There has always been a need for compact forms of food that you could stuff in a pack for times when you were cut off from resupply and had to make do with only what you had on you, or what you could find locally. The Germans apparently approached this with erbswurst…a compressed ration of pea meal and other things that, when dissolved in a canteen cup full of hot water, allowed the user to make a soup. Personally, it seems rather unappealing to me but I suppose if your stuck in Stalingrad watching your comrades eat dead horses, it might not seem too bad.
Today, of course, we have MRE’s, freezedrieds, and even simple off-the-shelf soup products that are leaps and bounds ahead of the technology that brought us erbswurst. But… it’s an interesting concept. If a person had access to on of those consumer-grade freeze driers you could make some pretty impressive fare. Here are a couple videos on the subject:
It’s not too hard to imagine the plethora of items found in a modern supermarket that might lend themselves to this sort of thing. The trick is to keep the main principles as the fore: compactness, longevity, and nutrition.
This was actually addressed in a product that came out of WW2 …MPF…a fascinating product with a fascinating backstory: A nalgene bottle full of that stuff would probably duplicate (or exceed) the nutritional value of erbswurst and be a tad more versatile. That MPF, by the way, can be replicated at home.
For running out the door on your way to the boogaloo, a bag of a few days worth of freeze drieds takes virtually no weight and very little space. The more hidebound might go with a few tins of meat and that sort of thing. But wandering around a supermarket sometime, with a careful eye, might reveal some interesting choices for the ‘iron rations’ to keep in your gear. But…the Germans did it first, apparently.