Emulsify

Emulsification is the process by which fat and water — which naturally repel each other — are forced into a stable, evenly dispersed mixture. Oil-in-water emulsions (vinaigrette, mayonnaise, hollandaise, pil-pil) disperse fat droplets throughout a water-based continuous phase; water-in-oil emulsions (butter, margarine) do the reverse. Stable emulsions require three elements: an emulsifier, mechanical energy, and the right temperature window. Emulsifiers are amphiphilic molecules — they have one end that is attracted to fat and another that is attracted to water — allowing them to coat the interface of each droplet and prevent coalescence. Common culinary emulsifiers include lecithin (egg yolk, soy), mustard proteins, collagen peptides (in pil-pil and braises), casein (cream), and mono- and diglycerides (in commercial foods). Mechanical energy — whisking, blending, shearing — breaks the dispersed phase into small droplets and distributes the emulsifier around each one. Temporary emulsions (a simple vinaigrette, pan drippings stirred with stock) have inadequate emulsifier to coat all droplets permanently and will separate on standing. Permanent emulsions (mayonnaise, aioli, hollandaise) contain enough emulsifier and have small enough droplet size to remain stable indefinitely, provided temperature stays within range. Heat is a critical variable: hollandaise emulsifies between roughly 62–70 °C, above which egg proteins denature and the sauce breaks; butter emulsions (beurre blanc) must stay below the point at which butterfat fully melts out of its semi-crystalline state.

“Add the oil in a thin, steady stream while whisking vigorously to emulsify the dressing into a creamy, uniform sauce.”

• techniquesSauce Making
• ConceptCollagen
• techniquesBeurre Blanc

1. 1.On Food and Cooking — Harold McGee
2. 2.The Food Lab — J. Kenji López-Alt
3. 3.Modernist Cuisine — Nathan Myhrvold et al.
4. 4.McGee on Food and Cooking — Harold McGee

Confidence: high