Shelf-Life: A Story About Fresh Bakery Transport
Mom and Pop Bakery baked exceptional cakes. Local demand was high. Mom and Pop wanted to increase sales by expanding. Unfortunately, their delicious cakes had a shelf life of three days. A three-day shelf life left no time to ship the cakes. How could they keep their quality and simultaneously get longer shelf life? Water activity is the answer.
Water activity is a well-known predictor of microbial growth.
As Kimberlee J. Burrington writes in Food Product Design (Aug. 1998), "Development of many baked products involves maximizing moisture content to produce the best possible eating qualities while minimizing water activity. Lowering the water activity increases product stability in terms of susceptibility to microbial growth."
Lowering your water activity
You can reduce your product's water activity in several ways. Adding humectants like salt and sugar 'binds' the water in the product.
You haven't reduced the water content, but you have reduced the water activity.
You can also lower water activity by lowering the temperature of the product. Drying your product is another possible solution. In many cases, a minor recipe change can bring water activity to a safe and shelf-stable level.
Back to Mom & Pop
Mom and Pop solved their problem with a minor change. They manipulated their recipe while keeping an eye on the changing water
activity. The final product kept all the tastiness of the original but with a lower water activity. Their new 9-12 day shelf life made
shipping-and successful expansion-possible.