Natto

Natto is among the highest-amine foods in the surveys - the bacterial fermentation that gives it its texture is exactly the process that produces histamine and tyramine. There is no mild version.

Natto is whole soybeans fermented by Bacillus, and surveys of soy products put the fermented ones far above the unfermented. The bean itself is low; what the bacteria do to it over days is the entire difference. Fermented soy is where this axis is decided, and it was measured as such: the level follows a survey of biologically active amines in FERMENTED SOY PRODUCTS. The fermentation is the variable - the same bean unfermented is a different food here.

Natto is whole fermented soybeans, eaten by the beanful. Its nickel is the bean's, untouched by the fermentation - which is worth saying, because natto is often chosen precisely for what fermentation does to everything else in it.

Natto is whole soybeans fermented by Bacillus subtilis, and it is the raffinose-family oligosaccharides of the bean that put it on this axis. Whether fermentation removes them depends on the organism rather than on fermentation itself: among the moulds that make tempeh, Rehms found R. oryzae and R. stolonifer consume stachyose, raffinose and melibiose completely, while R. oligosporus NRRL 2710 - the ordinary tempeh starter - hydrolyses none of them.

Natto is whole soya beans fermented by Bacillus subtilis, and fermentation consumes part of the GOS - but the beans are eaten whole rather than pressed, so more remains than in tofu or miso. Whole plus fermented lands between the two.

Natto is fermented soybeans and nothing else - the beans are gluten-free. The sachet of tare sauce sold in the same pack is usually wheat-based soy sauce, and that is what changes the answer. What a label may promise is set by regulation and not by a recipe: 828/2014 allows "gluten-free" at or below 20 mg/kg, sets the conditions oats must meet, and admits wheat-derived ingredients in a gluten-free food provided the finished product stays under that ceiling. It measures nothing — it says what a food must meet to carry the claim, which is exactly what a food name cannot tell you.

Fermented soybeans with nothing added, so the salicylate stays as low as the bean. The sauce sachet supplied with it may not be.

Natto comes from the soybean, which carries oxalate like any pulse - but the processing matters more than the bean. Natto is the whole bean fermented as it is, with nothing pressed or strained out, so it keeps what the bean had. Oxalate is water-soluble, so what is boiled and drained differs from what is steamed or eaten whole.