireless range, really? How are you getting 1000ft?

In wide-open space with unobstructed line-of-sight Combustion’s Bluetooth signals will travel 330 feet (100m) or more. Per hop!

Each Combustion tool works as a repeater node in our proprietary self-organizing MeatNet™ mesh network.

Each time it repeats, that signal strength is renewed.

CPT alone= up to 330ft
1 hop = 660ft
2 hops = about 1000ft
3 hops = about 1350ft
And so on.

In theory, MeatNet supports up to 16 hops! That’s literally one mile of signal strength.

What’s the catch?

In real-world cooking, you’re almost always going to be dealing with some obstructions.

When the thermometer is locked inside a metal smoker, or if you live in a solid concrete building (and so forth), the signals don’t go as far.

This is a huge problem for our main competitor, and we worked very hard to avoid the same foibles.

Predictive Thermometer users routinely can get 60-feet away (20m) in real conditions with no drops, and that’s without a range-extender.

The Range-Extending tools (Booster, Display) were designed to help out by listening to nearby thermometers and then repeating their signal.

We’re the only wireless thermometer with this kind of mesh network and it makes a huge difference in actual cooking conditions. Especially smoking and grilling.

BTW, just to be safe, the Predictive Thermometer logs and stores all the data from a live cook.

If you wander out of range (or have solar flares or something) you get all the data as soon as you wander back.

No interruptions. No fussy re-connection.

It’s like you never left.

Why 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.

Using the Combustion Display and App together significantly boosts the functional range/signal strength. See the spec chart (above) for exact details.

What’s “Coded PHY”? Should I even care?

Not really; at least not yet.

Nobody has a phone that uses it yet.

Also known as “Bluetooth Long Range”, Coded PHY is a new Bluetooth protocol that promises greatly extended range.

It changes the RF signal at a physical level (hence “PHY”) and promises to change Bluetooth range limits from what they currently are (up to 330ft with our hardware) to a kilometer (about 10 times farther).

It’s also supposed to help with bandwidth congestion (Bluetooth uses the same bandwidth as other consumer wireless networks, including WiFi).

All Combustion tools are ready for this change when it comes - we already use BLE 5.4 and are compatible with Coded PHY.

Some competitors have made a big deal out of this.

It’s just hype at this point, but it is kinda nice to know that your gear is “future-proof.”

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 will greatly reduce the Predictive Thermometer’s effective range, especially if the water is in a metal pot.

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.

Food Safety

How do I know when my food is safe to eat?

The Combustion App automatically informs you when your food is safe to eat, applying the food-safety standards of the US government (USDA/FDA).

It’s a little bit complicated to explain (look here), but it’s extremely simple to use.

Just pick “simplified” or “integrated” (HINT: always choose integrated!), select your protein, when you’ll be eating it (right away or after cooling), and you’re good to go.

You’ll get a notification when your food passes the USDA recommendation for food safety.

Integrated standards track combined time-and-temps as your food heats up. Meeting these standards is just as effective as reaching a very high temp - either method kills 99.99999% of bacteria (that’s the USDA-safe level for chicken).

For example, 150ºF for 4.2 min is just as effective as cooking to 165ºF.

The USDA Food Safe feature is easy to use and the thermometer does all the math for you. With it, you never have to overcook anything “just to be sure.”

It will also alert you if your food spends too much time in the cool “danger zone” (40-135ºF) where bacteria thrive.

You don’t have to follow these recommendations if you don’t want to, but it sure is nice to know.

LEGAL NOTE: All home cooking is at your own risk. No warranty or guarantee of safety is implied. Please read the full terms (legal stuff!).

Why do you recommend using “Integrated” USDA safety standards?

Most foods will be well-done or even noticeably dry by the time they reach the hard internal temp threshold recommended by the simplified standard.

Particularly white-meat chicken or turkey breast!

Using the integrated standard, you’ll see that your food is safe long before that - so you can choose your doneness level with no worries.

Maybe the minimum safe level is not cooked enough for your taste (hey, it’s a matter of personal preference), but usually the lower peak temperature, the more tender and juicy the meat will be.

*There are exceptions. High-collagen foods like dark meat chicken or traditional BBQ meats (brisket, pork shoulder, etc) need to be cooked hotter and longer, well above even the simplified standard. Those foods get increasingly tender with extended time at a proper heat.

But my chicken is still pink!?

When you cook white meat to the “USDA Food Safe” recommended level, measured by the integrated standard, it’s very likely that the meat will remain pinkish. Don’t panic!

The pink is myoglobin that carries oxygen around in the muscle (it's not blood, which is hemoglobin).

Myoglobin starts to denature and lose its color around 140 °F, but this is a progressive change that doesn't happen all at once. Even at temperatures up to 170°F+ some myoglobin color can remain, particularly in the leg meat. This pinkness is usually darker near the bones.

We were all trained that pink chicken=danger. That’s just a rule of thumb and the thumb in this rule is very fat, outdated, and clumsy.

Pink chicken - cooked properly and safely - is tender and delicious.

It may take some getting used to!

I don’t need to cook my steak that much though, right?

It’s up to you! Always!

Food cooked at home does not need to meet the legal serving standard - it’s always considered “at your own risk.”

