Candy Thermometers

candy thermometer

A friend once told me that the one word which terrifies people, enough to dissuade them from tackling a recipe, was the word “thermometer.” Candy making generally requires the use of a thermometer and I’m not sure why people get uneasy around thermometers because like kitchen scales, when things are in precise measurements – like degrees, pounds, or grams – it’s pretty straightforward. In fact, when you think about it, grilling meat or fish to the right point require far more savvy than simply reading the numbers on a thermometer.

Candy (also know as deep-fry thermometers) are readily available in houseware stores and almost every supermarket in the states. So there’s no reason to be wary of them as some baking, and candy making projects really do require the use of one. But sometimes recipes don’t turn out as intended and although candy making is famously persnickety (factors such as temperature of ingredients, weather, and variations in ingredients, like various chocolates, butters, and sugars can affect the results) many candy making issues can be resolved by verifying the accuracy of your thermometer.

To do this, simply clip the thermometer to the side of the pan, making sure the bulb isn’t in contact with the bottom, then add water and bring the water to a full boil. Do not plunge a thermometer into boiling water since the extreme temperature shock can cause it to break.

At sea level, the thermometer should read 212ºF, or 100ºC. If it doesn’t, it’s time to get a new thermometer.


If using one of those probe-type digital thermometers, make sure the tip of the probe isn’t touching the bottom of the pan if testing it, or if using it for candy making. I blew my first one out because the tip of the probe was touching the bottom of the pot while I was boiling a sugar syrup, which ruined the thermometer.

A few thermometer tips:

-Store glass bulb-type in a sturdy paper towel tube, so they don’t break. (Some say to store thermometers upright, but in my kitchen, that presents a storage problem. I do test my thermometers regularly and never found that storing them flat had any adverse effects.)

-It’s best to hand wash thermometers since dishwashers can knock them around and throw them out of whack. And strong detergents can also wear down the numbers, too.

-Keep a spare thermometer on hand. Since thermometers can break (especially annoying when you’re in the middle of a project), it’s nice to have a back-up thermometer waiting in the wings.

-I’ve used metal and glass thermometers and really haven’t found much of a difference. This Taylor is quite good and what I prefer, although the glass ones (as shown in the post, poking out of the tubes) work fine. They are more prone to breakage before of the exposed glass so take extra care when using them. Digital thermometers have their fans, although I’ve haven’t taken to them as much as other people have.

Related Posts and Links

Altitude-Based Water Boiling Point Calculator

Chocolate-Almond Buttercrunch Toffee Recipe

Homemade Marshmallow Recipe

Salted Butter Caramel Recipe

CDN Thermometers (Company Website)

Taylor Thermometers (Company Website)

Baking Tips Archives


  • A couple of days ago, I finally used my neglected candy thermometer…to make fudge. It’s an old metal one. I’ve didn’t verify the accuracy, but the candy turned out well. But, do metal thermometers have to be clipped to the side of the pan? I just set mine in there, and it was probably touching the bottom…

  • hi meredith: I didn’t ever think about the bottom of the pan being all that much hotter than the contents of the pan; I just naturally clipped the thermometer to the side, since it held it in place and was less-prone to breakage. It wasn’t until I blew out the probe of the digital one and I called them, and they told me that that was why it happened.

    Although I thought I had a pretty good case, they refused to send me a replacement. However I did notice in future notices with those digital thermometers (which I read when I was teaching in cookware stores) they now say to make sure the probe isn’t touching the bottom. I like to think it was me on the phone with them for thirty minutes which made them add that to subsequent instruction booklets ; )

  • I’ve often wondered what people do about sugar depths when making candy. My thermometers always have a depth that the sugar should be for an accurate read, but it seems my sugar is never deep enough. I always use the suggested pan size, too. Is this a common problem? Is there a type of thermometer that has shallower reading depths? I usually end up tilting my pan to over the testing depth for the thermometer, which I know isn’t efficient.

