A method of cleaning and flushing a beverage dispensing system comprising a sealable pressure chamber for receiving a collapsible keg containing a beverage, said pressure chamber having a first connector, said collapsible keg having a second connector for cooperating with and sealing against said first connector, said beverage dispensing system further comprising a fluid pressure source connected to said pressure chamber for pressurising said pressure chamber, a dispensing line, a dispensing valve, and a dispensing device, said dispensing valve being included or accommodated in said dispensing device, said dispensing line defining a proximal end and a distal end, said proximal end being connected to said first connector and said distal end being connected to said dispensing valve, said dispensing valve having a closed and an open position, said open position allowing said beverage to be dispensed from said dispensing valve when said pressure chamber is pressurised, and said closed position preventing said beverage from being dispensed from said dispensing valve, the method comprising the following steps: (i) providing a first cartridge containing a cleaning fluid, (ii) positioning said first cartridge in said pressure chamber and connecting said first cartridge to said first connector, and pressurising said pressure chamber, (iii) opening said dispensing valve and dispensing said cleaning fluid from said dispensing valve, and causing said cleaning fluid to flow from said first cartridge past said first connector through said dispensing line and being dispensed from said dispensing valve, (iv) disconnecting said first cartridge from said first connector after the emptying of said cleaning fluid from said first cartridge, and removing said first cartridge, (v) providing a second cartridge containing a flushing fluid, (vi) positioning said second cartridge in said pressure chamber and connecting said second cartridge to said first connector, and pressurising said pressure chamber, (vii) opening said dispensing valve and dispensing said flushing fluid from said dispensing valve, and causing said flushing fluid to flow from said second cartridge past said first connector through said dispensing line and being dispensed from said dispensing valve, and (viii) disconnecting said second cartridge from said first connector after the emptying of said cleaning fluid from said second cartridge, and removing said second cartridge. (i) providing a first cartridge containing a cleaning fluid, (ii) positioning said first cartridge in said pressure chamber and connecting said first cartridge to said first connector, and pressurising said pressure chamber, (iii) opening said dispensing valve and dispensing said cleaning fluid from said dispensing valve, and causing said cleaning fluid to flow from said first cartridge past said first connector through said dispensing line and being dispensed from said dispensing valve, (iv) disconnecting said first cartridge from said first connector after the emptying of said cleaning fluid from said first cartridge, and removing said first cartridge, (v) providing a second cartridge containing a flushing fluid, (vi) positioning said second cartridge in said pressure chamber and connecting said second cartridge to said first connector, and pressurising said pressure chamber, (vii) opening said dispensing valve and dispensing said flushing fluid from said dispensing valve, and causing said flushing fluid to flow from said second cartridge past said first connector through said dispensing line and being dispensed from said dispensing valve, and (viii) disconnecting said second cartridge from said first connector after the emptying of said cleaning fluid from said second cartridge, and removing said second cartridge.