Fresh eggs are essential when used to give lift to cakes or to whip up into meringue to make pavlovas, soufflés or light-as-air Chocolate Mousse. This is because old eggs don’t whip up as well.
Fresh eggs are also better for poaching because they have tighter whites so they poach neatly.
But how can you tell how fresh your egg is before you even crack it? Here’s a quick tip: Simply put the egg in a glass of water and watch how it floats:
Eggs start to degrade in quality the moment they are laid by chickens. This is because egg shells are porous and over time an egg will absorb air.
Therefore older eggs have more air inside than super-fresh eggs, and will be more buoyant when placed in a glass.
When fresh eggs really matters
It’s really important to use fresh eggs when a recipe is relying on whipped eggs for aeration or to make something rise. Here are some examples:
Cakes – not all cakes rely on whipped eggs, but the ones that do yield professional bakery style plush, light as air sponges, such as this Vanilla Cake, Blueberry Layer Cake and Vanilla Cupcakes. For these cakes, fresh eggs is best for maximum cake rise. 1 week old eggs are ok (cake rises marginally less). I do not recommend using eggs 2 weeks+;
Pavlova and Meringue – made of whipped egg whites, so fresh eggs is essential!
Mousse and soufflé – made light as air from whipped egg whites.
Chocolate mousse 
Pavlova 
Vanilla Cupcakes 
Best ever vanilla cake – professional bakery style!
What happens if you use old eggs
If you use older eggs, the cakes will not rise as well and pavlovas will be flatter than they should be. Generally, the cakes will still work as long as you get some volume from beating, they just won’t be as tall or light-as-air as they should be.
During the course of testing the Vanilla Cake recipe, which I made a LOT because it’s such an important master recipe, this was especially noticeable. Using older eggs (2+ weeks old), the cake was still fluffy (because that cake has so much room for error) but the height was 15 – 20% less than the cake made with fresh eggs.
When older eggs does NOT matter as much in baking
Any recipe where egg is just mixed into a batter without beating to make it fluffy and aerated. This is the case with most standard cupcakes and muffins, cakes and cookies.
Of course, make sure it’s not past the expiry date…. then it’s no good in ANYTHING!!!
I know this isn’t an exciting new recipe post, but it’s a lessor known yet essential baking essential tip because it’s a hidden cause for cakes not rising as they should. File it away under useful to know! – Nagi x
Life of Dozer
Fan of eggs in any form! Scrambled, in this case. 🙂
Hiya! Just letting you know your yummy lemon blueberry cake link is broken on this page =D
YUMMY lemon blueberry cake link hahaha (such a delicious picture!)
I used your search feature and found it though at /blueberry-cake-with-lemon-frosting/
(ie. without the “3-layer-” bit in the URL ^-^
Also that’s an AMAZING-ly adorable picture of your dog eating scrambled eggs! its proper cheers me up each time i’ve scrolled passed it today just now ^_^
Hi D – I just clicked the link to check and it worked fine – I think maybe it could be your browser! N x
Hi Nagi,
Reading through your Pavlova recipe, which requires (4)eggs.
Can I substitute egg whites from a carton and how many ml’s should I use?
Hi Kevin – we tested this on the Holiday Pav Tree recipe with carton egg whites and it did not work as well as using eggs, sorry! N x
This tip should go in your book!
It will! 🙂 N x
My Mother never taught me to cook (perhaps she didn’t know how), therefore, I have learned on my own with web sites such as yours. I read everything and watch how it’s done. Thank you for being a teacher no doubt for so many. Appreciated.