Cookery (Theory): Principles, Commodities and Kitchen Calculations
Cookery (theory) in the UPMSP Class 12 vocational course tests whether you can connect food science to kitchen practice: heat transfer, commodity selection, standard recipes, hygiene and simple cost control. Questions often ask you to classify a method, name a sauce or calculate a portion cost, so learn definitions with an example.
Core rules and concepts
- Method families: moist-heat (boiling, poaching, steaming), dry-heat (baking, roasting, grilling), fat-heat (shallow/deep frying, sautéing) and combination (braising, stewing). Poaching is 70–80°C; boiling is 100°C at sea level.
- Food science: protein coagulates with heat; starch gelatinises in moist heat; Maillard browning needs dry heat plus amino acids and sugars; caramelisation is sugar-only browning.
- Mother sauces: béchamel = milk + white roux; velouté = white stock + blond roux; espagnole = brown stock + brown roux + tomato; tomato sauce; hollandaise = warm egg-yolk/butter emulsion.
- Hygiene: keep high-risk foods out of the 5–60°C danger zone; use colour-coded boards; follow FIFO.
- Costing: edible portion (EP) = as-purchased weight (AP) minus trim; cost per portion = total raw ingredient cost ÷ number of portions.
Worked example
A pulao recipe yields 12 portions: 900 g rice at ₹60/kg, 300 g vegetables at ₹40/kg, 150 g ghee at ₹500/kg. Convert to kg, multiply, then divide: rice 0.9 × 60 = ₹54; vegetables 0.3 × 40 = ₹12; ghee 0.15 × 500 = ₹75. Total = ₹141. Cost per portion = 141 ÷ 12 = ₹11.75. Show units and keep the division to two decimals.
Traps that cost marks
Calling hollandaise a roux sauce; writing boiling for poaching; using AP weight as EP weight; ignoring yield when costing; confusing Maillard browning with caramelisation; naming a derivative sauce without its parent.