Freshly Baked Science
How to: Make Perfect Meringues (According to Science)
21st December 2018
Meringues are the perfect dessert all year round (check out our Christmas meringues here) and we want to make the best meringue possible. This is where science steps in, with some top tips on making award-winning meringues. We’d also like to discover how on earth substituting egg whites for chickpea water (?!) creates a vegan meringue! But let’s start with regular meringues made with eggs.
Check out our recipe for Christmas meringues here!
Believe it or not, where you store your eggs will actually have an effect on the quality of your meringue. An egg white is made up of 90% water and the rest is nearly all protein, with some vitamins and minerals. When an egg is at room temperature, the protein in the egg white is more moveable, meaning it will whisk up more readily when making meringue. If you store your eggs in the fridge, the protein doesn’t have this head start, meaning it will require more work to whisk them up. Because of this, using room temperature eggs results in fluffier, more airy meringues!
Separating eggs can be an extremely fiddly task and it’s not unknown for the yolk to break and leak a few drops into the white. But that’s ok, right? Wrong. Unlike egg whites, the yolk contains fat, any fat in the mixture can burst the air bubbles you worked so hard for.
For the same reason, try to avoid separating your egg using your hand. As much as we wouldn’t want to admit it, our hands can get pretty greasy. As we know, grease is fat, so this can also play a part in popping those lovely air bubbles!
Choose the bowl wisely
A plastic bowl is by far the worst bowl to use when making meringues. The plastic can retain fats, which brings us back to the previous issue, so try to stick to a glass or metal bowl. If you have one, a copper bowl is the best possible option. The copper ions in the bowl actually react with the egg whites and lead to a fluffier, stiffer meringue!
Use sugar and stabilizers
When you whisk up egg whites, you are disrupting the protein, causing them to take up more space. While this happens, the amino acids that make up the protein become exposed. The hydrophobic amino acids protect the air bubbles, linking with other amino acids to form nets and prevent the bubbles bursting.
Adding sugar when the egg whites have become fluffy and white causes the sugar to cling onto the edges of the air bubbles, making them more stable (and making the meringue sweet and delicious).
Stabilisers, like vinegar and lemon juice, encourage the bonding of other amino acids to each other, making the meringue stronger and less likely to deflate!
Don’t over whisk
You may think that the more you whisk, the fluffier your meringue will be. This isn’t the case as when you over-whisk, too many amino acids join together, creating a super tight net! If the net is too tight, water will be forced out of the meringue and cause the mixture to curdle.
Finally, we move onto how it is possible to switch the egg whites for chickpea water. Chickpea water is simply the water that canned chickpeas float in. This water contains starch, proteins and a foaming agent called saponin.
A saponin molecule is similar to an amino acid, as one side is hydrophilic (loves water) and the other is hydrophobic (hates water). When these cling together, it forms a barrier between air and water, which is what produces those lovely air bubbles.
Luckily, this water is fairly tasteless and doesn’t affect the flavour of the meringue, making it the perfect substitute. So next time you’re cooking dessert for a vegan friend, or you have run out of eggs, why not give it a go?
Do you have any top tips when you make meringues? We’d love to hear from you via email (firstname.lastname@example.org) or social media (@wonkscience) with the hashtag #STEMintoChristmas!