  • emily: It’s tough because if you use a narrower pan, it’s harder to balance on a gas burner (it’s not as stable as a wider pan) so generally speaking, you do need to tilt the syrup to submerge the bulb in some instances in order to get an accurate reading.

    But if it makes you feel any better, we did that when I was in professional pastry classes here in France at Lenôtre and Valrhona when making candy – so you’re not alone!

  • Candy thermometers used to scare the bejesus out of me, but then I faced my fears and bought one. It absolutely changed my life. I couldn’t make caramels or brittle without the little guy!

  • Yes, I have a candy thermometer. Why? I don’t know. Still buying candy… maybe will experiment when it is not necessary that I have a finished product.

  • How funny, I just bought a Taylor candy thermometer (the only kind the store had) yesterday to make your chocolate-almond buttercrunch toffee. It turned out great! I will pack it up for gifts today. Thanks a lot!

  • This couldn’t be timelier, as I’m attempting a batch of horehound candy today as a recipe tester, and have never used one of these before. Naturally, I’ve been intimidated, but now I feel much better!

  • Up until yesterday – when I made your marshmallow recipe for the first time – thermometers scared me too. I think it’s because they require you to be very accurate, no room for error, which of course is why recipes I’ve tried in the past while ignoring the recommended thermometer have quite often failed. So yay for thermometers…and homemade marshmallows! I’ll never go back.

  • Sadly, from first hand experience, I agree with the always have one extra around! You never know what will happen, usually when you need it or are in the midst of using it!

  • David, I like the digital thermometers because they are so much easier to clean than the glass ones. Especially now that I’m older and forced to wear reading glasses for any type of up-close activities.

  • Thank you for this post. I just purchased a solid copper pot and with my candy thermometer everything I am making is turning out fantastic! I use the Taylor one too. Thank you again for all your interesting tips and recipes. I feel like I am at a culinary school when I read your articles.

  • How timely! I’m going to make your marshmallow recipe today. Thanks for the tip.

  • Funny that you would post this today. I just had a major candy making disaster yesterday! I will have to say that my grandmother’s fudge recipe is notoriously difficult to get right and also has really vague instructions like “cool until you can hold your hand to the bottom of the pot.” I think that sort of instruction varies for each person!

    However I persevere and will try again today. I checked my thermometer last year but didn’t before I used it this time. Maybe I will try that before I waste another 3 cups of sugar.

  • Like Crissy, candy thermometers simply terrified me – and I have been cooking since I was five. My mother never used one and she was the candy maker par excellence with everything always turning out perfectly. Somehow I have never seemed to have the touch so I have avoided some recipes that I found very attractive. The point presently being that this post has given me new courage and the kitchen supply store will shortly be selling me a couple of thermometers. Thanks for the infused courage.

  • Thanks for this David… I needed a good thermometer recommendation. I’d like to try making marshmallows this season and will probably be in use of one. Also, thermometers would be needed for heating up milk for raw milk yogurt making.

  • Are candy and jam thermometers the same thing? Other than the fact that the jam ones list when one reaches setting point for jam and the candy ones list soft and hard points for boiling candy?
    What I mean is, if one knows the temperatures one needs, is there any reason not to use them interchangeably?
    Or do they go up to different highest temps?

  • I am definitely one of those people who cower at the word “thermometer”. The only method I’ve ever used is dipping a spoon into the stove top mixture then placing my spoon in a glass of chilled water and seeing how hard/soft it ends up. How much further from accuracy can I get, right? Ah well, it’s worked thus far for toffee and should I branch out, I will use these tips to help walk me through my fears.

  • I feel like if you cook a decent amount you should just bite the bullet and buy a Thermapen. Yeah, it costs like a hundred bucks, but you can use it to make anything from yogurt to caramel to prime rib. Our candy thermometer, which we should obviously just throw away, is off by like 30 degrees.

  • Good info! I use the Taylor’s thermometer and so far it’s worked for me. Your so right though about so many other factors that can throw off the end result of the candy no matter what temp you pull it at.
    Take care..

