A cartridge for storing a flowable substance in a bulk container is disclosed. The cartridge includes a shell having a breakable score line and configured to sit inside the bulk container and a bag positioned within the shell and configured to be filled with the flowable substance. The bag has a port for introducing the flowable substance into the bag and a drain spout in fluid communication with the bag, allowing the flowable substance to be drained from the bag after filling. The breakable score line is configured to separate due to force exerted on the shell as the bag is filled, allowing the bag to expand inside the bulk container. A method of filling a bulk container with a flowable substance using the cartridge is also disclosed.