Cool water washing slows egg pathogens

Using cold water instead of warm during a second wash of eggs can help cooling, which reduces the risk of pathogen growth both inside and outside the shell.

Researchers with the US Department of Agriculture together with those from Auburn University studied the frequency of salmonella, campylobacter, listeria and other pathogens in eggs commercially washed in cool water. Their findings were reported .

The researchers tested three water temperature schemes in dual washing commercial systems:

• -          The first used water at 120^oF (48.9^oC) for both washes or the eggs
• -          The second used water at 120^oF (48.9^oC) for the first wash and 75^oF (23.9^oC) for the second
• -          The third used water at 75^oF (23.9^oC) for both washes.

Using warm water for the first wash and cooler water in second wash was most effective in terms of reducing egg temperature and microbial levels. While salmonella, campylobacter and listeria were all detected in shell emulsion and wash-water samples from the cool-water washing treatments, none was detected in the eggs contents throughout the storage period of 8 weeks.

Current USDA quality standards require processors to use wash water of at least 90^oF (32.2^oC)