For feeding a group of 10 or more, build a longer horizontal combustion chamber with several pot holes along the top. The pot directly over the riser gets the most heat and each later position gets less, so a three-pot stove lets you boil, simmer and keep warm at once. A stove sized for one small pot cannot heat a large pot quickly, so scale the fire as well as the number of pots.
Part of Rocket Stove Design
Group cooking spreads one fire’s heat along a row of pots, hottest at the riser end and coolest at the far end.
Position Decides The Pot’s Job
The overview recommends this layout for feeding groups of 10 or more. It says the first pot position (directly over the riser) gets the most heat, and each subsequent position gets progressively less. A three-pot design therefore assigns:
- First pot — boil.
- Second pot — simmer.
- Third pot — keep warm.
Worked Example: Scale
The tin-can stove boils 2 litres of water in 8 to 12 minutes (from the overview). Heating 2 L by 80 K takes 2 × 4.186 × 80 ≈ 670 kJ; over 720 s that is 0.93 kW, over 480 s 1.40 kW delivered to the water.
A 20 litre pot needs 20 × 4.186 × 80 ≈ 6,700 kJ. At 0.93 to 1.40 kW that is 6,700 ÷ 1.40 ≈ 4,800 s = 80 minutes up to 6,700 ÷ 0.93 ≈ 7,200 s = 120 minutes. A group stove therefore needs a bigger fire and more fuel flow than the tin-can prototype, not just more pot holes.
Common Mistakes
- Starting the stew in the last pot. It never reaches a boil.
- Overfilling pots. Hot liquid slops onto the fire and the cook.
- Letting the cooking line fill with smoke. A long chamber needs a draft to match; see Smoke Troubleshooting.
Safety
Big pots scald and big fires make big exhaust
Large hot pots tip and scald; set them level on firm supports and keep children away. A group stove burns a lot of fuel, and any smoke it makes carries carbon monoxide, which has no smell. Cook outdoors, or exhaust the stove outside. See Carbon Monoxide Risks.
What’s Next
- Learn next: Fuel & Operation — keeping a long chamber fed
- Combine with: Retained Heat Cooking — finish the food off the fire