For a Kelly Kettle, a fire pit, a folding grill or a wood burner at home during a power cut. Wood is the one fuel you may already have and the one most often bought wrongly.
The specification is moisture content, and it should be 20% or below. In the UK, wood sold in volumes under 2 m3 must be certified “Ready to Burn” to that standard. Unseasoned or “green” wood at 40% or more spends most of its energy boiling the water out of itself: it is hard to light, produces far less heat, smokes heavily and coats the flue in creosote.
That makes the cheaper bag of wet logs the more expensive fuel, because you burn more of it for the same dinner.
Hardwood over softwood for cooking. It is denser, so it burns longer and produces a bed of embers you can cook over, which is what you actually want. Softwood lights easily and is gone quickly, which makes it kindling rather than fuel.
Store it off the ground and under cover but not sealed. Wood needs air around it; a tarpaulin wrapped tight is how dry logs become damp ones.
Burning wood produces carbon monoxide like any other combustion, and a stove indoors needs both a working flue and an alarm: carbon monoxide.