The Idle Thumbs podcast used to talk about "podblasting." I just
came across this:
6. What is 'Pod Blasting' and why do you do it?
One of the most accurate methods to determine peanut maturity is to shell the peanuts and look at the color of the inside of the shell. The darker the color, the more mature the peanut. The most mature will be practically black while the least mature peanut will be pure white. North Carolina State University developed a method of actually sandblasting the outside of the hull, which is faster than shelling the sample. The process removes the outside covering of the shell and reveals the maturity colors you see when the peanuts are actually shelled. After they have been "pod blasted", the different colors are separated and we (Richard Rhodes) determine what percent are ready to dig or how long it will be before we should dig. By waiting and digging 10 days to 2 weeks later, at the optimum time, our yields can increase 3 - 500 pounds per acre or $100 to $150 per acre. On the other hand, waiting too long will cause the pins to shrivel and dry out, causing the peanuts to shed and fall off when dug.