Just a suggestion, but could drinking cola give you the bottle back? I've been trying to set up a massive production, and that's been holding me back.
I've been trying to, once I'm happy with my base setup, farm massive amounts of fiber to stockpile massive amounts of cola. This entire process, once set up, requires no new resources to be gathered, so long as the bottles/cans were returned. I have a zero-mining setup otherwise; oil for my flamethrower, water for my air, potatoes for my food, simple.
But if cola doesn't return the bottle/can, it hinders my ability to create hundreds of colas, and never sleep again (don't ask why this is my goal in the game, it just is).