Mayonnaise
Mayonnaise is the cornerstone of cold kitchen prep (Garde Manger). It is a permanent cold emulsion, meaning that once formed, it should remain thick and creamy even when stored. Where a vinaigrette relies on mechanical force alone, mayonnaise enlists a powerful chemical ally: lecithin.
Found naturally in egg yolks, lecithin is a phospholipid molecule with a dual personality — one end loves water, the other loves fat. When you whisk oil drop by drop into a yolk, lecithin molecules surround each tiny oil droplet, creating a permanent barrier that prevents coalescence. A single yolk can emulsify up to 200 ml of oil. The key is patience: add the first few drops painfully slowly, and only accelerate to a steady stream once the base turns thick and glossy.
History & Origins
Named after the port of Mahón in Menorca, Spain. Legend says that after the French captured the city in 1756, the Duc de Richelieu's chef created the sauce to celebrate, substituting oil for cream in a traditional sauce when cream was unavailable.
The Science
Lecithin, a phospholipid found in egg yolks, is the magic ingredient. One end of the lecithin molecule is 'hydrophilic' (loves water) and the other is 'lipophilic' (loves fat). It forms a protective barrier around oil droplets, preventing them from merging, even at room temperature.
Technique
Temperature is key. Egg yolks at room temperature emulsify more easily than cold ones. If the mayonnaise is too thick, a teaspoon of warm water can help 'relax' the structure and allow more oil to be incorporated.
Common Mistakes
The 'Greasy Breakdown'. Adding oil faster than the lecithin can coat the droplets results in a thin, oily mess. If this happens, don't toss it. Start with a fresh yolk and slowly whisk the broken mixture into it.
Chef's Notes
A dash of boiling water at the very end (the 'Le Petit' trick) can help pasteurize the yolks slightly and stabilize the emulsion for longer storage.