Pesto

Pesto is high in FODMAP mainly from garlic (fructans), plus some lactose from cheese. A garlic-free pesto, or just a small amount, keeps it lower in FODMAP.

Pesto is not fermented, but it is blended - which exposes everything at once to air - and then kept open in the fridge. It also stacks aged cheese, pine nuts and garlic, three histamine entries of their own. The date you opened the jar matters more than the date on the lid.

Pesto is basil, oil, cheese, pine nuts and garlic, and only the last of those brings an oligosaccharide. A garlic-free pesto is low here, which makes this one of the easiest sauces to make compliant. This is a PREPARED food, and that is the difficulty on this axis: the oligosaccharides come from whatever went in - onion, garlic, a legume, an added fibre - not from a single plant that could be looked up. The level follows work on fructooligosaccharides in prepared and preserved foods for that reason. The survey behind this ranks by PLANT FAMILY rather than by food: the Compositae highest in total fructooligosaccharide, then the Allium species. A prepared food takes its place from whichever of those went into it - onion and garlic are Allium, artichoke and chicory are Compositae - and the survey names no prepared food itself.

Pesto is blended and then kept open in the fridge, and both halves matter: blending exposes everything to air at once, and an opened jar keeps working for weeks. It also contains aged cheese, which is the larger tyramine contributor of the two.

Pesto stacks basil, garlic, pine nuts and often lemon — four moderate salicylate sources blended into one condiment, which is why it lands above any of its parts.

Pesto does not hide dairy either - pecorino or parmesan is in the recipe by definition, and both are aged cheeses with almost no lactose left. The dairy-free versions exist and taste different; the standard one is low here for the same reason a hard cheese is.

Pesto is basil, oil, cheese, nuts and garlic - nothing with gluten in the recipe. What puts it here is that supermarket versions bulk out the expensive parts with breadcrumb or potato flake, and the cheaper the jar the likelier that is.

Pesto is basil, pine nuts, cheese and oil. Each part is low, and the nuts - the only ingredient that could raise it - are a small fraction of the jar.

Pesto is basil, pine nuts, cheese and oil. Basil is a herb and herbs measure high by weight, but a jar is mostly oil - and the parmesan in it brings calcium that binds part of the oxalate the basil contributed.