Roasted coffee beans were extracted with 10 times de-ionized water as much as roasted coffee beans heated to 95 °C, thereby obtaining a coffee extract solution. The thus obtained coffee extract solution was mixed with milk and granulated sugar and further with an emulsifier. Then, de-ionized water was added to the mixture to obtain emulsion. After sodium bicarbonate was added to the emulsion to adjusting the pH, the emulsion was intimately mixed and homogenized at a temperature of 60–70 °C under a pressure of 15 MPa/50 MPa using a high-pressure homogenizer.