<human>:  Did eggs need to be kept cold in the middle ages?
<bot>: No, eggs did not need to be kept cold in the Middle Ages. When eggs are freshly laid, they are covered in a film called a 'bloom.' Eggs with their bloom intact are able to stay at room temperature for one month. Pasteurization destroys the bloom on eggs. Pasteurization was introduced in the 1990's. Pasteurization was introduced in the 1990's.