Miso soup

Miso is made by fermenting soybeans (often with grains) for months or even years, which is precisely the condition under which histamine builds up naturally.

• Fermentation time — longer-aged misos (like red or hatcho miso) typically have higher histamine levels than shorter-fermented white miso, because more time means more accumulation

• Broth additions — traditional miso soup often includes dashi made from dried fish flakes (katsuobushi), which are themselves a significant source of histamine

White (shiro) miso in a simple vegetable broth tends to be the gentler choice compared to darker, longer-fermented varieties with fish-based stock.