Contents
An emulsion of oil in egg yolk, held together by the lecithin and proteins in the yolk, sharpened with vinegar or lemon. It does two distinct jobs in cold food and it is worth keeping them separate: it binds a salad, and it waterproofs bread.
The myth worth killing
Mayonnaise is not what spoils a picnic. Commercial mayonnaise is made with pasteurised egg and acidified to around pH 4.0 — below the level at which Salmonella and most spoilage bacteria can grow. It is a more hostile environment than the chicken, egg or tuna it is dressing. What spoils a bound salad is the protein in it, held in the danger zone; the full rule is on Cold Meals.
Homemade mayonnaise with raw egg is a genuinely different case and should be treated as a two-day fridge item.
Types
- American style (Hellmann's, Duke's) — neutral oil, distilled vinegar. Duke's has no added sugar, which is why it is the Southern default for a chicken salad sandwich.
- Kewpie — Japanese, made with yolks only plus rice vinegar and MSG. Richer, tangier, distinctly savoury. The right choice for cold rice bowl and tamago sando.
- Aioli — properly garlic and oil emulsified without egg; in most shops, a garlic mayonnaise.
Making it
One yolk, 1 tsp Dijon, 200 ml neutral oil added drop by drop then in a thread, finished with lemon or vinegar and salt. If it splits, start a fresh yolk in a clean bowl and beat the broken mixture into it a spoonful at a time. Everything at room temperature; a cold yolk is the usual cause.
Keeping
Commercial, months unopened, 2 months refrigerated after opening. Homemade, 2 days.
Elsewhere on the site
Used in: chicken salad sandwich · tuna salad sandwich · egg salad sandwich · cold rice bowl · banh mi
Related: greek yogurt · dijon mustard · hard-boiled eggs · sauces · seasonings and condiments