There used to be a company that sold super-concentrated beer and a kit for rehydrating and carbonating it. It was geared towards backpackers. Unfortunately, it seems they're no longer around.The obvious next product is the "Mix And Chill Beer System", consisting of a small flask of high proof ethanol, a hop shot or two, and a bag of pasteurized beer-like fluidthat all ends up in a carbonation vessel.
Woof...
https://gearjunkie.com/camping/pats-backcountry-beer-review