How to test your eggs for freshness

Written by Ollie Wilkinson

How to tell if eggs are fresh blog hero image

Fresh egg tests: The good, the bad and the eggly

From shell sniffing to water dipping, there are many ways to check if your eggs are good. But when it comes to testing freshness, it’s important not to put all your methods in one basket. 

Our farm-fresh eggs are delivered an absolute minimum of seven days before the use-by date. But what happens when that toad in the hole you planned on Sunday turns into a takeaway?

Reduce waste and maximise taste, without ever letting a good egg go squandered, with the help of these fresh egg tests…

The methods of testing the quality and freshness of an egg

Rumour has it, when the Spice Girls wrote, “Trust it, use it, prove it, groove it… Show how good you are”, they were singing about the whacky egg tests Mel B would conduct before each pre-performance fry up.

Here are three methods you can use to ensure there’s nothing scary or suspiciously spicy about your own fresh eggs:

  1. 1. The Egg Water Test
  2. 2. The Visual Inspection
  3. 3. The Hearing Test

The fresh egg water test

The water test is the most floated idea you’ll find online. This simple sink or swim experiment requires just two things: water and a cup.

How to tell if your eggs are fresh using water:

  1. 1. Fill a bowl or glass with enough cold water to cover the egg.
  2. 2. Submerge your egg in the water. If it sinks, it’s safe for consumption, because fresh eggs are heavier than water. If it floats, avoid eating it, as it’s most likely rotten and no longer edible.

If an egg sinks to the bottom and lies on its side, it’s certified fresh. If it sinks at a slight angle, it’s not quite as fresh, but still fine to eat. If any eggs float, they’re certified rotters, and you should dispose of them and consider using the eggshells in your compost.

What does it mean when an egg floats upside down?

If an egg floats any side up, we strongly advise against eating it. But that doesn’t mean it has to go to waste, as you can put expired eggs in your compost.

Eggs can be a great fertiliser for your garden, as they decompose naturally and are packed with calcium. However, the smell of expired eggs can be strong (and rather disgusting), so we recommend only composting them in an enclosed bin. If you dump them on an open compost pile, it may attract local pesky wildlife, and your garden will start to smell like a skunk on a diet of brussels sprouts.

Teach your kids about food waste to learn more about sustainably disposing of produce.

Is the egg float test accurate?

We know what you’re thinking: does the egg water test belong in the same category as those dodgy myths about eating spiders in your sleep and elephants being afraid of mice? Don’t worry, the answer is no, because this particular tidbit is backed by solid science.

Eggshells are porous, and air can gradually seep through their pores. The more time that passes, the more air enters the egg, and the more likely they are to float. The foul smell of the egg nearing its expiration date is hydrogen sulfide, which derives from the sulfur in the white. This light gas will also push the egg to the surface of the water.

See, told you. Science.

What happens if you eat a bad egg?

Eggs are a fantastic source of protein and Vitamin D. In the words of BBC Good Food, they are “nutritionally rich, supplying almost every nutrient you need.”

This, of course, is only the case with fresh eggs. Eating a rotten egg can result in a salmonella infection, something you most definitely want to swerve, with the help of our egg-testing methods.

What are the characteristics of fresh eggs?

Eggs are even better at hiding their rottenness than Keyser Soze, H from Line of Duty and The Big Bad Wolf, but there are several methods you can use to tease out their true colours… Without a police interrogation or eaten grandma.

How to examine a shell:

  • • Hold it against bright light and check for air gaps.
  • • Look for the moving shadow of the yolk. The more it moves around as you shake it, the less fresh the egg.

How to examine the inside of an egg:

  • • Check the compactness of the yolk. The larger and flatter the yolk, the less fresh the egg. A yolk usually takes up about one-third of the egg’s volume.
  • • If the white (also known as the albumen) is runny and thin, it may be stale. As carbon dioxide leaks out of an ageing egg, the albumen becomes clearer. You want your egg white to be as thick as your grandma’s gravy and cloudier than a winter’s day in the Lake District.
  • • If you spot a tiny red or brown blemish on the yolk, fear not. These are broken blood vessels that are perfectly safe for human consumption. If anything, they are a sign of freshness, as blood spots tend to fade with age.

When shopping for free-range and organic eggs, look for Laid in Britain accredited eggs and OF&G accredited eggs. These accreditations are awarded to producers, packing stations and retailers who pass stringent tests for:

  • • The health and welfare of their hens
  • • The quality and taste of their produce
  • • The low carbon footprint of their supply chain. 

Quality checks and short supply chains such as these can result in longer shelf life and increased freshness.

Can you hear a rotten egg?

If you shake an egg next to your ear in a quiet room (as you do), you may hear a sloshing sound within its shell. This is the egg’s way of whispering, “I wouldn’t recommend eating me.” 

A swishing sound is a sign that the egg is no longer fresh, but don’t just play it by ear. You should never rely on this test alone, but it can be used in combination with the water or visual test.

How to store eggs for maximum freshness

Storing your Modern Milkman eggs in their original, recyclable packaging will help remind you of their best before date. The plastic free box will also prevent bacteria and flavouring from other foods from seeping through the eggs’ pores.

Should I keep eggs in the fridge?

Eggs last longer if you keep them at a consistent temperature, so the best way to ensure even the last one in the box isn’t a rotten egg is to keep them in the fridge or pantry. If you’ve already cracked open your egg and don’t want to waste the white or yolk, store them in an air-tight container in your fridge and use them within a few days.

Can you freeze eggs in the shell?

Eggs can be frozen, but only out of their shell. If you store a whole egg in the freezer, the white and yolk will expand and eventually break out of the shell. 

If you have spare whites or yolks that are still in date, you can avoid food waste by freezing them in an airtight container for up to 12 months, although we’d recommend consuming them within four months for maximum freshness. 

Yolks on their own should be frozen with a teaspoon of sugar or salt, as this will prevent them from gelling.

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