System for preparing a beverage

A system for preparing a quantity of beverage suitable for consumption, the system comprising:

• an apparatus including a first brew chamber part and a second brew chamber part forming a brew chamber for selectively holding one of a first and second exchangeable capsules, the second exchangeable capsule having a larger diameter than the first exchangeable capsule, and a fluid dispensing device for supplying an amount of fluid, such as water, under pressure to the first brew chamber part, the first brew chamber part having a cavity for selectively holding one of the first and second exchangeable capsules,
• the system further including the second exchangeable capsule, wherein the second brew chamber part includes a central portion and a peripheral portion, the central portion being movable into a first position for forming the brew chamber for holding the first exchangeable capsule and a second position forming the brew chamber for holding the second exchangeable capsule,
• wherein the central portion includes a first sealing member arranged for providing a fluid sealing engagement between the central portion and a portion of the second capsule facing the second brew chamber part when the brew chamber holds the second exchangeable capsule;
• and
• wherein the peripheral portion includes a second sealing member arranged for providing a fluid sealing engagement between the peripheral portion and the first brew chamber part and/or the peripheral portion and a portion of the second capsule facing the second brew chamber part when the brew chamber holds the second exchangeable capsule.