Every baker needs a reliable sugar thermometer. Some things just can't be made without one (tempered chocolate). And other things will always be better if they are made with a thermometer on hand (sponge cakes, we're looking at you). 

With a multitude of options on the market, from cheap-as-chips traditional jam thermometers to premium instant-read thermometers, we decided to break down how to buy the best sugar thermometer for you. Read on to find out what to look for when buying a sugar thermometer and which ones we recommend. 

Sugar thermometer FAQs

What is a sugar thermometer used for?

Sugar thermometers are an essential tool in a baker's arsenal. Using precise temperature measurements for everything from baking a cake to caramelizing sugar ensures consistently perfect results. Check out our Temperature Guide to find all of the baking and confectionery temperatures you need.

Choosing a traditional sugar thermometer limits your device to liquids such as condiments, sauces and frying oil, whereas a digital sugar or kitchen thermometer can be used for anything from roast chicken and steaks to bread and chocolate. Learn more about the difference between traditional and digital sugar thermometers below.

How to use a jam thermometer?

When using a digital sugar thermometer to test the temperature of a liquid, such as melted chocolate, jam or sugar syrup, place the probe into the liquid and stir. The temperature won't be exactly the same throughout, so move the probe around to get a better reading. Make sure you don't touch the bottom of the pan though, as this will give you an inaccurate temperature. Make sure to check the temperature often too as it can move very quickly and become overdone in an instant. Choosing a fast-reading thermometer like our Thermapen One is helpful here because it doesn't waste time stabilising.

To read the internal temperature of solid food like cakes and bread, insert the probe into the thickest part.

As you move the probe slowly through the food, you'll see the temperature reduce towards the centre; this helps you to find the middle and the coolest point. You might also like to probe a few other places too, just to make sure it's come to temperature throughout.

Can you use a meat thermometer for sugar?

Absolutely. Instant-read meat thermometers are perfect for measuring the temperature of any solid, semi-solid or liquid food. In fact, they're a better choice than a traditional sugar thermometer because they're more accurate, fast and versatile.

What to look for when buying a sugar thermometer

Accuracy

Baking temperatures are all about precision. Jam will perfectly set at 105 °C, not a degree above or below.

Choose a thermometer with a high accuracy of ±0.5 °C or less. Some thermometers come with a calibration certificate, so you can be sure it has been calibrated to a high standard.

Speed

It can feel like you're waiting a long time for the temperature of your jam or caramel to rise initially. Then the next thing you know, it's rising rapidly, and you're worried it's going to burn.

Your cooks can become overdone in an instant. So waiting for your thermometer to catch up with the increase really defeats the point of working to temperature.

Some sugar thermometers can take up to 20 seconds to stabilise. For the best bakes, you really want to choose a thermometer with fast readings of three seconds or less.

Ease of use

As we've already mentioned, speed and accuracy are really of the essence when you're making confectionery. So struggling to read your thermometer can also hinder your process.

Make sure the temperature on your baking thermometer is clear to read, digital thermometers are best for this.

Confectionery can also be pretty messy and sticky, so it's great to have one that's easy to clean.

Traditional sugar thermometers

Traditional sugar thermometers contain a glass tube which is filled with alcohol or mercury. The line will move up the thermometer as it heats, and it will often be marked with essential temperatures such as jam, frying oil and caramel. They often clip onto the side of your pan to continuously monitor the temperature.

Traditional sugar thermometers are cheap and simple to use. However, there are a few disadvantages to choosing one of these over a digital kitchen thermometer.

Slow and inaccurate readings

They are slow to come to temperature, often taking upwards of 20 seconds to get an accurate reading. They are also far less accurate than digital thermometers, and the measurements can drift out of calibration easily.

Difficult to read

Traditional sugar thermometers feature tiny measurement scales, which can be tricky to read, especially when placed in a steaming pot of jam.

Unreliable and Unhygienic

The glass can actually break, making your thermometer useless and ruining your confectionery in the process.

In addition, the thermometer's ridges can cause seed crystal formation and make it more difficult to clean.

Digital sugar thermometers

Digital jam thermometers or instant-read kitchen thermometers are a great choice for bakers. They're an essential tool for any cooking lover because they can be used on anything, from Sunday roasts and summer BBQs to date night steaks and Mother's Day cakes.

Versatile

Can be used for any type of cooking.

Reliable

Fast and accurate temperatures. More robust design.

Easy to use

Readings are clearly displayed.

Learn more about our favourites and find the best sugar thermometer for you.

Thermapen ONE Thermometer

The Thermapen ONE is the ultimate thermometer for sugar, featuring an unrivalled speed and accuracy.

Reading temperatures in just one second, you know exactly when your food is ready to come off the heat. The Thermapen ONE has a high accuracy of ±0.3 °C (between -19.9 and 119.9 °C). They're also calibrated by hand at our factories in West Sussex, and supplied with a free calibration certificate to show this.

The Thermapen ONE has a number of features for easy use and reading. It automatically switches on and off when picked up or set down, so you don't have to wait for it to fire up or fiddle around with buttons.

 It also has a 360° auto-rotating screen, which makes it easy to read no matter which angle you read it from or which hand you hold it in. In addition, the backlight will automatically switch on in low lighting, making the temperature clear in all settings.

Designed for easy cleaning, the Thermapen ONE is waterproof which is perfect for thoroughly cleaning off sticky treats. The casing also includes Biomaster antimicrobial technology to reduce bacterial growth.

Thermapen Classic Thermometer

The Thermapen Classic is the essential kitchen thermometer with fast and accurate temperature measurements for sugar.

It may not have the bells and whistles of the Thermapen One, but its sleek and high-quality design still cuts above budget sugar thermometers on the market. 

The Thermapen Classic features a high accuracy of ±0.4 °C and reads temperatures in just three seconds. It also comes with a free calibration certificate so you can be confident in the accuracy of your readings.

The casing is water resistant, so you can wipe it clean easily, and it features Biomaster antimicrobial technology to reduce bacterial growth. 

Simply unfold the probe to start quickly measuring your sugar temperatures. 

ThermaStick Pocket Thermometer

The ThermaStick is the best budget thermometer for sugar and baking. 

It doesn't feature the handy folding probe that the Thermapen thermometers have, and its digital display is slightly smaller, but it still performs where it matters most: quality and accuracy.

The ThermaStick is accurate to ±0.5 °C, and it's waterproof and easy to clean. Perfect for beginner bakers who aren't ready to invest in the expensive kit yet.