Smarter grilling: thermometer with Bluetooth and WiFi

With thermometers you can take your skills to the next level on the grill. TechStage tries out cheap and expensive devices with WiFi and Bluetooth and explains what to watch out for.

The barbecue season beckons. If you want to venture into more complex grilled food than sausages, sooner or later you can't avoid a sensible thermometer. Especially with larger grilled items, expensive cuts or longer barbecuing sessions, this ensures that the core temperature of the item is not too high and at the same time you have the outside temperature under control. For this guide, we got several smart thermometers that send the temperatures to the smartphone via Bluetooth or WLAN. The idea: This way you can keep an eye on your grilled food without having to stand right next to it.

In this guide we show which points to watch out for, which techniques work better and why temperature monitoring is so important.

Low & Slow is the secret to great grilled meat. This not only benefits from pulled pork or leg of lamb, but above all from poultry. A whole chicken on a suitable holder develops a sensational taste, a crispy skin and is simply a pleasure after several hours around 90 to 120 degrees. In order for this method to work, however, the person (s) on the grill must know what is going on in the food. Only when the meat reaches a certain core temperature can you be sure that there are no more harmful bacteria in the meat.

Monitored BBQ: With thermometers, food can be cooked slowly and reliably at the right core temperature.

To reduce the number of bacteria, there are several values. For most home cooks, temperature and cooking time are probably the most relevant. Both can be balanced in such a way that you do not necessarily have to overcook grill pieces to make them unrecognizable so that they are safe. An important point is the source of the meat. If you can rely on the fact that your cooking pieces have a short path and that the cold chain has always been followed correctly, you can experiment a little more. If in doubt, you should therefore rather use grilled food from the butcher (who should ideally slaughter himself and thus keep the supply chains short). If you trust your source, you don't have to boil pork completely gray, for example, but can also serve it with a light pink shimmer.

The third volume “Animals & Plants” of the Modernist cuisine. But if you don't want to spend 400 euros for a cookbook collection, you can find the information in the cheaper one Modernist cuisine at home or should check with his local library if they have the books on loan. There is an extract with the relevant chapter at Scientific American in English.

There are several requirements for core temperatures, a good guide is that List of the website Kern They are often quoted and integrated into many devices Requirements of the American authority FDA. However, these are designed in such a way that they are the minimum indication of when meat, fish or seafood are guaranteed to be no longer harmful. According to the website, steaks, for example, should reach a core temperature of at least 63 degrees. This corresponds to a well-done steak that only appeals to a few people. This is where quality and origin come into play again. If you trust your butcher, you can easily prepare your Steak Rare (48 – 52 degrees Celsius) or Medium (55 to 59 degrees Celsius). Only in poultry should you play it safe because of the risk of salmonella and aim at a core temperature of around 80 degrees Celsius for whole chickens. A temperature of around 75 degrees is sufficient for the chest.

Depending on what the core temperature should be, the outside temperature of the grill can be 10 to 40 degrees higher. Usually you move between 90 degrees and 125 degrees. If you have reached the target temperature, you can briefly start up again to get the chicken skin really crispy. Whole chickens are one of the dishes that benefit enormously from the long time at low temperature. After several hours on the handle, the meat remains juicy and almost falls off by itself when you cut open the crispy skin.

In the test, we had three different thermometers with different concepts. The cheapest device is the Rosenstein & Sons NX5561, which is sold by Pearl among others. It is a grill thermometer with an attachable sensor, WLAN and a USB rechargeable battery. It costs around 22 euros at the time of the test. The second device also comes from Pearl and is the Rosenstein & Sons NX6305 professional grill thermometer. It offers up to six different connections for temperature probes, works with the app via Bluetooth and costs around 40 euros. Both devices are sold elsewhere under different names. The third device is the Meater (test report), a sensor with two temperature sensors and a Bluetooth connection to the app.

The thermometers in practice.

