Culinary Fundamentals, Food Science, and Nutrition
Core concepts
A sous chef must command the "why" behind technique: the Maillard reaction and caramelization (both require low moisture and heat, but Maillard needs amino acids plus reducing sugars), protein denaturation and coagulation, starch gelatinization and retrogradation, emulsion stability (vinaigrette vs. hollandaise), and the gluten network. Know mother sauces and their derivatives, the stages of yeast and laminated doughs, and standard cuts (brunoise, julienne, chiffonade) by dimension. Nutrition literacy matters for menu labeling and allergen work: macronutrient energy values (carbohydrate and protein 4 kcal/g, fat 9 kcal/g, alcohol 7 kcal/g), the major allergens, and the difference between a food allergy and intolerance.
Traps
Questions love edge cases: overcooked green vegetables turning olive-drab (acid plus heat drives chlorophyll degradation to pheophytin); seizing chocolate from a single drop of water; and the myth that searing "locks in" juices (it does not-it builds flavor via browning). Watch for confusion between gelatinization (heat plus water thickens starch) and retrogradation (cooling causes staling). Allergen questions often hinge on cross-contact versus deliberate ingredient.
Worked example
A sauce breaks. Rule of thumb: an emulsion fails when the dispersed phase outruns the emulsifier. To rescue a broken hollandaise, start a fresh yolk-and-water base and whisk the broken sauce back in slowly; for a vinaigrette, a small amount of mustard or lecithin restores stability. Always add oil in a thin stream to keep droplets small.