6 Ageing of Mix

The mix is then aged for at least four hours and usually overnight. This allows time for the fat to cool down and crystallize, and for the proteins and polysaccharides to fully hydrate. Aging provides the following functions:

• Improves whipping qualities of mix and body and texture of ice cream

It does so by:

• providing time for fat crystallization, so the fat can partially coalesce;
• allowing time for full protein and stabilizer hydration and a resulting slight viscosity increase;
• allowing time for membrane rearrangement and protein/emulsifier interaction, as emulsifiers displace proteins from the fat globule surface, which allows for a reduction in stabilization of the fat globules and enhanced partial coalescence.

Aging is performed in insulated or refrigerated storage tanks, silos, etc. Mix temperature should be maintained as low as possible without freezing, at or below 5 C. An aging time of overnight is likely to give best results under average plant conditions. A “green” or unaged mix is usually quickly detected at the freezer.