Mayonnaise is a thick sauce made primarily from vegetable oil and egg yolks. Whitish-yellow in color, it is a stable emulsion formed from the oil and yolks and is generally flavored with salt, pepper, vinegar and/or lemon juice, and frequently mustard. Mayonnaise is one of the basic mother sauces (sauces mère) of classic French cuisine; numerous other sauces can be created from it by adding additional seasonings. For several centuries a handmade delicacy, in the 20th century it became a mass-produced staple condiment eaten throughout the world. There are almost as many theories concerning its origin and its name as there are possible ways of making it.
Mayonnaise is generally made by slowly adding oil to egg yolk, mustard, vinegar, and seasonings while whisking vigorously to disperse the oil into the liquid.  It can be made with an electric mixer, an electric blender, or a food processor, as well as by hand with a whisk or even a fork. Using a whisk or fork, however, involves fairly tedious physical effort. Blenders and food processors are by far the quickest means of making mayonnaise; some people, however, feel that the end result is inferior to a hand-whisked product, particularly in its texture.
Homemade mayonnaise can also be made using raw egg whites, with no yolks at all, at least if it is done at high speed in a food processor. The resulting texture appears to be the same, and – if properly seasoned with salt, pepper, mustard, lemon juice, vinegar, and a little paprika – it tastes similar to traditional mayonnaise made with egg yolks.
- "It would be easy to contend that it isn't used as often as it might be were we [Americans] to consider it a sauce, as the French do, rather than limiting its primary use to moistening and binding canned tuna." Mark Bittman, New York Times article "Don't Hold Back Flavoring the Mayo" in "Dining Out" section, Wednesday, July 4, 2007, page D3 
- "Mayonnaise is an emulsion of oil droplets suspended in a base composed of egg yolk, lemon juice or vinegar, water, and often mustard, which provides both flavor and stabilizing particles and carbohydrates." On Food and Cooking, Harold McGee, Scribner, New York, 2004, page 633
- On Food and Cooking, Harold McGee, Scribner, New York, 2004
- New York Times article "Don't Hold Back Flavoring the Mayo" in "Dining Out" section, Wednesday, July 4, 2007