I keep my food barrels in the barn. I have those metal garbage cans holding my food. And those lids fit on very snugly. Every morning I find the lid off and the food broken into. I’ve tried bungee cords, heavy objects on the lid, sharp objects on the lid, tying the lid even tighter with baling twine. No matter what, if a raccoon is hungry and food, or chickens, are available for them to snatch, they will find a way
Been there. Done that!
When we lived in BC we did constant battle with the raccoons and the bears to keep our garbage intact until it got collected. The raccoons always worked through anything I could think of to slow them down. ...however long it took them. The bears just picked up the cans and threw them around until they opened. I spent more time sweeping and raking trash up from all over the street than I care to remember.
Have you considered a small shed you can lock up inside your barn?
Good luck!