Freshness

Old eggs are better for boiling, because they are easier to peel (anyone who has ever tried to peel a fresh quails egg will testify to this), but we like to use the freshest eggs we can get our hands on for baking. My mother tells me that when she bought eggs from the itinerant egg man in Teheran she would take a bucket of water to test their freshness. The freshest would sink to the bottom and rotten ones float to the surface (due to the increase in sulphurous gases inside the shell). This technique still holds true and it’s a good test if you are ever in doubt about the freshness of an egg, though these days most have a date stamp.