Miso Master Organic Mellow White Miso is one of our Short-Term miso varieties. These misos have their own unique position in the miso universe; in many ways, this position is the mirror opposite of the Long-Term Aged Misos. Short-Term Aged or Mellow Misos have more rice koji (grain inoculated with aspergillus spores) than soybeans in their ingredient mix because they are designed to ferment quickly as the aspergillus mold moves quickly through the abundant starches in rice transforming them into simple sugars. Short-Term miso also has much less salt in their ingredient mix, thereby retarding the fermentation process much less than in the Long-Term Aged Misos.