Note from Shannon: Please welcome Suzanne, Cultures for Health Customer Service Rep and Cultured-Kitchen Keeper.
For making cheese and yogurt, there’s no more important tool than your thermometer. There are more expensive digital thermometers out there, but often the basic thermometer does the trick just fine. It’s a good idea to test it periodically, just to be sure you’re getting a good reading, especially if the thermometer has been dropped or banged around a bit. If you are storing the thermometer in a drawer with other utensils, find a more secure spot for it, to prevent damage.
Here’s how to test and calibrate your trusty thermometer…
One simple test for your basic thermometer involves a pot of boiling water. Once the water reaches a rolling boil, measure the temperature. Your thermometer should read 212ºF (100ºC).*
If it does not, first check how much of the probe you have submerged in the water. Just the tip won’t do it, the thermometer should be submerged about 1.5 inches, depending on the model, to get an accurate reading. Wait about 30 seconds with the probe properly submerged, before reading the dial.
If your thermometer is off more than a degree or two in either direction, you may need to make some adjustments. Look for the nut underneath the dial. It can be adjusted with a pair of pliers in either direction.
Submerge the probe at least 1.5 inches into boiling water and wait about 30 seconds for a proper reading. Without removing the thermometer from the boiling water, turn the nut clockwise to move the dial clockwise (or counterclockwise to move it counterclockwise) until the dial reads 212ºF (100ºC)
That’s it! Super simple. And now you’re ready to make yogurt.
*Note: With each 500-feet increase in elevation, the boiling point of water is lowered by just under 1°F. At 7,500 feet, for example, water boils at about 198 °F.