The affordable NX5561 already fails during setup. In the test with several smartphones, we were not able to integrate the device into our home WiFi. The associated app was so unstable that it completely froze when transferring the access data to the thermometer on several cell phones and the data simply did not want to get to the thermometer. So here's a warning in advance: You should be careful with cheap thermometers and WiFi apps that a third-party provider builds for all models.

The NX5561 comes with its own battery, which is charged via Bluetooth.

We drove significantly better with the Bluetooth models from Rosenstein & Söhne and the Meater. The coupling in the apps was done quickly, even if the thermometer from Rosenstein & Söhne did not initially ask for access to the location data in the app. This means that you first have to switch to the rights of the Android app yourself and share the location there – otherwise the app cannot use the Bluetooth function. An annoying mistake. The Meater app, which found the sensor without problems, shows how it can be done better.

The NX6305 transmits information from up to six temperature probes to the app via Bluetooth.

This shows a big problem with these inexpensive devices: Most come from the same manufacturer and are given a different name and housing for the respective seller. Nobody cares about the apps, because you can rely on the developers to do a good job. In most cases this is true, but often things go wrong.

The Meater, on the other hand, was easy to set up. The functions Meater Link and Meater Cloud are available for greater range. The former allows a smartphone to communicate the status of the temperature to other devices. In other words, if you place an old cell phone next to the grill, you can query the data from another smartphone. This can also be done on the go via the Internet via the Meater Cloud. The function is also integrated in the Meater Block, which, in addition to four Meater thermometers, comes with a WLAN module for communication. But then you put down almost 300 euros.

The Meater has two temperature probes and works completely without cables.

All devices perform well in terms of accuracy. The cheapest WiFi thermometer is a bit faster than the Bluetooth counterpart, but this can also be due to the placement. There should no longer be any major deviations here.

If the finished devices are not enough, you can build your own thermometer using a Raspberrry Pi or an Arduino. The advantage of these devices is not only that you are incredibly flexible and do not have to worry about data protection. Since the small computers have more computing power than most finished thermometers, they can also be used to regulate the temperature.

Probably one of the most mature and extensive projects in this area WiFi thermo. The thermometer is available in different versions and with accessories such as a fan or a Pitmaster control. It is a German-language project, so questions can be asked in the active German forum and solutions can be found. The project is definitely worth a look, especially for hobbyists who want to read more than just temperature. If you can do without the control, you get a ready-made WLAN Thermo Nano Lite (without Pitmaster control) for 126 euros, if you build it yourself and print the housing yourself (3D printer guide), you pay less than 100 euros.

An alternative is HeaterMeter. Instead of a simple thermometer you get a “BBQ platform” to which several temperature sensors can be connected. The project has an extensive wiki and a forum for questions or craft ideas.

If you want to take your skills on the grill and stove to the next level, you can't avoid a thermometer. Inexpensive penetration thermometers are a good first start. If you want to monitor grilled food for longer, you should use devices with at least two temperature probes. Because in addition to the core temperature, the ambient temperature is just as important. We would not recommend cheap devices with WiFi, they were just too bitchy in the test.

Finished: The skin is crispy but not burnt, the flesh inside is juicy and falls off the bone. Everything with minimal effort, only time is needed.

Bluetooth is better, but the range limit often strikes here. Meater solves this very cleverly with the Meater Link, everyone probably has an old cell phone lying around somewhere. Another advantage of the theater was mentioned in the comments to the original test: it can be used with rotisseries without any problems because there is no cable that could get tangled.

Specifically, we would make the following recommendation: If you want to spend less than 40 euros, you should go for a reasonable brand device, such as Rößle or Weber, someone who can be addressed with a problematic app. If you have more money in hand, you can use the Rosenstein & Söhne professional grill thermometer or the Meater.

If you want to use WLAN and are willing to invest something in reasonable equipment, we recommend the WLAN Thermo. The devices are not only repairable, but can also be expanded or equipped with new thermometers thanks to different connections. There is also a reasonable web interface that does not rely on cheap third-party apps.