Egg Freshness & Float Test Guide: Is Your Egg Still Safe to Eat?

The egg float test is one of the most widely searched food safety topics — and for good reason. Eggs don't come with a clear visual indicator of freshness beyond the best-before date printed on the box, and most people with laying hens don't have a printed date to go by at all. This guide explains what the float test tells you, what it doesn't tell you, and how to combine it with storage information for a reliable freshness verdict.

Four float test outcomes are covered: sinks and lies flat (very fresh, under 1 week), sinks but tilts or bobs (still good, 1–2 weeks), stands upright on the bottom (use soon, 2–3 weeks), and floats (discard). Selecting your result alongside the number of days since laying and your storage method gives a colour-coded verdict: green for safe, amber for use soon, red for discard.

A science explainer describes why eggs change buoyancy over time: as moisture evaporates through the porous shell, the air cell at the wide end expands. Older eggs are less dense and float. This is entirely normal and does not indicate spoilage — but floating eggs are old enough that they should be cracked into a separate bowl and sniff-tested before use.

UK-specific guidance notes that unwashed eggs retain their natural bloom (cuticle) and can be safely stored at room temperature for several weeks, unlike commercially washed eggs which must be refrigerated.

Float test guidance is drawn from USDA food safety resources, the Food Standards Agency (UK), and research published in Poultry Science. UK room-temperature storage guidance reflects FSA advice that unwashed eggs do not require refrigeration and that the bloom prevents bacterial penetration through the shell.

Fill a bowl or glass with cold water. Gently lower the egg in. Observe the result and select it from the dropdown. Enter the approximate number of days since the egg was laid and select your storage method. The calculator will return a freshness verdict and a recommended action. When in doubt with a borderline egg, crack it separately and check for unusual smell or appearance before deciding.