Dirty eggs can be washed to reduce the bacterial load. Although this procedure does decrease the bacterial load, washed eggs must always be considered second grades.
Because the egg content shrinks immediately after laying, a negative pressure is built-up inside the egg, forcing the air to enter the egg through the egg-shell pores. This air flow can bring bacteria into the pores when the egg is produced in a dirty environment. At a later stage, the dirt can be washed-off the egg surface by an effective washing procedure, but this will not remove the bacteria from the inside of the pores.
This means that eggs that are dirty immediatly after laying and washed after collections, should still be considered dirty and a potential risk factor for bacterial contamination and bad chick quality.
Good washing procedures use a water temperature of approximately 40oC and a normal dish-washing detergent, in which the eggs are washed for approximately 15 to 20 minutes. After the washing procedure, eggs should be rinsed with clean water and allowed to dry before further storage.
Washing water should be refreshed frequently, as cross-contamination from previous washed eggs is a serious contamination factor.
When washing is done correctly, no down grading of the orginal egg quality should be expected. However, the original quality must be considered as low.
