Making Candy? Calibrate your Thermometer!
Boil some water then put your thermometer in it. If your thermometer reads 212°F/100°C, you’re good to go!
If your thermometer in boiling water reads any temperature OTHER THAN 212°F/100°C, you need to adjust the recipe’s temperature(s) to account for your difference in temperature of boiling water.
Calculate the difference between your boiling point and 212°F/100°C, then subtract the difference if your thermometer reads below boiling point, or add the difference if your thermometer reads above boiling point from/to the recipe’s stated temperature.
Example using Farenheit:
- Candy recipe says to bring sugar and water to 230°F.
- Water boils at 212°F
- At boiling, my thermometer reads 204°F
- 212-204=8, so it is 8°F below boiling point.
- I must subtract 8°F from the recipe’s temperature of 230°F.
- 230-8=222
- I bring my sugar and water mix to 222°F and then kick myself for eating the entire batch of candy before nightfall because it came out so yummy!
Calibrating your thermometer and adjusting the temperature of the candy recipe works exactly the same in Celsius. For example, if your water boils at 97°C, you must subtract 3°C from the candy recipe’s stated recipe.
While there are many charts out there listing what temperature you should use at various altitude ranges, those charts are using both temperature and elevation ranges and do not take into account any inherent variances your particular geography and thermometer has by default.