Disclosed is a cartridge containing one serving of coffee powder for preparing a coffee beverage. The bottom of the cartridge is provided with a passage covered by a gas-tight foil. The foil is manually removed before the cartridge is inserted into the coffee machine. Between the passage and the coffee powder, a filter element is disposed, preventing coffee powder to escape from the cartridge. The passage shall prevent a hydraulic pressure build-up in the cartridge, which would lead to the formation of froth.