An unfilled liquid reservoir for use as part of a dispenser for dispensing pharmaceutical or cosmetic liquids, including an outer housing for placing on a dispensing head of the dispenser and a flexible bag arranged within the outer housing for receiving liquid before the dispensing process. The bag has an opening for removing the liquid, and an intermediate region between the outer housing and the bag is connected to a surrounding area by a ventilation opening which passes through a wall of the outer housing. The flexible bag is provided in a stowed storage state in which the inner volume of the bag is maximally 10% of the maximum inner volume of the bag within the outer housing.
