Scale a community kitchen from the 100-person figures by headcount for vessel volume, seatings and fuel, but not for floor area or staff, which have fixed minimums. A single 15-gallon pot serves about 100 people at roughly 0.57 litres each, so 30 people need about 17 litres and 150 people about 85 litres, which is more than one pot.
Kitchen scaling is the adjustment of vessel sizes, seatings, floor area, staffing and fuel when the same design is used for a smaller or larger community than the one it was drawn for.
Only Some Quantities Scale With Headcount
The parent guide gives its dimensions for a community of 100 and describes the target range as 30-150. It does not give separate figures for 30 or 150. What follows is proportional extrapolation from the parent’s 100-person numbers, marked as such, plus an account of which quantities should not be extrapolated at all.
Scales with headcount: the volume of food to heat, the number of servings, the fuel burned, the number of seatings.
Does not scale in proportion: the number of sinks and basins (one three-basin sink is the minimum for any kitchen), the number of people on a duty team (a team cannot be smaller than its roles), the size of the smallest useful oven, and the fixed counter and wash space every kitchen needs.
Worked Example: Vessel Volume
The parent guide says a large rocket stove can heat a 15-gallon pot to boiling, “enough for stew, soup, porridge, or boiling water for 100 people in one batch.”
- 15 US gallons × 3.785 L per gallon = 56.8 L.
- 56.8 L ÷ 100 people = 0.57 L per person per batch. This is the working ratio.
- For 30 people: 30 × 0.57 = 17 L, about 4.5 gallons, which fits the parent’s 5-gallon pot size.
- For 150 people: 150 × 0.57 = 85 L, about 22.5 gallons. The parent’s largest vessels are 10-15 gallons, so 150 people need at least two pots, not one larger one.
Proportional Extrapolation Of The Parent’s Figures
| Quantity | 30 | 100 (parent) | 150 |
|---|---|---|---|
| Vessel volume per batch (derived above) | 17 L | 57 L | 85 L |
| Seatings of 50 (parent: two of 50 easier than one of 100) | 1 | 2 | 3 |
| Building area, proportional to 600-800 sq ft | 180-240 sq ft | 600-800 sq ft | 900-1,200 sq ft |
| Cooking wood, proportional to 70-100 lb a day | 21-30 lb | 70-100 lb | 105-150 lb |
The area and wood rows are straight multiplications (× 0.3 and × 1.5) and should be read as a first draft. For the kitchen the proportional area is probably too small, because the sink, hearth and work table do not shrink with the headcount; for 150 it is probably about right or slightly generous. The bread oven is the clearest exception: its wood is per firing, not per person, and one firing does not get cheaper for 30 people (Bread Ovens).
Method: Scale A Plan
Step 1: Fix the headcount you will feed at the busiest time, including children, not only adults.
Step 2: Scale vessel volume by headcount using the 0.57 L-per-person working ratio, then round up to whole pots, because a half-full pot scorches and a too-large pot cannot be moved.
Step 3: Decide the seatings from the dining room, not the kitchen. Fifty at a time is the parent’s workable unit.
Step 4: Set the minimum fixed items regardless of size: a three-basin sink, a handwashing station at the entrance, a separate raw-meat area, a stove with a flue.
Step 5: Re-test the staffing. The parent uses 4-6 people a day for 100, as 2 cooks, 2 prep and wash, and 1-2 servers (Social Dynamics and Rotation Systems). Do not divide that by headcount: at 30 people, two cooks and two on prep and wash is still the sensible minimum.
Common Mistakes
- Multiplying every figure by the headcount ratio. This gives a 30-person kitchen with a quarter of a sink.
- Buying one huge pot for 150. It is heavy, slow to heat, and a scald hazard; two mid-size pots are safer.
- Planning for the average day. The kitchen must also feed everyone on the day the whole community eats together.
Safety
A full large pot is a weight and a scald, not just a volume
56.8 L of water weighs about 57 kg before the pot is counted. Never lift or carry a pot of that size full: ladle it out, or tilt it only with a frame designed for it, and keep children out of the cooking zone. Burns are cooled at once under running water (Thermal Injury Care).
What’s Next
- Learn next: Large-Vessel Cooking — how to handle the pots this page sizes
- Combine with: Ingredient Scaling Formulas — scaling the food as well as the equipment