Good point about the need to process the grains and beans. Here is the author of Nuclear War Survival Skills on the subject:
>Whole-kernel grains or soybeans cannot be eaten in sufficient quantities to maintain vigor and health if merely boiled or parched. A little boiled whole-kernel wheat is a pleasantly chewy breakfast cereal, but experimenters at Oak Ridge got sore tongues and very loose bowels when they tried to eat enough boiled whole-kernel wheat to supply even half of their daily energy needs. Even the most primitive peoples grind or pound grains into a meal or paste before cooking. (Rice is the only important exception.) Few Americans know how to process whole-kernel grains and soybeans (our largest food reserves) into meal. This ignorance could be fatal to survivors of a nuclear attack. Making an expedient metate, the hollowed-out grinding stone of Mexican Indians, proved impractical under simulated post-attack conditions. Pounding grain into meal with a rock or a capped, solid-ended piece of pipe is extremely slow work. The best expedient means developed and field-tested for pounding grain or beans into meal and flour is an improvised 3-pipe grain mill. Instructions for making and using this effective grain-pounding device follow. . . . As soon as fallout decay permits travel, the grain-grinding machines on tens of thousands of hog and cattle farms should be used for milling grain for survivors. It is vitally important to national recovery and individual survival to get back as soon as possible to labor-saving, mechanized ways of doing essential work. In an ORNL experiment, a farmer used a John Deere Grinder-Mixer powered by a 100-hp tractor to grind large samples of wheat and barley. When it is used to grind rather coarse meal for hogs, this machine is rated at 12 tons per hour. Set to grind a finer meal-flour mixture for human consumption, it ground both hard wheat and feed barley at a rate of about 9 tons per hour. This is 2400 times as fast as using muscle power to operate even the best expedient grain mill.
>Whole-kernel grains or soybeans cannot be eaten in sufficient quantities to maintain vigor and health if merely boiled or parched. A little boiled whole-kernel wheat is a pleasantly chewy breakfast cereal, but experimenters at Oak Ridge got sore tongues and very loose bowels when they tried to eat enough boiled whole-kernel wheat to supply even half of their daily energy needs. Even the most primitive peoples grind or pound grains into a meal or paste before cooking. (Rice is the only important exception.) Few Americans know how to process whole-kernel grains and soybeans (our largest food reserves) into meal. This ignorance could be fatal to survivors of a nuclear attack. Making an expedient metate, the hollowed-out grinding stone of Mexican Indians, proved impractical under simulated post-attack conditions. Pounding grain into meal with a rock or a capped, solid-ended piece of pipe is extremely slow work. The best expedient means developed and field-tested for pounding grain or beans into meal and flour is an improvised 3-pipe grain mill. Instructions for making and using this effective grain-pounding device follow. . . . As soon as fallout decay permits travel, the grain-grinding machines on tens of thousands of hog and cattle farms should be used for milling grain for survivors. It is vitally important to national recovery and individual survival to get back as soon as possible to labor-saving, mechanized ways of doing essential work. In an ORNL experiment, a farmer used a John Deere Grinder-Mixer powered by a 100-hp tractor to grind large samples of wheat and barley. When it is used to grind rather coarse meal for hogs, this machine is rated at 12 tons per hour. Set to grind a finer meal-flour mixture for human consumption, it ground both hard wheat and feed barley at a rate of about 9 tons per hour. This is 2400 times as fast as using muscle power to operate even the best expedient grain mill.
https://info.ornl.gov/sites/publications/Files/Pub57110.pdf