Oxygen Absorber
Oxygen absorber
Japanese: 脱酸素剤（だつさんそざい）
A material that removes oxygen from containers. Used for mold prevention and quality maintenance.
Oxygen absorbers are small packets placed inside containers or bags to absorb residual oxygen. Without oxygen, aerobic molds cannot grow.
Used in miso storage bags or for keeping dried koji. Also prevents oxidative discoloration and flavor degradation. Requires combination with highly sealed bags or containers. Like vacuum packing, it is a tool for controlling oxygen. Iron-based and ascorbic acid types exist; iron-based is standard for food. Unused portions must be sealed or they lose effectiveness. Selecting the right size for container volume matters. Small measures greatly improve storage reliability.