Before you make that delicious eggy in a basket, make sure you read our tips on how to purchase, store and consume eggs safely.
Recently the national standard for free range egg production has undergone some changes. While the debate continues over the new standard rulings, it has served as a good reminder for safe egg consumption. There are lots of things to look out for when it comes to this incredibly versatile and protein packed food, so we’ve created a list to help you buy, store and consume eggs safely.
Safety tips
- Buy your eggs from supermarkets or shops which store them in the refrigerator or at least in a cool area of the store. Refrigerate your eggs immediately on arriving home – treat them like you treat your milk.
- If you make dishes in which the eggs are only lightly cooked, such as some sauces, serve the food immediately or refrigerate. Don’t let it stand around at room temperature.
- Any soufflés, egg nogs etc., containing raw eggs must be kept in the refrigerator until just before they are eaten. Avoid giving young children, the elderly and people with impaired immune systems foods containing raw or lightly cooked eggs.
- Observe good personal hygiene when preparing food; always thoroughly wash your hands before starting to prepare food and after handling raw foods.
Egg quality: what to look for when buying
If you look closely at an egg shell held against a bright light in a dark room you will be able to see an air gap, usually at the blunt end of the egg. In a fresh egg this air cell is quite small but as the egg ages, water is lost from the 17 000 pores in the egg and the air cell gets larger. Also you can see a large moving shadow in the egg which is the yolk floating about in the white.
In fresh eggs the yolk is small and in the centre of the egg. If you hard boil an old egg, you can quite clearly see the air cell indentation in the top of the egg, you can also identify if the yolk has moved off centre by cutting a hard-boiled egg lengthways.
Fast Facts:
- A quick test for freshness is to check if the raw egg in the shell sinks in a basin of water. Fresh eggs stay at the bottom of the bowl while stale eggs stand on end or float because of the large air cell.
- Good quality, fresh eggs display certain characteristics when broken out.
- The yolk is small and rounded and stands high in a thick, gel-like egg white which tends to stay compact rather than spread out over a wide area.
- As eggs age, the yolk becomes larger and flatter, until it eventually breaks.
- The thick egg white becomes thin and runny. By this time the egg will also have developed a stale odour and flavour.
Storing eggs: control the temperature
The easiest way to maintain eggs at high quality is to store them in cartons in the refrigerator as soon as possible after they are laid. Clean eggs, free of visible defects of the shell and contents, will then remain at high quality for up to three months and will still be as ‘fresh’ as eggs stored for seven days at room temperature. They can be stored for longer periods but the quality will begin to deteriorate noticeably. The cartons reduce water loss and help prevent flavours from other foods from being absorbed into the eggs.
When storing eggs it is important to only store clean, uncracked eggs. Keep dirty or cracked eggs separate to avoid contamination of the clean eggs, these eggs should also be used immediately or frozen as pulp. Under no circumstances should eggs for in-shell storage be washed as this removes the surface bloom and makes the eggs more susceptible to attack by microbes.
Egg safety: how to enjoy your eggs without getting sick
Eggs are similar to other protein foods such as meat, fish and poultry, in that they may be contaminated with microbes which can, if allowed to grow, cause food poisoning. Although Salmonella is easy to destroy in cooking (any food cooked uniformly to a temperature of 72 °C will be free of Salmonella), poorly handled eggs have caused many documented outbreaks. This is often the result of consuming eggs raw or only lightly cooked.
11th April 2016 at 5:15 pm
I like boiled eggs. I’ll boil 12 new eggs from the supermarket, cool then refrigerate them to have two cold boiled eggs each day for lunch. Why do some of the yolks look grey?
26th April 2016 at 11:54 am
Hi Grant,
You should not be concerned if you see a greenish grey on the surface of the yolks of hard boiled eggs. This is due to a harmless chemical reaction between sulphur from the egg white and iron from the egg yolk resulting in the formation of ferrous sulphide usually at the boundary between egg white and yolk. To minimise this reaction, avoid overcooking eggs and cool boiled eggs quickly by immersing boiled eggs in ice cold water. Refrigerate them as soon as possible once they are cooled.
Regards,
Ellen
CSIRO Social Media
11th April 2016 at 4:41 pm
If you are going to take eggs on a camping trip where you will have no refrigeration, is better to take them raw or boiled? Which will last longer? I have read that you should not store eggs outside the fridge once they have been refrigerated otherwise condensation will form on the eggs which allows bacteria to invade the egg more easily, is this true? .
26th April 2016 at 11:53 am
Hi June,
Raw eggs would be safer to take on a camping trip than boiled eggs, but obviously more susceptible to breaking. Raw eggs by nature are stable at ambient (room) temperature for some days – refrigeration is recommended to improve their safe shelf life. To combat the condensation, allow eggs to come to room temperature and allow any condensation on the eggs to dry before packing for your trip. Once you boil an egg, the natural preservation system in the egg is no longer in place. We hope this helps!
Cheers,
Ellen
CSIRO Social Media
6th April 2016 at 9:59 am
Question about egg washing for people who keep chooks – The article mentions to store only clean uncracked eggs, keep the dirty ones separate and use immediately. (How immediately?) I always wash my dirty eggs under running water, dry with a cloth and store with the rest in an egg carton in the fridge. Will this cause problems? Appreciate the advice. Thank you
11th April 2016 at 9:50 am
Hi Virginia,
If you are planning to use cracked and/or dirty eggs, only use them in foods that are thoroughly cooked; use immediately (on the same day) or refrigerate immediately and use (in cooked foods only) within a few days.
You should also avoid washing eggs regardless of whether they are dirty or clean. The shell provides natural protection for the egg contents and washing eggs can allow the transfer of harmful bacteria from the outside of the egg to the inside.
5th April 2016 at 2:23 pm
Very helpful thanks
5th April 2016 at 2:23 pm
Good advice for Granny to share.