Tempeh

Tempeh's histamine concern is straightforward: fermentation is a well-established pathway for histamine production in foods.

• Fermentation-produced histamine — the mold culture used to make tempeh breaks down soy proteins over days, producing biogenic amines including histamine throughout the block; this is the same mechanism that makes aged cheese and cured meats high in histamine

• More histamine than tofu — plain unfermented tofu skips the fermentation step entirely, making it a notably lower-load option if you want to keep soy in your diet

Freshness matters here too — older tempeh that's been sitting longer tends to have higher histamine levels than freshly made.