A beverage apparatus, system and methods for use are provided. The apparatus includes a pressure vessel configured to receive a flexible bag for containing a beverage. A pressure release valve is connected to the bag, and a pressure source connected to the pressure vessel. A temperature adjustment device is also provided to adjust temperature within the pressure vessel. A controller controls the temperature adjustment device and the pressure source to achieve a desired temperature and pressure within the pressure vessel according to a current mode of the apparatus, where the current mode is selected from a plurality of modes.