How Do We Freeze Ice Cream? is a free article published in the July 2018 of NSTA’s Science Scope journal detailing a 5-day investigation of endothermic and exothermic reactions. The first part of the investigation involves stations of chemical reactions to determine whether they are endothermic or exothermic. Students combine the chemicals and analyze data to make this determination. The second part of the investigation is an engineering design challenge in which students design a device that uses an endothermic reaction to lower the temperature of homemade ice cream in five minutes. Both investigations use readily available materials.