Overrun is one of the most important quality attributes of ice cream and is defined as the percentage increase in volume resulting from the incorporation of air during the freezing and whipping process. During ice cream manufacture, air is deliberately incorporated into the mix while it is being frozen, producing a foam-like structure in which air cells are dispersed throughout the frozen matrix. These air cells contribute significantly to the body, texture, smoothness, melting characteristics, and overall sensory quality of the finished product. The amount of air incorporated determines whether the ice cream will be dense and heavy or light and fluffy.

Overrun plays a crucial role in determining consumer acceptability as well as the economic value of the product. An optimum level of overrun improves scoopability, enhances creaminess, reduces hardness, and provides a desirable mouthfeel. Conversely, very low overrun results in a compact, hard, and excessively dense product, whereas excessive overrun produces a weak body, coarse texture, rapid meltdown, and a foamy sensation in the mouth. Therefore, maintaining an appropriate level of overrun is essential for achieving the desired balance between quality and production efficiency.

The principle of this experiment is based on the fact that the volume occupied by ice cream consists of both the frozen mix and the air incorporated during freezing. When the ice cream is melted, the entrapped air escapes from the product, causing a reduction in volume. By comparing the volume (or weight) of the aerated frozen ice cream with that of the melted ice cream mix, the amount of incorporated air can be estimated. The difference between these values is expressed as a percentage and represents the overrun of the ice cream. Thus, determination of overrun provides valuable information regarding the efficiency of the freezing process and the expected quality characteristics of the final product.

Commercial ice creams typically exhibit overrun values ranging from 30–100%, depending on the type of product, formulation, and manufacturing process. Premium ice creams generally have lower overruns, resulting in a richer and denser texture, whereas economy products often contain higher levels of incorporated air to increase volume and reduce production costs. Therefore, measurement of overrun is routinely employed in ice cream quality control and product standardization.