Yet again! Temperature shows it’s importance in home brewing!
Hydrometers are all set to take readings at specific temperatures. If you’re taking a reading at a lower or higher temperature than what it’s been adjusted to, you just are not going to get the good ol’ reading you want to check that ABV content.
Luckily for must of us home brewers some wizard figured out a way to calculate the adjustment based on temperature used during the reading. AND BETTER YET! The whole council of wizards got together and made tons of online calculators for us to figure out that temperature! ALL PRAISE THE BEER AND INTERNET WIZARDS!!