Does an egg float or sink in water? This question helps determine an egg’s freshness. Observing an egg’s behavior in water offers a quick and easy way to gauge its quality before use.
The Egg Water Test
Performing the egg water test is straightforward and requires only a few common household items. Begin by filling a bowl or a tall glass with enough cold tap water to fully submerge an egg. Next, gently place the egg into the water. Observe the egg’s position in the water immediately after placing it. Its orientation and depth provide direct clues about its internal state.
Why Eggs Float or Sink
The phenomenon of an egg floating or sinking is governed by density, which changes as an egg ages. A fresh egg is denser than water, causing it to sink. This density is due to its contents having a higher mass per unit volume compared to water.
Eggshells are porous, allowing for gas and moisture exchange with the environment. Over time, as an egg ages, moisture from its interior slowly evaporates through these pores. Air simultaneously enters to fill the vacated space, leading to the gradual enlargement of the egg’s air cell, a small pocket. The increasing volume of air within the egg reduces its overall density, making it more buoyant. An older egg, with its larger air cell and reduced internal moisture, becomes less dense than water and will eventually float.
Interpreting Your Egg’s Position
The position an egg takes in water provides clear indications of its freshness. If an egg sinks to the bottom of the container and lies completely flat on its side, it is considered very fresh and ideal for any culinary application. This horizontal orientation signifies a minimal air cell and dense contents.
Should the egg sink but stand upright at the bottom, or tilt slightly with its narrower end pointing down, it suggests the egg is older but generally still safe to eat. This position indicates that the air cell has expanded somewhat, but the egg’s interior contents remain sufficiently dense. Such eggs are often suitable for baking, hard-boiling, or other dishes.
Conversely, if the egg floats to the surface of the water, it is typically past its prime and should be discarded. A floating egg indicates a substantial air cell, meaning considerable moisture has evaporated and air has replaced it. While a floating egg doesn’t always mean it is spoiled, it signals significant age, and a sniff test after cracking it open can confirm any off-odors.