re: The FDA Has Declared a "War on Beer"

If I had to speculate, the FDA probably believes that some micobiological pathogen (fungal or bacterial) will grow on the spent grain from the time the grain leaves the mash tun to the pig farm. One of the best ways to ensure that pathogens cannot grow is to remove the moisture form the grain. They are probably worried that any potential pathogen from the grain can get into a pork food source.

I don't have the data to back it up but this is highly likely and an unfounded worry. The reason there should be no worries, 1. there has been no link of pathogenic contamination from spent grain to the supermarket and 2. when the spent grain leaves the mash tun it is sterilized, therefore if the grain becomes contaminated it going to get contaminated from the brewery to the pig farm.

If the FDA were reasonable, they would make a rule stating that you have 24 hours to get the grain to the pig farm otherwise you'll have to dry it or throw it in the garbage because microbiological contamination probability and growth increases with time.