We recently received a question from a Brewer who was using an InkBird for Temperature Control who noted the temperature differences between the InkBird and his Thermometer.
The Thermowell he was using allowed his Thermometer Probe to nearly reach the center of his Fermenter. The Thermometer, which was installed on the side of the Fermenter, and did not measure the center most portion of the wort, read several degrees cooler than the InkBird Temperature.
The batch he was brewing required a specific temperature, which made figuring out why there was a difference in readings that much more important.
Temperature begins to Lower when the Kinetic Energy of the of the Wort Molecules Lowers. The Wort is Alive and Moving. Yeast is Bubbling, and Temperatures are Rising Inside for Biological Reasons. Yeast will produce some Heat Energy.