Why You Need a Candy Thermometer

Meet your new best friend. Yes, a candy thermometer is your pal!   If you want to make candy you need this tool. Period.   It’s truly indispensable for all types of candy making from fudge to lollipops.

I know that some people are a little afraid of using a thermometer.   It sounds so scientific and you’re a cook, not a scientist. But candy making is kind of science-y.

Perfectly made caramels, toffee, taffy, hard crack candy all require sugar to be cooked to a certain temperature range or sugar stage. Sugar + heat = chemical reaction. In the case of lollipops, you’re taking a solid (sugar), mixing it with water and corn syrup to form a liquid, and then heating it until the sugar melts and becomes hard and transparent like GLASS! It’s sort of amazing if you think about it.


Candy thermometers (also called deep fry thermometers) are different from meat thermometers in that they can measure temperatures up to 400° F. A typical meat thermometer will only measure up to about 200° F.

metal candy thermometer lorann oilsdigital-thermometer

Candy thermometers come in various types from inexpensive glass to metal to digital.  Check out LorAnn’s selection of candy thermometers.  I prefer using a digital thermometer because it beeps when a set temperature is reached, but it doesn’t really matter which type you use or how much you spend as long as it measures temperature ACCURATELY. There is a simple test to determine if your candy thermometer is accurate. It’s called the Water Boil Test – and it’s EASY.

How to test the accuracy of a candy thermometer.

  1. Fill a saucepan halfway with water.  Attach candy thermometer to the side of the pan, making sure the tip doesn’t touch the bottom.
  2. Bring the water to a boil.
  3. When the water boils, check the temperature. Water boils at 212° F. (see note) which means your thermometer should read 212° F {100° C.}. If the reading is higher or lower, take the difference into account when testing the temperature of your sugar syrup – or get a new thermometer!

Note: At sea level, water boils at 212 °F. With each 500-feet increase in elevation, the boiling point of water is lowered by just under 1 °F.


So really there are only two things to remember when using a candy thermometer:

  1. Always check the thermometer’s accuracy before you beginning a cooking project.
  2. Make sure the tip does not touch the bottom of the pan.

That’s it!  Happy candy making!

For more candy making tips and tricks visit the Learn section of our website.




  1. How would I prolong the amount of time I have to hand form hard candy at home? I attempted to make a swirly pop and the candy crystallized, became unplayable, sooner than I wanted. I know that if i warm it back up before cooling completely I could prolong the amount of time I have to work with it. I just don’t know what temperature I need to warm it up to. I’m thinking of setting my oven to a certain temperature and putting the candy in the oven for a few minutes at a time. Could you please help me figure this out? Thank you in advance. 🙂

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