Answer:
I'm sometimes white but most often I'm black. I take you there but never bring you back.
Roast, boast, coast, post. What do you put in a toaster?
You seek me out when your hunger's ripe. I sit on four legs and smoke a pipe.
Use me to reward good behavior.
I am the state when a person is holding a person inside
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.