Special Techniques & Reference Section
A Guide to Candy Cooking Stages (Temps)
While most thermometers offer an inkling or list of various stages in cooking different types of candy, not all do and few offer the ranges of cooking temps within these stages.
Stage Target Temp Fahrenheit Target Temp Celsius
Jelly 220 104
Syrup 230 110
Fudge 235-237 115
Soft Ball 240 116
Firm Ball 250 121
Hard Ball 260 127
Soft Crack 280 138
Hard Crack 300 149
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How to Calibrate Your Candy Thermometer
In candymaking especially, the first most important item to ensure your success is in using a calibrated thermometer. And not one single model you ever will buy will be calibrated. I know, as I’ve bought probably 30 over the years, from the old-fashioned models to digitals to even lasers. It’s just the nature of the beast, since thermometers are made in one place (often China) and we use them in another, usually at a different altitude and climate.
Calibrating a candy thermometer is typically done using the boiling water method below and it is a good enough method to ensure candy accuracy. Extreme calibration used by A/C contractors and other industries that require absolute temps depends upon consideration of altitude and barometric pressure, but the following method will allow you to basically calibrate your thermometer regardless of altitude and barometer readings.
Fill a large saucepan with water to two inches from the top. Bring the water to a full rolling boil, then attach/insert your thermometer. After ten minutes in the boiling water, take a reading from your thermometer.
If your thermometer reads 212-degrees (F), rejoice – not only are you exceptionally lucky, but you can rely upon it to accurately read your temperatures in cooking.
If your thermometer registers any heat other than 212-degrees (F), you will need to subtract or add degrees to compensate.
For example, if your thermometer registers 210-degrees (F) after boiling in water for ten minutes and you are cooking a fudge to 235 degrees, you must add two degrees to the final cooking temp on that thermometer (i.e., keep cooking until 237 degrees).
Also for example, if your thermometer registers 215 degrees after boiling in water for ten minutes and you are cooking that same fudge to 235 degrees, you must subtract three degrees from the final cooking temp on that thermometer (i.e., stop cooking at 232 degrees).
TIP: As I have several different thermometers I like to use in different pots, etc., long ago I learned to write the temperature differential in indelible ink on the top. One thermometer will be enscribed “+2” and another “+1” and another “-3” and so on.
TIP: If you are using an infrared laser thermometer, you need not stand there for ten minutes aiming the light at that boiling water. Simply aim the laser for 6 to 10 seconds. Most lasers are “guaranteed” to plus-or-minus one degree, but trust me when I tell you it is very important to verify that. I’ve not yet found one closer than 2 degrees in accuracy.
TIP: Make certain the bottom of your thermometer is NOT resting on the bottom of the pot when calibrating OR cooking. This is especially the case for metal-encased rectangular models. In these, the bulb will certainly never touch the pot bottom, but the metal surrounding it will and absorb too much heat. That’s one reason why I don’t use this type…
The Fine Art of Confectionary 
Hello again…I was attempting to calibrate my candy thermometer and in your example you stated “if your thermometer registers 200-degrees (F) after boiling in water for ten minutes and you are cooking a fudge to 235 degrees, you must add two drees…” Should that ‘200’ degrees be ‘210’ degrees? Thank you, Carol
SpinningSugar: EGADS! What a whale of a correction catch you made there, Carol!!!!!!! You are absolutely right that I made a HUGE typo: At Sea Level, the boiling point of water is 212 degrees (F)! Therefore, if you are calibrating your thermometer and water boils at 214 degrees, you know you must add two degrees to the final cooking temp of whatever you are making (Fudge would therefore be 237 degrees (F) ). If your thermometer reads only 210 degrees when boiling in water for ten minutes, you know you must subtract two degrees from the final cooking temp (Fudge would therefore be 233 degrees).
I will make the correction right now and I thank you SO much for bringing this error to my attention!
How should one adjust temps for a thermometer when tempering chocolate at 6000 feet high altitude? Thank you!
SpinningSugar: My apology for taking so long to respond, Feathered Pines, but I just returned home from the family Thanksgiving trek…
Tempering chocolate and candymaking, in general, at high altitudes requires a very simple adjustment and is much easier to accomplish than adjustments in baking, since both tempering and candymaking relies primarily on temperature. I’m sure you know that air pressure decreases the higher in altitude one goes, and water boils at a much lower temperature where you are than where I am here in Texas.
For tempering and candymaking, all you need to worry about is calibrating your candy thermometer. I’m guessing here, but I expect you will find water will boil at around 205 degrees (F) at 6,000 feet. Whatever your final thermometer reading, write down that number, subtract from 212 (degrees for boiling water at sea level) and the difference is the number of degrees you should subtract from each tempering stage or candymaking stage.
For example, if your final calibration reading is 205 degrees for boiling water, you will need to subtract 7 degrees across the board. Specifically for tempering chocolate:
Heat your chocolate to 113-115 degrees (at sea level, it would be 120-122);
Cool down to 72-73 degrees;
Raise to 81-82 degrees for dark chocolate, or 77-79 degrees for milk chocolate.
Just follow my guidelines for tempering chocolate (using your adjusted temperatures determined during calibration) and you should be just fine.
Happiest of holidays ahead to you and yours.
Can I re-cook a carmel batch, which has nuts, that is too soft?
Thank You.
Debbie
SpinningSugar: Yes you can, Debbie. Place 1 1/2 cups of water into a tall saucepan over medium heat, bring to a boil, and add your too-soft caramel. Blend the water well into the caramel, lower the heat to medium-low, and recook the batch to 244 degrees (F) stirring constantly. Pour into a newly-prepared pan and allow to rest from 24 hours before retesting for firmness.
Hi. I LOVE your recipes, thank you! I love to bake and often use duck eggs in my recipes. What would be the difference ratio wise, if I use them in your recipes? I know that duck eggs are larger than chicken eggs, so would I need to reduce the amount of eggs that a recipe calls for? Thanks, Deb
SpinningSugar: I also love duck eggs. Quail eggs, too. While quail eggs are significantly smaller than other eggs, I find typical duck eggs the same size as an average extra-large chicken egg. I would suggest you try using duck eggs as equal substitutions in your recipes and, if there is any failure that I can’t foresee being attributable to the duck eggs, back off on their amounts. To do so in very simplisting of terms, you would whisk the yolks and whites together, measure and mete as needed. Bear in mind wild duck eggs have a much stronger flavor than our commercial chicken eggs (I’m betting you are well aware of that), which will affect flavor. For me, that’s a plus that provides even more richness to a cake batter for example. For others, though, that might pose a taste challenge.
Hello, do you still check the comments on your site?
A year of travel later and I can respond, “Yes.” 🙂
Liquor-filled Sugar Shells:after I dried the potato-starch for 6 hours and I tried to put the forms in ,no matter how careful I am , my forms collapse. If I dont dry the starch ,the form is perfect. What am I doing wrong?
I don’t know, but if the shells form with undried cornstarch, I would advise not drying it. 😉