  • I use a digital thermometer as it easier for me. A traditional one installs a fear of my daughter breaking it, and having to clean up mercury.

    • That’s definitely a concern regarding glass thermometers. I’ve only broken one once. But I’m very careful when using one.

  • Thanks for the tip on testing thermometers. It makes perfect sense to do that but never occurred to me. I have two of the glass kind and they have worked just fine – so far.

  • I love my Taylor candy thermometer. Its a necessity for when I make marshmallows. And other things, but mainly marshmallows.

  • Great post. Thanks!

  • Great post David, and very timely! I admit I simply haven’t made many things that require a candy thermometer, possibly because of that or maybe just because I don’t have a big sweet tooth. But this time of year everyone’s in the mood for candy, so I may just go buy one!

  • You little sugar-bugger, you answered my concern via Emily’s question.

    We are not alone…..tis nice to know. I thought I was riding the short bus on this one. Someone should invent us a thermometer that yells, “Oh No! I’m touching the bottom of the pan!”

  • Wow-you can actually read the words “firm ball, soft ball, hard crack” on your thermometer. Mine is so old I just see faint impressions of where those words once were (and yes, I do hand wash it). I guess it’s time to ask the elves for a new candy thermometer…

  • Candy thermometers don’t intimidate me at all, the rare times I do make candy. Now..meat thermometers…there is a problem. The ones I buy never seem to be accurate. Used per directions, the two I have (one is instant read, the other a Polder digital) will give two different readings. Have to judge doneness by smell and texture and hope for the best when the slicing commences. Any advice re: accurate brand to purchase?

    • The two brands that I mentioned in the “related links” at the end of the post are brands that I’ve found reliably good.

  • I’ve been using a candy thermometerfor making jam and caramel for years. I don’t understand why anyone would be afraid of them. I’m afraid of not using one. After speaking to a barista about the right temperature to heat milk to for coffee, I now use it to get my milk the right temp. For those interested it is between 67 a 70 degrees celcius.

  • I have the candy thermometer fear so thanks for this post. It helps me get over my hang-up. I have a new thermometer sitting in the package, still waiting to be used. Apparently I was delusional about what kind of time I had to actually do something with it. I’m still hoping to give it a go soon.

  • I like a digital thermometer with a probe (esp. Thermapen) for use in taking the temperature of meat. They give you a temperature really fast. I haven’t done a lot of candy making yet, but when I do I’ll invest in the one you recommended here.

  • To keep it off the bottom, I’ve tried ever so hard to balance the tip of my candy thermometer on a wooden spoon half-submerged in the lava, I mean boiling sugar solution. Sometimes it works …

  • I cannot prepare candy without a thermometer and I love my glass one. Great trick storing in a paper towel tube!

  • I still can’t figure out the pan thing. I have a small and medium AllClad. One narrows ant the base. I can’t seem to clip the thermometer to the side. Any thoughts on pan type and size? Thanks

  • I wonder about your thoughts on infrared thermometers David? I find I primarily use mine with my digital probe secondarily. It is required when tempering chocolate using the slab method although I think you prefer seeding? Although I find the candy thermometer is easier while bringing sugar up to hard or soft ball for whatever as I can just sit there and watch the indicator rise.

    • I have one that I bought when I was learning to temper chocolate many years ago in school and they work fine for using the slab method – but since they only measure surface temperature, and not below the surface, I find infrared thermometers of limited use

  • I’m afraid of all thermometers, except the kind outside your kitchen window…

  • Great information David! I’ll be sure the next time I post a recipe for candy and mention a candy thermometer to link to this post.

  • I too had been leery of my glass thermometer- the only one I had and never saw the need to invest in a new one ’cause I never used it… and it always broke in my utensil drawer.

    I used to make fudge growing up and would throw a spoonful of the candy into a glass of ice water to see what stage it was at- it was quite nice as I would get a small treat to taste as I was cooking.

