Thermometer
Japanese: 温度計（おんどけい）
An instrument monitoring fermentation temperature. Accurate readings are the basis of quality control.
In fermentation, temperature determines flavor, making a thermometer essential. Options include stick-type cooking thermometers, digital, and infrared non-contact models.
For amazake, maintaining 55-60°C is critical — a few degrees change saccharification results. In koji making, temperature is measured frequently for profile recording. Even inexpensive digital models work well. The most basic tool converting 'feel' into numbers. Record time and product temperature together during koji making. The temperature curve reveals growth stages. Through repetition, reading temperatures accumulates as personal experience.