Making Your Own Survival Rations 1: Puffed Grain Cakes

Video courtesy of Popular Science
If you buy a machine to make your own puffed-grain cakes, you can pay hundreds of thousands of dollars and more. But you can make a machine to do the job with spare junk around the shop. In these days of tighter budgets, it helps to know smart ways to trim the fat.

The science behind puffing is simple. Heating the moisture inside of a grain creates pressure and builds up steam, which is trapped by the grain’s hull or shell. When that hull suddenly fails, everything inside it expands in a blast, transforming the grains into a crispy, porous mass; the best example of this is popcorn. Some grains can fuse together, making a cake.

... We built a metal shell using a pipe, a rod and a plate to mount the pipe on, forming a bottom to clamp against, like a piston in a cylinder. Using vise grips, we put the shell over a butane burner, clamped it tightly, and then unclamped it to make it puff. At high temperatures, you have 10 to 20 seconds when the grains puff before they start to burn. We puffed millet, wild rice, sorghum, barley, and white and brown rice. We called the results “vise cakes.”

Our equation for the process looks roughly like this: 150 psi (pressure) and 480ºF (heat) x 12 seconds (time) + sudden release back to atmosphere = 1 vise cake.
Last year we built a rig to make mini vise cakes, which worked well, but it took a long time to produce a large quantity. So this time we increased the scale, creating a design that could make the cakes with a 2.5-inch diameter. All told, it cost us only $57. Our design requires at least four hands to operate, though why puff solo when you can puff in a group? Besides, you‘re saving a good million bucks or so off the price of a commercial machine. _PopSci

Al Fin survival nutritionists are working on something far more sophisticated which they are not allowed to talk about right now, but you can get the germ of an idea about the project here. No more about that, for now.