MBG portion scaling — formula & factors

Base formula

qty(N) = qty(1 portion) × N × f(category). Not everything scales linearly — strong seasonings and oil compound in large batches, so apply the sublinear factors below.

Factors per ingredient category

• Staples — rice, protein (chicken/fish/egg/tempeh/tofu), vegetables, fruit, coconut milk, milk: f = 1.00 → grams × N (fully linear).
• Strong seasonings — salt, turmeric, chili, sweet soy, sugar, sautéed shallot/garlic: f = 0.90 → grams × N × 0.9.
• Frying oil: f = 0.85 → grams × N × 0.85 (pan surface & absorption do not grow linearly).
• Water/broth/stock: f = 0.90 → grams × N × 0.9, then correct evaporation ±2% per 10 min of boil.
• Whole aromatics (bay leaf, galangal, lemongrass): per batch, not per portion — minimum 1 bunch/leaf per pot.

Buffer & rounding

Add a 5% shrinkage buffer on top of the purchase total (trimming, cooking loss, distribution leftovers). Round to sane purchase units — legumes & spices per 100 g, oil per litre, eggs per piece.

Worked example — N = 2,680 portions (partner kitchen capacity)

• Rice 75 g → 75 × 2680 = 201 kg (f=1.0).
• Chicken 75 g → 201 kg (f=1.0).
• Turmeric 2 g → 2 × 2680 × 0.9 = 4.8 kg (not 5.4 kg — over-seasoning ruins the batch).
• Oil 8 g → 8 × 2680 × 0.85 = 18.2 litres.
• Sugar 20 g (porridge) → 20 × 2680 × 0.9 = 48.2 kg.

Checkpoints

Taste-test at N=50 and N=500 before committing the full run — 0.9 is a safe conservative factor; the cook may shift ±0.05 for local ingredient character. Log deviations in batch notes so the next cycle adjusts.