"This fire will remain burning for X amount of time"

Game Talk The Drawing Board
1

So, there’s that whole exploit regarding being able to boil an entire gallon’s worth of water from the flame of a burning chcolate bar wrapper, I propose a solution:

You can observe a fire to see how long it will remain burning for, and can only craft things that require fire if the fire will burn long enough to meet the crafting time requirement

Example: You light a fire with a burning chocolate wrapper, duration of the fire is ~30 seconds. Boiling a gallon (15 units) of water takes 20 minutes, meaning that the crafting recipe will be locked unless you put more fuel on the fire to increase the duration

Add a two-by-four and maybe the duration goes to around half an hour. You can now craft a half hour’s worth of water

The amount of added duration would be based on the weight of the object added to the fire, with modifiers depending on material (paper burns faster than wood, so a pound of paper would add less duration than a pound of wood, etc)

This is just something meant to fix the exploit with a “nearby fire”

2

I thought about it

It would be hard to do perfectly, since fires are non-deterministic, but approximation could be relatively simple.
We’d probably have to disregard effects like rain starting during crafting. Alternatively fail the craft if the rain kills the fire.