Quick cooling and maintaining a fruit pulp temperature of 34°F are essential for reducing spoilage and extending the shelf life of strawberries. With recent temperature increases and more on the near horizon, it’s critical to remember: strawberries should be cooled within one hour of harvest. As stated in the 1996 UC publication Handling Strawberries for Fresh Market (Mitchell et al.), “Delays beyond one hour reduce the percentage of marketable fruit.”

Growers often refer to a two-hour cooling window, so Figure 2 was eye-opening—percent marketable fruit clearly begins to decline after just one hour. Figure 2 further shows that for every hour of delayed cooling beyond one hour, losses increase at a rate of approximately 8-10% per hour. Temperatures at harvest and during holding also play a role, as does shading harvested fruit. Unfortunately, during peak yields—when high temperatures are also more likely—keeping pick-to-cool times under an hour becomes especially challenging.

Challenging or not, the higher the temperature and the longer the delay to cooling, the more fruit will deteriorate. These principles highlight the importance of re-evaluating cooling practices and investing in strategies that minimize delays, especially during high-temperature, high-volume harvest periods.

Reference:

Mitchell, F. G., Mitcham, E., Thompson, J. F. and Welch, N. 1996. Handling strawberries for fresh market. University of California Division of Agriculture and Natural Resources. Publication 2442.