Should Mayonnaise Be Refrigerated After Opening? The Storage Rule Many People Get Wrong

promptly. Because it may contain raw or lightly cooked egg and lacks commercial stabilizers, it has a much shorter storage life. Use pasteurized eggs whenever possible and follow a trusted recipe with sufficient acid.

Why Commercial Mayonnaise Is More Stable Than Expected
Commercial mayonnaise is not simply raw egg mixed with oil.

Manufacturers control:Acidity
Egg pasteurization
Salt concentration
Processing temperatures
Packaging hygiene
The vinegar or lemon juice gives the product a low pH, which makes it harder for many foodborne pathogens to grow. This is why unopened commercial mayonnaise

.