Would it be possible to add a "Copper Flask" option? It would just have double the capacity of the leather flask, and be made from Copper sheet.
This would help a lot as a mid-game option. I do not go hunting animals that often, so I think that an option for when you start forging would be nice. Since Steel is quite a late-game metal to obtain, I feel that copper would be a good option for mid-game time, since even if you can get access to copper in the early game, you would be hoarding the pieces for tools and the anvil.