In today’s world of convenience foods and pre-packaged meals, it’s easy to forget the basics—like making sure the eggs in your fridge are still fresh. Using a spoiled egg can ruin a recipe and even pose health risks due to bacteria like salmonella. Luckily, there is a timeless trick passed down through generations that makes checking egg freshness quick and foolproof. Affectionately called Nana’s egg freshness test, all you need is a bowl of water and a few seconds of your time.

The science behind the test is simple. Eggs have a small air pocket inside. As the egg ages, moisture and carbon dioxide slowly escape through the porous shell, making the air pocket larger. If the egg sinks and lies flat, it is fresh. If it sinks but stands upright, it is still safe but should be used soon. If it floats, it is old and should be discarded.

To perform the test, fill a clear bowl with cold tap water and gently lower the egg into it. Observe its position. This method is fast, easy, and requires no fancy tools. For best results, refrigerate eggs to prolong freshness, avoid washing them since the natural protective coating prevents spoilage, and discard any eggs with cracks, as bacteria can enter through damaged shells.

Nana’s egg test is more than just a trick—it is a reminder that traditional knowledge still has a place in modern kitchens. In an era dominated by smart gadgets, sometimes the simplest methods are the most reliable. This small habit helps reduce waste by letting you confidently use eggs that are still good. A little common sense and a bowl of water make all the difference.