He is especially partial to elf meat, but finds dwarf meat, at least he thinks it was a dwarf he fought a drowner for, too stringy. He also has some standards: he never eats children. I guess that is some comfort. During Flowers and Gold, if Geralt asks him about beggartick, Gramps will give him the formula for Perfume. He also keeps a copy of Ain Soph Aur in an old bookcase at his house. If Geralt chooses to spare him, he will provide the formula for Hanged man's venom.