Ready to drink (“RTD”) beverages are provided that have improved texture and mouthfeel, and a foam layer formed by microwaving the beverage. The RTD beverage does not have significant foam or does not have any foam when the beverage is at room temperature or lower or when poured at room temperature or lower. The RTD beverage forms a foam layer when heated prior to consumption as a hot beverage, such as by heating in a microwave oven. The beverage contains nitrous oxide (N2O) and/or another suitable gas filled at low temperatures, such as temperatures from 2 to 6° C. for example, to dissolve in the RTD beverage. To extend shelf life of the RTD beverages, after gassing the RTD beverages can be subjected to pasteurization or sterilization techniques. The beverages preferably are coffee beverages, such as cappuccinos or espressos.