Your plate is never a single ingredient
Look at any Italian restaurant menu and check the mains: "Beef tagliata with rocket, confit tomatoes and Parmesan shavings." What the customer reads as one dish is actually an assembly of 3-4 distinct components, each with its own ingredients, waste factors and cooking yields.
This is a composite dish. And if you calculate food cost by simply multiplying raw ingredient weight by price per kilo, you are working with a fictional number — one that is 20-30% lower than reality.
The reason is straightforward: meat loses weight during cooking, vegetables have inedible parts you discard, the sauce is a recipe within a recipe with its own costs. Ignoring these steps means pricing based on false data.
Sub-recipes: the recipe inside the recipe
A sub-recipe is an intermediate preparation that enters as an "ingredient" in one or more final dishes. The ragu in lasagna, the bechamel in crepes, the stock in risotto.
Sub-recipes matter because each one has its own cost per gram of finished product, can be reused across multiple dishes, and has its own cooking yield. If you don't treat sub-recipes as separate cost entities, every dish containing them carries an incorrect food cost.
Cooking yield and waste factors
Cooking yield (how much weight remains after cooking):
- Beef steak on grill: 75-80% yield (loses 20-25%)
- Roast veal: 70-75% yield
- Confit tomatoes (slow oven): 50-60% yield
- Boiled octopus: 50-55% yield
- Wilted spinach: 30-40% yield
- Dry pasta: 180-200% yield (absorbs water)
Waste factors (inedible parts removed before cooking):
- Whole fish to fillets: 40-55% waste
- Shellfish to flesh: 50-60% waste
- Bone-in meat to boneless: 20-35% waste
- Standard vegetables: 10-20% waste
- Artichokes: 55-65% waste
The formula for each component:
- Net cost per kg = Purchase price / (1 - waste %)
- Cooked cost per kg = Net cost per kg / Cooking yield
- Portion cost = Cooked portion weight x Cooked cost per kg
Worked example: Beef tagliata with rocket, confit tomatoes and Parmesan
Selling price: EUR 24.00.
Component 1 — Beef sirloin tagliata (main) Purchase: EUR 28.00/kg, 10% waste, 78% cooking yield. Net cost: EUR 31.11/kg. Cooked cost: EUR 39.88/kg. Cooked portion: 180g. Cost: EUR 7.18
Component 2 — Dressed rocket (side) Rocket 40g, olive oil 8ml, lemon juice 5ml. Cost: EUR 0.43
Component 3 — Confit tomatoes (garnish, sub-recipe) Batch: 1kg cherry tomatoes + oil + garlic + thyme = EUR 6.48 raw. Cooking yield 55% = 607g finished product. Cost per gram cooked: EUR 0.01068. Portion 50g. Cost: EUR 0.53
Without cooking yield, you would have estimated EUR 0.29 — almost half the real cost.
Component 4 — Parmesan shavings 20g at EUR 18.00/kg with 15% rind waste = EUR 21.18/kg net. Cost: EUR 0.42
Total plate cost: EUR 8.56 Food cost: 8.56 / 24.00 = 35.7%
Without waste and yield corrections, the cost would appear to be roughly EUR 6.50 — a food cost of 27.1%. That 8.6 percentage point gap, applied to 30 portions per day, adds up to roughly EUR 22,600 per year in margin you thought you had but don't.
Worked example: Lasagna with three sub-recipes
A 12-portion tray with ragu bolognese, bechamel and fresh pasta.
Sub-recipe A — Ragu (beef + pork mince, tomato, soffritto, wine): EUR 18.40 raw, 70% cooking yield = 1,590g finished. Cost: EUR 0.01157/g.
Sub-recipe B — Bechamel (milk, butter, flour): EUR 2.47, ~100% yield, 1,160g. Cost: EUR 0.00213/g.
Sub-recipe C — Fresh egg pasta: EUR 1.75 for 800g. Cost: EUR 0.00219/g.
Assembly per tray: 1,200g ragu (EUR 13.88) + 900g bechamel (EUR 1.92) + 750g pasta (EUR 1.64) + 200g Parmesan (EUR 4.24) + butter (EUR 0.24) = EUR 21.92 total, EUR 1.83 per portion.
At EUR 12.00 selling price: food cost 15.2% — excellent margin typical of traditional Italian first courses.
Common mistakes
- Using raw weight as cooked weight — 180g raw beef becomes ~140g cooked
- Never weighing finished sub-recipes — without knowing how much finished ragu you produce, cost per gram is a guess
- Ignoring cooking oil absorption — fried items absorb 10-15% of their weight in oil
- Dismissing "small" garnishes — Parmesan shavings, truffle oil, toasted pine nuts add up fast across hundreds of services
How BiteBase handles composite dishes
In BiteBase, every sub-recipe is a full recipe with its own automatically calculated food cost. When you add it as an ingredient in a composite dish, the cost per gram already includes waste and cooking yield. If a supplier price changes for any ingredient in the ragu, the lasagna's food cost updates automatically. You can drill down from plate to sub-recipe to individual ingredient. No fragile spreadsheet formulas — create the recipe once with accurate numbers and costs stay current with every new supplier invoice.