Q10 (Temperature coefficient)
Temperature coefficient (Q10)
Japanese: Q10（温度係数）
The factor by which reaction rate increases when temperature rises by 10°C. For most biochemical reactions, Q10 is 2–3.
Q10 is the factor by which reaction rate increases per 10°C rise. For most biochemical reactions, Q10 ranges from 2 to 3, meaning a 10°C increase roughly doubles or triples the rate.
For miso aging, with Q10 = 2, there's approximately a 2-fold speed difference between 25°C and 35°C. Between winter's 10°C and summer's 30°C, the difference reaches 4-8 fold. Seasonal temperature variation giving rhythm to naturally brewed miso's flavor has this chemical basis.
Quick-brewing methods make miso rapidly at high temperatures by maximizing Q10 principles. However, excessive heat denatures enzymes, requiring balance with optimal temperatures. Q10 is a simple, practical guideline for temperature design.