Do Eggs Need To Be Refrigerated?

Why does the US refrigerate eggs but Europe doesn't?

The US washes commercial eggs during processing to remove dirt, bacteria, and contaminants from the shell surface; European countries generally don't wash eggs commercially. Washing removes the natural protective bloom (also called the cuticle) that fresh eggs have on the shell, which is a thin coating that seals the porous shell against bacteria. Without that bloom, washed eggs become more vulnerable to bacterial contamination and need refrigeration to compensate. European unwashed eggs retain the bloom, allowing them to sit safely at room temperature for several weeks. The US system relies on continuous refrigeration; the European system relies on the natural barrier. Both work when followed consistently, but switching between them mid-supply-chain creates safety problems.

What is the protective bloom on eggs?

The bloom (or cuticle) is a microscopic protein layer deposited on the eggshell as the hen lays the egg. This bloom seals the shell's roughly 7,000 to 17,000 pores against bacterial penetration while still allowing the egg to breathe. Unwashed farm-fresh eggs retain this bloom and can sit at room temperature for 1-3 weeks safely. Commercial US egg washing uses warm water (the eggs must be warmer than the wash water to prevent bacteria from being pulled inside through the pores) plus mild detergent, which strips the bloom. Some farm-fresh egg sellers in the US deliberately don't wash their eggs and recommend room-temperature storage; these are perfectly safe but should be used within 3 weeks.

How long can refrigerated eggs sit at room temperature?

Refrigerated eggs should not sit at room temperature for more than 2 hours, or 1 hour if the room is above 90 degrees F. This is the standard food safety rule for previously-refrigerated perishables: warming creates condensation on the shell that promotes bacterial growth, and bacteria multiply rapidly once warmed. The USDA explicitly warns against this 'warming then re-refrigerating' pattern because each cycle reduces shelf life and increases contamination risk. For shopping trips, get eggs into the refrigerator within 2 hours of purchase (1 hour in hot weather). If eggs have been left out for several hours, discard them rather than putting them back in the fridge. Better to lose the eggs than risk food poisoning.

Can you go from room temperature to refrigeration?

Yes, but only once and only soon after the eggs were laid or purchased. Unwashed farm-fresh eggs that have been at room temperature can safely be moved to the refrigerator, which extends their shelf life to several months. Once refrigerated, they need to stay refrigerated. Commercial US-washed eggs should never go from refrigeration to room temperature and back, since this cycle creates condensation that pulls bacteria through the pores. European unwashed eggs that have been kept at room temperature can be refrigerated for extended storage without issue. The rule is: pick a temperature strategy and stick with it for each egg. Bringing eggs to room temperature briefly before baking (for better texture) is fine if you're cooking them immediately.