In "Boyz Crazy," Stan was stocking up the meat in the Mystery Shack in preparation for a supposed apocalypse. After listening to Dipper's theory on how Robbie was using music to hypnotize Wendy, and then telling Dipper of his own past heartbreak, he eats more of the Brown Meat. He describes it as "apocalicious."
In "Weirdmageddon 3: Take Back The Falls," Stan eats some of the Brown Meat from a can while detailing his plan to hide out in the Mystery Shack.
The Brown Meat is an ambiguously chunky brown meat. They come in standard tin cans, wrapped in a burgundy strip. One side has a brown label with the words, "THE BROWN MEAT" plainly written in uppercase letters.