Pantry Staples

Mayonnaise

Mayonnaise is an emulsion of oil suspended in tiny droplets throughout egg yolk and an acid, held together by the yolk's lecithin, which is exactly why it's genuinely more perishable than a purely acidic or sugary condiment.

Commercial mayonnaise is formulated with enough acidity, typically from vinegar or lemon juice, to be shelf-stable unopened for months, though its egg content still means more cautious handling once opened than a condiment without eggs.

It was reportedly created in the 18th century, though its exact origin is disputed among several competing culinary legends, with the French Basque town of Mahón commonly cited as the namesake source.

Aioli, a traditional Provençal and Catalan sauce built from garlic pounded with olive oil (and, in many modern versions, egg yolk as well), is closely related to mayonnaise in technique but traditionally relies on garlic itself for much of its flavor and body, rather than treating garlic as a mere mix-in to a finished mayonnaise base.

Japanese Kewpie mayonnaise, distinct from a standard American jar, is made with only egg yolks rather than whole eggs and typically includes rice vinegar and a touch of MSG, giving it a noticeably richer, tangier, more savory flavor that's become popular well beyond Japan as an ingredient in fusion cooking.

Classic mayonnaise-based salads — potato salad, egg salad, tuna salad, and coleslaw among them — all lean on mayonnaise's role as both a binder and a flavor carrier, and because these salads combine mayonnaise with other perishable ingredients (cooked egg, cooked potato, raw cabbage), they should be treated with the caution of whichever component in the mix is most perishable.

Light or reduced-fat mayonnaise achieves its lower calorie count mainly by replacing a portion of the oil with water and a stabilizer (commonly a starch or gum), a reformulation that also changes its shelf stability somewhat compared to full-fat mayonnaise's simpler oil-egg-acid emulsion.

Making mayonnaise from scratch by hand, whisking oil into egg yolk and an acid drop by drop, demonstrates just how physically delicate the emulsion is — adding the oil too quickly at any point is the most common reason a homemade batch "breaks" into a separated, oily mess rather than staying smooth.

A broken mayonnaise, whether homemade or an odd batch that's separated in the jar, can often be rescued by whisking a fresh egg yolk in a clean bowl and very slowly drizzling the broken mixture back into it, essentially restarting the emulsion process using the already-flavored, already-seasoned failed batch as the new oil component.

Vegan mayonnaise substitutes typically replace egg yolk's emulsifying role with aquafaba (the liquid from canned chickpeas) or a plant-based lecithin, and while the flavor and texture can come impressively close to traditional mayonnaise, the underlying chemistry — protein and lecithin stabilizing tiny oil droplets — is the same basic principle either way.