What reasons are there for changing Wonderbag's construction from using polystyrene to chipped foam? It seems like the original insulation was a great way to reuse a substance that doesn't decompose, so why the change? Was cooking in a Wonderbag with polystyrene toxic?
Wonderbag is definitely not no electricity/ gas/propane wood or whatever food heating method you choose. You need to bringing your food to a boil by conventional means, then you transfer your dish into the heavily insulated bag.
