One of the most useful things you can have in your composting toolbox is a thermometer.
While you don’t need one if you have a small, cool heap, if you are hot composting it can allow you to assess the heat of your pile and let you know if you need to act to increase or decrease the temperature.
There are plenty of choices when it comes to these devices, but if you have a medium-sized pile, you’ll want to consider something like the Reotemp FG16P-C43 16-inch thermometer.
Why Reotemp?
There are plenty of compost thermometers on the market, but many sell cheaply made identikit thermometers that are rebranded for sale abroad.
That’s not to say they don’t work (I certainly haven’t tried all of them, even writing for a compost magazine!)
However, Reotemp is a well-known brand that is used by industrial composters. They have been making compost thermometers for decades, have a solid reputation and are members of the US Composting Council.
At a glance
The Reotemp 16 inch compost thermometer is a solidly made, hermetically sealed compost thermometer that displays temperatures from 32 -212 Fahrenheit to 0 to 100 Celsius.
The thermometer’s dial is divided into steady, active, and hot zones, allowing you to quickly gauge the health of your pile and determine if you need to take action to adjust the temperature.
The 16 inch stem is ideal for small to medium heaps, and larger options are available too.
It’s reasonably priced for a top brand, is solid and our tests showed it’s pretty accurate too.
Keep reading to find out more about the Reotemp Compost Thermometer, see our final review score and decide if it’s the right tool for you.
How I tested the device
One of the frustrating things about testing this device was waiting for the end of a cold winter!
Most of my composting takes place in the warmer months, with active composting limited to my HotBin – and, as we’ll see, this device is not ideal for a compost bin.
Still, the HotBin allowed me to start testing it in the colder winter months.
When spring finally arrived, I built a small compost heap and got it warm quickly (with the help of straw insulation) to allow further testing.
To test the accuracy, I used the ice water method. This entails:
- Filling a glass with ice.
- Adding water.
- Waiting for three minutes.
- Placing the thermometer in the glass.
- Monitoring the temperature, which should drop to 32°F/0°C.
What’s good…
Robust construction
Compost is not always dark and crumbly – a new compost heap can come with some heavier material.
So I like the robust construction of this device, which enables it to easily slide into heaps containing tougher material.
Made in the USA
American readers will be pleased to know that this is a US-made device, with the high standards of quality, craftsmanship, and durability you expect from a homegrown company with decades of experience in composting.
Color-coded dial
If you’ve been composting for a while, you’ll already have some idea of the temperature you are aiming for.
But even if you’re not a beginner, a color-coded dial makes it easy to take a reading when you are in a hurry.
(Being a compost nerd, I sometimes like to check the temperature before work!)
The Reotemp 16-inch thermometer is divided into steady, active and hot, allowing you to quickly gauge the health of your pile and know if you need to take action to adjust the
temperature.
Accuracy
As mentioned, I tested the device for accuracy with a glass of ice water. It did take about 2 minutes to get to the final temperature but then it settled about half a degree above zero.
Given the ice glass method is not going to be 100% accurate itself, I am quite happy with that result.
Price
Given the brand, construction and quality of this device, I think this thermometer is very well-priced and compares well against other, foreign-made devices.
Construction
While it’s not as solid as the Reotemp heavy-duty thermometer, this device is made from stainless steel and is solid enough for a home composter.
What’s not so good…
Takes a little while to display temperatures
Don’t expect to read your compost pile in seconds with this device.
You need to insert the thermometer into the device and wait for a few minutes for it to read the temperature.
When I did the ice test, I had to hold it for nearly two minutes to get the final reading.
Still, that’s quite common with non-digital compost thermometers.
I don’t mind waiting a little bit, but if you do want a fast reaction time, you might be better off with the FG20P Backyard Compost Thermometer, which has a 500 ms response time.
Inability to recalibrate
One thing this device does lack is the ability to recalibrate the device.
The only ones I know of that have this ability is the Reotemp professional range, and you do pay through the nose for that ability.
For my composting needs, I don’t require the thermometer to be accurate to the exact degree, so calibration is not super important.
(Especially given the price of thermometers that can be recalibrated!)
If you do need highly accurate readings for a major composting product, I’d recommend checking out the Reotemp heavy-duty 36-inch compost thermometer instead.
Is the digital guide a bit of an oversell?
The Reotemp promotes a digital guide on its listing.
I’m not sure what I was expecting, but be aware that all you get is a QR code on the packaging that you need to scan to access.
Is it any good?
I contacted Reotemp to explain that I had lost the box and requested a link, but I have not received a reply, so that’s one question I can’t answer!
Update: Reotemp did eventually get back to me. The digital guide is a simple (but clear and nicely put together) three page pdf guide to composting.
Other users report fogging
The Reotemp thermometer is hermetically sealed, which should mean moisture can not get in the device and fog it up.
I haven’t experienced any fogging, but while researching this post I did go through other reviews and found some reviewers reporting fogging.
This issue is not unusual with compost thermometers, and it can be easily resolved by leaving the device in a dry place for a while until the fogging disappears.
(Mine did fog on the outside, but, of course, that’s outside the control of the manufacturer.)
Update: It did fog in the end, although I was still able to read the dial.
Who is it for?
Currently, it’s measuring the temperature fine in my hot bin, but that’s only because I have a lot of fresh material in the bin.
Quite often I find that my smaller compost thermometer displays a higher temperature than the Reotemp device, as it’s located higher in a pile.
Unfortunately, Reotemp doesn’t have short stemmed options.
For a very large compost pile, the 16 inches is not likely to penetrate the core of the pile, so you might not know if the compost heap is getting too hot in the center.
I’d suggest looking at something larger, such as the Reotemp 24-inch or the heavy-duty 36-inch compost thermometer. (You will pay for the difference with the latter, though!)
For a small to medium size pile, though, it’s perfect.
Verdict
My biggest disappointment was not getting a response from Reotemp, which is not encouraging from a customer service perspective.
That keeps the final score from going above 4.
However, aside, for a sturdy, accurate and reasonable priced thermometer made in the United States, and for use in small-medium garden heaps, this thermometer is hard to beat!
If you think it’s the right device for you, click here to buy it now on Amazon US or Amazon UK. Remember, purchasing through our affiliate links helps support our work at no extra cost to you.
Still not sure which compost thermometer is right for you? Check out our other compost thermometer recommendations to find the perfect match for your composting needs.