And these (USDA standards) are guidelines, intended to give you information, not limit your cooking!

The most popular way to cook steak is medium rare.

That probably won't meet the USDA Food Safe Integrated standard. It will NEVER meet the USDA Food Safe Simplified standard.

Steak is one of the safest foods to eat because it’s a whole muscle cut and beef is generally not at a high risk for exposure to salmonella.

You probably won’t get sick, even if you eat it raw (tartare). Your caveman lifestyle is not in danger.

What about slow cooking or sous vide?

Generally, with slow cooking or sous vide, you will far exceed the USDA recommendations for food safety.

Most slow-cooked foods (brisket, for example) require hotter temperatures plus a lot of time to break down the collagen.

They will exceed even the simplified standard. You’ll get a notification that it’s safe and then you’ll keep cooking for a while.

Part of the magic of sous vide is that it’s holding a steady temp for a long long time. If that temp is hot enough to kill bacteria (135ºF+) it’s extremely safe and effective.

Use the integrated standard for sous vide. Food cooked with sous vide will be USDA Food Safe long before it’s done.

Why do I have to set a target temp and a USDA parameter?

They're two different tools that work side-by-side.

The target temp is your "perfect doneness."

The USDA Food Safe badge means it’s been hot enough-for long enough-to be considered safe by the USDA/FDA.

We don’t tell you what the target temp should be because only you know how you like it.

Some people want it rare, some want it med-rare, medium, and so on. Different folks have different definitions of perfect doneness!

For example, Chris likes his chicken medium (a little pink) and his family likes it just over medium (barely pink).

The USDA Food Safe integrated feature adds up the temps at times to let you know IF your food is considered "safe" or not by the time it reaches your target.

Most times it will be. Sometimes, not (see: steak).

Do with that information what you will.

Home cooking is at your own risk. You're free to ignore the USDA Food Safe recommendation.

Some people have suggested it should work the other way around: that the USDA standard should dictate a target temp. That's how you end up with dry, overcooked chicken.

Not on our watch!

App Questions

How do I get the graphs to work?

Graphs will only appear when a thermometer is on and connected to the app.

If the graph is not visible, tap one of the temperatures. Voila!

To hide the graph, tap the settings icon (three vertical dots) and select "hide graph."

To show/hide the lines from any sensor, tap the color-coded circle below the temp.

Can I cook without the app?

Yes, if you have the Display. You will need the app to update the firmware on your Combustion tools, however. That's the software inside the tools themselves.

The Predictive Thermometer (CPT) is the only wireless thermometer that does all the calculations onboard - there's a tiny but powerful computer in there! That's a huge advantage because it means the CPT is not depending on an always-on connection to manage a cook.

Every other wireless set processes cooking data remotely, whether in-app or in the cloud. That's risky.

In the event of a disconnect - no matter how long or short - the Combustion Display and Combustion App pick up with up-to-the-second data and predictions because the thermometer itself is doing all the thinking.

What if I'm cooking "off-the-grid"?

No worries. You can still use the app to cook even without the internet.

Heck, you can use an old phone with no service (!) to monitor your Predictive Thermometer. As long as it has operational Bluetooth, you're good to go.

There's no sign-ins, no accounts, none of that nonsense. We don't put ads in the app or even recipes (though some people have complained about that).

The app is designed to be a control panel and display for the cook you are doing right now, telling you the information you need right now to make smart cooking decisions. It has one job and it does it to perfection.

You'll occasionally want to connect to the internet (use WiFi on that old Samsung) to get app updates and firmware updates for your Combustion tools. That's all the internet it needs.

Can I use a tablet instead?

Yes. Any mobile device running iOS or Android can use our app. You'll need Bluetooth enabled of course.

Apple Silicon Mac computers (M1 or M2) are also capable of running the Combustion Inc app. If you happen to have one.

Orders and Shipping

If I order today, how long will it take to get it?

In stock orders ship from our warehouse in 1-3 business days. Holiday shipping and handling takes longer: 3-5 business days.

US deliveries usually arrive 2-3 days later.

International orders vary a lot in time-to-deliver. 2-3 weeks is a fair guess, most of the time.

Backorders (ESD)

Because there’s a lot of demand for the product, and because we’re a small company, we don’t always have inventory on hand. When that's happening, there will be a small note on the product page and in checkout, showing the ESD (estimated ship date) -->"Ships: MM/DD/YYYY".

That's the date we expect to receive and begin processing the shipment for that order. There's a lot of variability in those dates, because of manufacturing, logistics, and freight.

Backorders can be canceled at any time before they leave our warehouse for a complete refund.

How much does shipping cost?

It depends.

US shipping is usually around $7-8.

International shipping is usually around $20, depending on your home country.

Since we’re doing the everything-included-at-check-out no-surprises thing, you’ll know before you buy.

TLDR: it’s calculated at the time of checkout.

Will it ship to my country?

Currently, we are 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.

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.

Open Source and Developer Tools

Will it work with smart appliances?

Yes! That’s the next step. We’ve made it as easy as possible for any appliance maker 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.

There's tons of info about that (and how to get started) on our developers page.

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. There's 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 on our developer's page.

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).

Start here: developers page.

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 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.

Country/region

FAQ