Do Eggs Float In Water? By admin | In 8th Grade , 8th Grade Science Fair Projects , Drinking Glass , Floating and Sinking | On June 4, 2011 Eggs are known to sink in water. According to research, if you put it in a bowl of water and if it sinks to the bottom and stays there, it is about three to six days old. So, eggs that sinks are fresh eggs, right?...