The float test, crack test and sniff test — how to tell if eggs are safe to eat.
⏱ 2 min readEasyUpdated June 2026
Quick Answer
The float test: place the egg in a glass of cold water. Fresh egg sinks flat. Week-old egg tilts up. Old egg floats — discard it. A floating egg has a large air cell from gas produced by bacteria, indicating spoilage.
The Float Test (Most Reliable)
1
Fill a glass or bowl with cold water
Use a container deep enough to fully submerge the egg — a tall glass or medium bowl works well.
2
Gently lower the egg in
Place the egg on a spoon and lower it gently into the water rather than dropping it, to avoid cracking.
3
Read the result
Sinks and lies flat: Very fresh. Best for poaching and frying where yolk integrity matters. Sinks but tilts upright or stands on end: Around 1–2 weeks old. Still perfectly good to eat — great for hard-boiling (older eggs peel more easily). Floats: Discard. The egg has spoiled. Do not crack it open — the smell will be unmistakeable and very unpleasant.
The Sniff Test
Crack the egg into a bowl before using (not directly into your dish). A bad egg smells strongly of sulphur. A fresh egg has little to no smell. Any off smell — discard.
The Candle Test (for uncracked eggs)
Hold the egg up to a bright light in a dark room. A fresh egg has a small air cell at the large end. A very old egg has a large air cell and the yolk moves around freely inside. Used commercially to grade eggs but rarely needed at home.
Best before dates vs actual freshnessEggs in Australia have a best before date of 28 days from laying. A properly refrigerated egg is safe to eat for 4–5 weeks past this date — the float test is a more reliable freshness indicator than the printed date. Store eggs in the fridge (not the door, which fluctuates in temperature) for maximum freshness.
Frequently Asked Questions
The egg white becomes slightly more alkaline as an egg ages, which causes it to adhere less to the inner membrane. Very fresh eggs are notoriously difficult to peel — the white sticks to the membrane. Week-old eggs peel cleanly. For hard-boiling, use eggs that are 1–2 weeks old for the best peeling experience. Adding a teaspoon of baking soda to the boiling water also helps with very fresh eggs.
Yes, if it passes the float test and sniff test. The best before date on Australian eggs is a conservative 28-day guide. Properly refrigerated eggs remain safe and good quality for several weeks beyond that. The float test is a more accurate freshness indicator than the printed date. If in doubt, crack into a bowl first — any bad smell means discard.