Egg Salad

Egg salad keeps 3–4 days refrigerated and does not freeze — mayonnaise breaks and egg whites turn rubbery.

Keep it in a covered container at the back of a cold shelf, and serve from a spoon rather than leaving the bowl on the table. At a picnic or buffet, the two-hour limit applies to total time out, cumulatively, and drops to one hour above 90°F. Nest the serving bowl in ice.

Start with cold ingredients. Mixing warm just-boiled eggs into mayonnaise puts the whole bowl in the growth range before it ever reaches the fridge — chill the eggs completely first.

If you are making it ahead for an event, refrigerate it in a shallow container so it stays properly cold throughout, and take out only what will be eaten within the hour.

Egg salad is where one of the most persistent food myths gets it exactly backwards.

Mayonnaise is not the dangerous part. Commercial mayonnaise is made with pasteurized eggs and contains vinegar or lemon juice, giving it a pH around 3.6–4.0 — acidic enough that it is mildly antimicrobial. Adding commercial mayonnaise to a salad slightly lowers the overall pH and if anything inhibits bacterial growth. Homemade mayonnaise made with raw eggs is a genuine exception, but that is not what is in most bowls.

The actual risk is the eggs and the handling. Hard-boiled eggs have lost the antimicrobial lysozyme and the shell barrier that protected them raw, leaving a moist, neutral-pH, protein-rich food. Chopping them involves extensive handling, and Staphylococcus aureus from hands is the classic contaminant — it produces a heat-stable toxin, though egg salad is not reheated anyway.

So the picnic outbreaks blamed on mayonnaise for a century were really about eggs, chicken, potatoes, and pasta sitting warm for hours while being repeatedly handled.

Discard on a sour or sulfurous smell, a watery layer that has separated out, any sliminess, or discoloration. And discard on time regardless: past four days, or past two hours out, it goes.