Hops is added to the water drained not to the grain, so there shouldn't be hops in your grain. I store our loads in 44-55 gallon barrels and add water as needed to stop the mold process. The top still molds, but I scrap it off when I get to that barrel for use and feed to pigs. That keeps even...
I use spent grain for all my animals and they love it! It's mostly barley and some wheat. I feed it wet and store it wet to stop the chemical reaction from causing mold. Sometimes the process of molding has started on top, but I scrap that off and give to the pigs. In my research, I have found...