Miso Master Organic Traditional Country Barley Miso is considered a Long-Term miso. It is aged naturally without temperature control for 18 months through four seasons in giant four-ton, hand-crafted Cypress, Redwood, or Fir barrels. It has a high soybean content in relation to the barley koji (grain inoculated with aspergillus spores). Because soybeans are much more difficult to ferment, with their high protein and fat content, than the high-carbohydrate grains, this miso variety requires a prolonged aging period. This gives the aspergillus spores and lactobacillus bacteria sufficient time to completely break down the complex protein and fat molecules into their more digestible constituents.