Abstract: Disclosed is a coffee making device, comprising a hermetically sealed case, wherein Oxygen in air is widely exchanged to Nitrogen gas and wherein dissolved Oxygen in water, used for brewing coffee, is widely removed and wherein rate of dissolved Nitrogen in said water is increased. Removing Oxygen by flushing Nitrogen gas from a gas cylinder into coffee making device and using diffusers, a faucet-aerator and gas/water pumps to induce diffusion, before brewing of coffee starts in usual way inside coffee making device. Thereafter coffee is stored in widely Oxygen free environment in case of coffee making device, before consumption. An over pressure of approximate 0.3 atm inside coffee making device can be selected to charge water and coffee with nitrogen, simultaneously when removal of Oxygen takes place. A small over-pressure inside case is necessary to prevent any inflow of Oxygen when coffee making device is on.