For a very long time, I have been wanting a decent cooking thermometer for checking doneness of food like meat or chicken. However I know all too well that good electronic thermometer generally very hard to find. The only one that I had considered buying is the one by Thermoworks. It is the first with excellent design as well as accuracy. The other very important characteristic is very low thermal mass. A lot of electronic thermometers have very large thermal mass. This is because thee use of cheap solid state sensor that is large. On top of that the metal casing itself is typically designed or simply large to make it cheap to produce. High thermal mass has a lot of problem. It can significantly skew the measurement due to heat conduction, especially if the sample being measured has low heat energy (e.g. a loaf of bread, or a cake). High thermal mass also requires very long time for the temperature to stabilized.
thermoworks' food thermapen thermometer - made in England
I wanted a Thermoworks thermometer but I just was not willing to pay $96 for one. I recently found this much cheaper brand on Amazon, and based on the review comments it is very close to the Thermoworks in performance. At less than 1/3 the cost. It is the Thermowand sold under Lavatools brand.
Judging from the larger diameter upper of the probe pin I expected it has slightly higher thermal mass than the Thermoworks. Comparing the specs shows it has slightly higher delay to reach measurement stability. However one has to take these specifications with a large grain of salt. It is dishwasher safe (top rack) but I would never throw it into a dishwasher. Why? I just know no consumer electronic product can withstand the rigor of dishwasher.
Today it arrived via Amazon's free snail shipping, and I could not without my eagerness to check it out.
for a sub-brand made in China it has a very nice and classy packaging
What is interesting is another test I did. I place the probe into a small glass of tab water. It took also a few seconds to stabilized to 66 F, as expected. As I removed the probe from the water I notice the temperature rapidly dropped. This is odd, I thought as the room temperature is about 73 F. I then realize what I am observing is evaporative cooling. The droplets of water on the probe tip cools the tip below the ambient temperature as they evaporates. Nice!
evaporative cooling due to water droplets on the probe tip
A few things that is worth pointing out on the much pricier and original Thermoworks' thermapen compared to the much cheaper copycat thermowand by Lavatools. The thermopen has a very generous 4.5" probe while the the one I bought has a much shorter 2.75" probe. The other is the measurement technology. Thermoworks' thermapen clearly state in the specification on it's website it is a type-k thermocouple. There is no such statement on the Lavatools' thermowand. I have to assume it is based on much cheaper and more common solid state sensor. If anything this is by far the most important difference. These are compromises I am happy to make for this $24.99 purchase, however. You get what you pay for.
To be fair to Thermoworks' $96 thermapen. It is really a very fair price for a thermometer based on type-K thermocouple. Typically thermocouple thermometer costs a few hundred dollars. If you are looking for the best food thermometer, I would recommend it without reservation.
thermapen is based on type-k thermocouple - hence the much higher price point
i made this surf and turf dish today - a sensible piece of NY steak and live clams
Update Dec 5, 2014:
I have very high hope with this Lavatools' thermowand thermometer. It is quite accurate when I just toy with it initially. Today I set out to check the accuracy more carefully. I planned to use ice water bath and boiling water. The ice water reading was 32.9 F. Close enough for me and it reading slightly high is expected because the probe will continue to rob the "cold". The next test is boiling water. As soon as I immersed the probe into the pot of boiling water the display blanks out. That is odd. I know it wasn't timing out in the auto off. I repeat this a number of time and each time the display blanked out after a few second, before the reading have time to stabilize. I have to fold it shut and unfold it to cycle-power. Nop, it is not usable. It is going back to Amazon. It either crash from the rapid rise of the reading, or the humidity from the steam cause the processor or electronics to fail.
I am going to order the real thing instead for a peace of mind - the $99 thermapen that is based on thermal couple. I just told myself I deserve it. I think I will get the lime green.
Until now I didn't realize how much bigger the thermapen is until I see the video below. It is so much bigger because of the much more complex and expensive measurement electronics for a commercial quality thermocouple instrument. It is traceable to NIST.
here is a video of how the thermapen is made in UK; you can see how involving the calibration process is - hence the much higher price
