Berley (aka chum or ground bait), while not normally used as bait on its own, is a key part of attracting fish to your area. As the block of berley melts, it releases chunks of food and flavour into the water, creating a trail of delicious scent for the fish to follow. Onion sacks and berley cages are fantastic for controlling the dispersion rate, so there’s just enough berley in the water to keep the fish interested, but not so much that you’re feeding them directly.