    I recently tried the digital one (on clearance at some cooking store) motivated by making your Salted butter caramels (which are just mouth wateringly divine) and found that the mere one or two degrees it was off by would alter the precise consistency I was looking for- I do them to 250F. The problem now is that it only takes me 20″ to whip up a batch- very dangerous!

    So, I went all out and spent the 14 bucks on the Taylor, and I am hooked. It keeps the bulb off the bottom of the pot, it clips nicely to the side, and it’s accurate! I just soak it in the pot I used and it washes off without much effort.

    @ Kathleen Clarke: I found my newest and most favorite pot for pudding, custard, caramel, etc is a 3qt all-clad saucier- the round bottom just makes so much sense. I am pretty sure I got that idea from David- your post on the caramels maybe?

  • Not sure why people are scared of using a thermometer – I’m scared of not using one! So much easier than trying to figure out if something is at the right stage by myself. Got the tip about storing it inside a paper towel inner from Ready For Dessert – sheer brilliance!

  • I wish I could rely on thermometers but I live at altitude and don’t have the math in my head. So, I have learned to determine the set point of jam by how it coats a spoon (the freezer method never worked for me) or how it appears in the pan. Unless candy is really obvious, I don’t even bother. Again, that thermometer issue. I think my reading should be 10 degrees less than stated but am not sure.

  • Great information – thank you! I use a thermometer and – once you get used to it – it’s quite handy to have in the kitchen!

  • I prefer the metal Taylor thermometer also. There is a bar at the bottom of the thermometer that guarantees that the bulb will not touch the bottom of the pan. Everytime I whip out my handy thermometer, I always wonder how people managed to make candy without thermometers or corn syrup or marshmallow cream. They certainly have my admiration.

  • I made a recipe that called for tempering chocolate the other day and relied heavily on my thermometer. In the end the chocolate still bloomed when set. Is it possible the temperature of the kitchen affected the tempering? We keep our thermostat turned way down. I have tested my thermometer so I know it is accurate.


    • Some chocolates temper at different temperatures and often packages (or websites) say what temperatures one should take it to. Ambient temperature can affect tempering as well. However even professionals make mistakes and I was at a chocolate candy factory in California and they were unwrapping cases and cases of chocolate bars that were intended for delivery to a store, because they had all bloomed.

  • Hi David–I have a candy thermometer, like the one pictured, but it’s no help for tempering chocolate because the temperatures don’t go low enough. Do you have another thermometer that you use for chocolate? Thanks!

  • Mercury gets a bad rap these days (it is deadly poison I suppose), but you won’t die just from touching it. My brother and I used to play with mercury for hours when we were kids (it’s fascinating stuff). I’m not saying that you should eat candy with mercury in it from a broken thermometer (you definitely should not), but there’s also no reason to go all “nanny state” and avoid using glass thermometers for fear of mercury…

  • I love my candy thermometers (yes, I have 2) and I could not confidently make my now-famous buttercrunch toffee (aka Krack) without it. I’ve never been good at the cold water test for correct sugar phases, so the thermometer is my favorite tool in the kitchen.

    How about some more tips on successful candymaking?

  • Thanks, I guess that means I need to research the specific brand of chocolate I was using. I may also turn the thermostat up next time I try to temper chocolate. They may have been ugly but the cookies I made were still amazing. I was kind of hoping they wouldn’t be, because they were not just a scoop and bake treat.


  • I don’t avoid making candy because of having to use a thermometer, but because we live at altitude (7000 feet), so the temperatures given in recipes don’t work for us. I know I should have paid more attention in physics class, but I think it is because the boiling point at altitude is lower than at sea level. I made your marmalade recipe this weekend, and no matter how long I cooked the mixture, it would not rise to the 220 degrees specified in the recipe. Someday, I will do the research to figure this all out!

  • Julia and Denise, I have a friend who lives at high altitude close to Denver and likes to make jam. He says to subtract 2 degrees from the stated temperature for every 1000 feet you live above sea level. So Denise you would subtract 14 degrees from the stated temperature of your recipe or if you live 7500 ft above sea level, then subtract 15 degrees. Hope this makes sense. Here is a link to help.

