How to Build a Two-Zone Fire in a Collapsible Grill
The single most useful fire layout for a lidless flat pack grill: hot side for searing, cool side for finishing, and how to size it.
A two-zone fire is coals on one side and few or none on the other. It is how you control heat on a grill with no knobs and no lid. On a collapsible grill like the Slot Grill, it is the layout you'll use most.
How to build it
- Light your charcoal and wait for it to ash over.
- Pour it into one end of the firebox, roughly two-thirds of the length.
- Bank it deeper toward the far end if you want a very hot spot.
- Leave the remaining third empty or with a thin scatter of coals.
- Set and preheat the grates over the whole grill.
How to use it
| Zone | Use it for |
|---|---|
| Hot (over deep coals) | Searing steaks, chops, burgers; browning sausages; charring peppers |
| Medium (edge of the coals) | Chicken pieces, thicker vegetables, kebabs |
| Cool (no coals) | Finishing thick cuts, holding cooked food, escaping flare-ups, warming buns |
Sizing for each grill
The Compact's cooking area is 16.25" × 9", so the cool zone is about a 5" strip at one end. The Full Size gives you 20.5" × 11.25", enough for a generous cool zone or even three zones (hot, medium, cool).
Half grate, half griddle
The Slot Grill's two-piece top lets you put a griddle plate on one half. Put the griddle over the hotter coals for smash burgers or on the cooler end for eggs, onions or toasting buns. See cooking on the griddle plates.
Fire safety on any collapsible grill
- Outdoors only. Burning charcoal makes carbon monoxide, which you can't see or smell. Never use it in a garage, tent, camper, vehicle, boat cabin or under a roof or awning.
- Non-combustible, level ground. Soil, gravel, sand, concrete, pavers or a fire-safe pad.
- Clearance. Away from walls, vehicles, tents, overhanging branches and dry grass. Kids and pets kept back.
- Seated tabs. Check every tab is fully in its slot before you add fuel.
- Water and gloves at hand. Hot steel looks exactly like cold steel.
- Leave it alone until cold. Don't move or take apart a lit or warm grill.
Mistakes new flat pack owners make
- Too much charcoal. A small firebox gets very hot. Start with half a chimney and add.
- No cool zone. Without an empty end, a flare-up has nowhere to go.
- Cooking on black coals. Wait for gray ash.
- Old ash left in. It blocks airflow; empty it before every cook.
- Heavy oil when seasoning. Thin coats cure; thick coats turn gummy.
- Packing it warm. Wait until steel and ash are cold, every time.
The one-minute care habit
Most carbon steel problems come from skipping the last minute of a cook. After the grill cools, scrape the grates, empty the ash, and wipe a whisper-thin coat of oil or Seasoning Balm on the cooking surfaces. Store it dry. That habit is the difference between a grill that darkens into a slick patina and one that shows orange freckles every spring. If freckles do show up, it's not a disaster: see surface rust.
Questions people ask
Why is a two-zone fire important on a lidless grill?
It gives you somewhere to move food when it's browning too fast, and a gentler zone to finish thick cuts without burning the outside.