After the initial preparation, the milk coffee beverages were stored at 5 °C and 40 °C; the emulsion stability was then studied by visual observation. The results are summarized in Table 2. Canned milk coffee prepared by retort sterilization (used for both Rich1 and Rich2) saw little milk separation, and the milk coffee beverages (which are oil-in-water emulsions) were stable regardless of the kinds of roasted coffee beans or storage temperature. However, the plastic bottled milk coffee beverage prepared by UHT sterilization exhibited strong milk separation with Colombian EX under the conditions of LV 20 at 5 °C; however, the 40 °C storage samples had little milk separation. The milk coffee beverage with Indonesian AP-1 had observable milk separation at 5 °C for both Rich1 and Rich2.