  • I hope it’s not too confrontational to leave a couple of corrections/helps in the comments here!

    Thermometers don’t need to be thrown away if they don’t read 212 F at boiling temp. In some cases, especially if you live at elevation, it will read a little bit lower or higher when the water is boiling.

    Just calibrate it, that is, make a note of how many degrees off your thermometer is from the “correct” temp and recall that when making candies. It works out similarly to the rule left by another commenter, but ALSO takes into account any thermometer inaccuracy (from the factory, or transport, or age.) For example:

    My thermometer reads 200F for boiling water, which is 12 degrees below the correct temp. When I make divinity, which should be cooked to 250F at sea level, I take my syrup off the heat when my thermometer reads 238F (12 degrees below the target temp.)

  • Ha! I just bought one, because I felt like I was missing out on the thermometer-mentioning recipes. Have not tried it yet , though.

  • I read the reviews of the Taylor thermometer at Amazon. Many complained that the numbers came off, even melted into their candy. Has Taylor fixed that or is it still a problem?

    • The one in the post is the one I use and the numbers are still in pretty good shape. I’ve had it for a few years (5+) but do handwash it. I haven’t noticed the syrup taking its toll on them on mine either.

      (You do sometimes need to read reviews carefully since I saw a bad review of a carbon steel santuko knife that I have, which is really great, and some “chef” gave it a very poor review because he complained that it stained, and the blade got ruined because when he didn’t dry it off after washing and using it – which happens to carbon steel knives if you don’t care for them properly.)

  • good to know! handy for candy season :)

  • Dear David,
    I am sorry did not write sooner to compliment you on the beautiful Paris morning excursion.I enjoyed it,want more..
    Best and Kind regards,
    Sandra Castro

  • Talk about a neglected candy thermometer, I bought my wife a really nice candy thermometer about two years ago because she just had to have one. There it sits in the original packaging. She hasn’t even opened it yet.

  • The glass/mercury sugar thermometer I use fogs up in no time flat. Water vapour condenses in the glass cylinder and makes it totally illegible. I live at sea level, and humidity is high (Sydney, Australia), but it seems that should not have such a potent impact. Any solutions?

  • I need a thermometer to take the guesswork out of yogurt making. I guess this would be the same thing?

  • I’ve never figured out how to correctly use a meat thermometer. Instructions say not to place on the bone but i always wonder if it is placed in a spot where I am getting an accurate read.

  • A few Septembers ago I found a beautiful Mauviel Copper pot at a Vide grenier in the Paris suburb of ST Mande. What luck since I paid about $20.00 for it. It is the perfect size for candy making and holds my glass thermometer at about 1.5 inches above the bottom. I now find myself not shying away from a recipe that says candy thermometer! Having the right tools make all the difference.
    Joyeux Noel to you all.

  • David, just saw your ecookbooks on site, after reading about it in the NYTimes. Epicurious also saves the whole cookbook to your recipe box on their site. Very exciting…now if only Santa will bring me an iPad for Christmas :)

  • I have tried a few of these Taylor thermometers, and for whatever reason, they always seemed to take forever to register the right temperature. I use a cheap glass thermometer that works a lot quicker. Strange eh?

  • I bought a candy thermometer a while back but never got around to use it. After reading your tips, I might adventure myself and make some candy after the holidays. Thanks for sharing.
    Happy Holidays David!

  • I am at the other end of the country. I am a chef who left the UK to live and work in the South of France 3 years ago. This Christmas I wanted to buy a cooking thermometer to make samosas for a once monthly food and wine tasting evening in the town where I live. You wouldn’t believe how difficult it was! There were various novelty shaped thermometers which were useless and could only be used to measure luke warm cups of tea and the best I could find in what seemed to be the whole of France was a digital reader which slowly counted up degree by degree and then met a relaxed end at the temperature of the item. Meanwhile, anything you were cooking was burnt to a crisp while you waited! The South of France is beautiful, but it doesn’t always have the necessary tools for my trade to hand! In the end I bought one from a chef supply wholesalers in the UK so jam was still created! It was a frustrating chapter non the less tho!

