Meanwhile, you can check the “freshness” of eggs using the water float test – fill a bowl with cold water and carefully drop in an egg.
- Sinks flat: very fresh.
- Stands upright: 1 to 2 weeks old or so – use soon.
- Floats: probably old, although smelling normal and appearing fine cracked may still be safe.
As eggs get older, air slowly enters through the porous shells causing them to float.
Years before the first expiration date would show up on a carton, home cooks had their own ways of determining whether an ingredient was still good. One of them was my grandmother – half scientist, half kitchen magician. She knew how to test cakes with a toothpick, sense the doneness of pork chops just by touching them and never sullied a drop of bacon fat. But her most useful trick of all?
How to tell if your egg is fresh with just a glass of water.
This old-fashioned “float test” remains one of the easiest, most-reliable methods for determining whether an egg is fresh, slightly less fresh or ready to discard – no special equipment necessary. In this 2025 updated guide, we will explain how it works, how to do it safely at home and how to buy, store (and even pasteurize) eggs with the goal of maximum freshness.
Ingredients & Tools You’ll Need
This isn’t a cooking recipe, but more of an egg freshness experiment you can do in your kitchen science lab.
| Item | Purpose |
|---|---|
| 1/2 The eggs you are testing | |
| 1 large glass or bowl | To hold water for the “float test above” |
| Cold hard water | Densifies to render an accurate result |
| Paper towel | To dry the eggs off after experimentation is complete |
Optional (for safety testing):
A clean plate to crack eggs on for inspection
(refrigerator below 40°F / 4°C) with a thermometer
Step by Step: How to Test Eggs for Freshness
1. Fill a Glass with Cold Water
Use a tall glass or very small bowl with enough depth to fully submerge the egg. Cold tap water is ideal.
2. Gently Add the Egg
Gently drop one egg at a time into the water. You don’t want cracks in it that will make it possible for bacteria to get in, so handle with care and store at room temperature.
3. Observe the Egg’s Position
| Egg Behavior | Freshness Meaning | What To Do |
|---|---|---|
| Flat bottom sinks | Very fresh (laid in the past day) | Good for any use: frying, poaching or baking |
| Sinks but floats or stands on one end | About 1–2 weeks old | Still fresh — good for frying or baking |
| Floats to the top | Old or spoiled | Check for cracks or odor – discard if it smells bad |
4. Double-Check Floating Eggs
So if your egg floats, and it is not cracked, you still can open it to check.
If it smells sulfurous or bad, throw it out immediately.
It probably is safe to eat in fully cooked dishes, like baked goods or casseroles, if it looks normal and smells absent of odor.
5. Wash and Dry (Optional)
If using the egg, dry with paper towel. Never wash store-bought eggs before refrigeration – doing so can strip off the protective coating.
Why the Float Test Works
Eggshells are naturally porous, so air slowly diffuses through them over time.
Because a fresh egg contains very little air, it is denser and sinks.
As the egg gets older, moisture and carbon dioxide slip away through holes in the shell forming an air pocket.
The bigger this pocket becomes, the more buoyant and soon floating it is.
That’s part of why the age-old float test can be so reliable, based on science to tell how old and fresh an egg is – even in 2025.
How To Buy the Freshest Eggs
When you buy eggs, freshness starts at the store. Follow these USDA-backed tips:
- Look at the sell-by or expiration date – select cartons with two to three weeks before that date.
- Examine the shells – steer clear of cracked, sticky or discolored eggs.
- Even sniff if uncertain – a sour or sulfur smell is indication of spoilage.
- Read the Julian date code (the 3 digit number on the carton). It’s feature the day of the year on which they were packed – “001” corresponding to Jan 1 and so on through “365,” for Dec 31.
- Example: “145” would mean the eggs were packed on May 25.
- Search for the blue and red USDA Grade Shield (AA or A) – it signifies quality and safe handling.
- Cool eggs to an internal temperature of 45°F (7°C) or lower within 6 hours.
(Optional) How To Pasteurize Eggs at Home
Should raw or undercooked eggs be in the offing (mousse, Caesar dressing or homemade mayo), pasteurize them safely at home:
- Put eggs in a pot and cover with water.
- Bring water to 140°F (60°C) – use a thermometer to maintain temperature.
- Maintain at that temperature for 3 minutes (for large eggs).
- Drain and cool in cold water.
The eggs are now safe to use in recipes that do not reach an internal temperature of full cooking.
Nutritional Value (Per Large Egg)
| Nutrient | Amount |
|---|---|
| Calories | 70 – 75 kcal |
| Protein | 6 – 7 g |
| Fat | 5 g (mostly unsaturated) |
| Cholesterol | ~185 mg |
| Vitamin D | 6% DV |
| Vitamin B12 | 9% DV |
| Choline | 25% DV |
| Selenium | 28% DV |
Eggs are nutrient-dense – they contain all the essential amino acids and important micronutrients for brain and cell health, but you can’t rely on them as your main source of vitamins A, C or K.
Conclusion
My grandmother didn’t have labels, and she didn’t have digital gadgets, she had her naked senses and her traditions, and a glass of water. Her float-test trick, though, still works fabulously to this day, even as we stand in our modern kitchens equipped with timers and thermometers.
Knowing the science behind the float test can help you maintain food safety, cut down on waste and stay confident in your meals. So the next time you are in doubt as to whether your eggs are still good, shun guesswork and let them take the plunge.
Frequently Asked Questions (FAQ)
Q1. Can you ever eat eggs that float?
Yes, sometimes. A floaty egg is just older; not necessarily bad. Crack it open – if the smell is OK and it looks fine, bake away or use it in full-cooking recipes.
Q2. How long do eggs keep in the refrigerator?
On average 3 to 5 weeks if kept at 40°F or lower.
Q3. Is the float test accurate for all types of eggs (even store-bought and farm-fresh)?
Yes. The hack applies to any and all chicken eggs, since they form air pockets as they get older, no matter where they’re from.
Q4. Is it OK to wash eggs before refrigerating?
No: Washing can potentially strip the shell of its natural protective coating and increase the likelihood of contamination.
Q5. What’s the difference between brown eggs and white eggs?
Only the breed of the hen itself – nutritionally, they are almost identical. The point of color is to gauge ripeness: The brighter and redder the tomato, the riper and juicier it should be.
Q6. Can you freeze eggs to make them last longer?
Yes. Crack eggs and lightly beat before freezing in an airtight container. Best quality 12 months from date of packaging.
Key Takeaways
- Use the float test to test egg freshness instantly.
- Sinks = new, stands = soon-to-use, floats = old.
- When you bring the eggs home, refrigerate them and check for cracks or smells.
- Observe USDA codes and store below 40°F for safety.
- And when you’re in doubt, trust your senses – sight, smell and good ol’ common sense never become old-school.
