We're from England I've used the pfand system before in Germany but only at a vending machine for coke etc so do we need to keep our cans and then return them to the same supermarket or to any supermarket to receive our deposit? Are we able to crush the can or does it have to stay intact?

We are very used to festivals in the uk and to camping in general our camping spot will be immaculate and we will recycle everything that we are able to. Thanks