    Happy temperature measuring! nbso

  • Thanks so much for this post, and for all the great comments. I’m a firm believer in thermometers. I recently moved from Southern CA back to Tucson, and as I was making my traditional pralines, they just weren’t working out, even with two thermometers. Duh. I moved from sea level to 3000 ft. above sea level!

    Thanks for all the great information. And, I made a trip to get an extra candy thermometer just in case. I’ve also blown out a thermometer – in my case, trying to use a meat thermometer for candy (don’t do it!).

  • Loved this post,


  • I feel like I am still in the dark ages. My grandmother showed me how to do candy and fudge using the “dropping a bit into cold water and seeing what it does” method. I hae tried using a candy thermometer but my batches are ususally so small that the bulb either touches the bottom of the pan or is halfway out of the “liquid”.
    I am inspired to try again though.

  • I gave away my candy thermometer when I moved across the country, and miss it dearly! Once I move to San Francisco and have my own kitchen, it’s pretty much on my list of first kitchen essentials.

  • I made a recipe of peanut brittle and suddenly discovered that my candy thermometer seemed to be not working. I pulled it out and saw bubbling in the bottom of it. Now I wonder if some mercury got into my peanut brittle. Can someone answer this for me?

    If the thermometer isn’t registering any temperature or doesn’t seem to be working, then it likely has a crack in it and should be discarded. Also discard any food items that came in contact with the thermometer. -David

  • The thermometer was registering a temperature, but apparently not high enough. I had used it a couple of weeks earlier and it was working O.K. We have eaten some of this peanut brittle and wonder if we need to do something in case we have some mercury in our system. Are there some pills we can take to take care of it, or would the amount be so minimal that nothing is necessary?

    If you believe you’ve ingested mercury due to a faulty or broken thermometer, you should consult a doctor or certified health professional to inquire if any treatment is warranted or necessary. You may also wish to contact the manufacturer as well. – David

  • I’ve had some weird luck with paddle thermometers. I’ve tried two brands, one of which was Taylor, and the numbers came off in my caramel! After one batch the ink was half gone. I replaced the thermometer, and the second one did the same thing. Are all paddle thermometers prone to losing their ink in candy?

    Also, in Paris, you have these awesome glass tube thermometers that come in a plastic cage. I came very close to buying one, but of course they were all in centigrade, not fahrenheit. Alas! I wonder if they are available here in the US? My search has turned up rien.

  • Those are made by Matfer and they’re available on Amazon, although oddly, they’re shown with both the plastic and metal casing, but only the metal one is available.

    I did have a plastic one here in Paris, which I used to cook a batch of caramel, and the plastic melted. Am not sure why, since they are made for professionals, but now I use metal thermometers when I can.

  • Thermometers (in the US, anyway) are often filled with red or blue alcohol solutions these days or other metallic compounds. If you inherited one from mother, that might be an issue. There have been restrictions on place for fever thermometers in some states for a few years, but I don’t think they apply to cooking thermometers…?

    Disposal of mercury thermometers, borken or unbroken, should be done through your town’s toxic/hazardous waste collection dates/sites.

    how to clean up mercury spills:

  • We’ve used all sorts of candy thermometers to make the brittles and toffees we use for our ice cream. Overall, the best experience we have is with an instant digital thermometer we bought at Home Depot for $20. Aim the gun-like contraption at the boiling liquid and pull the trigger. The readout shows on the screen in 1/10’s of a degree and is consistently accurate. Plus, you don’t have to worry about how deep your pan is or condensation or bad light making it difficult to read.

  • Thanks for the tips on the caged thermometers! I looked all over when I returned from Paris and found nothing. The name of the company was a big help!