Baking is a hobby that has brought me so much joy. But it always seemed an arcane art.
Sometimes a cake would turn out extraordinarily well. The next time I made the same recipe it would flop. I had rubbery cakes, sunken cakes and cakes with lumpy bits of powder in them.
This once joyful hobby became frustrating. The delicious anticipation of a cake on a Sunday afternoon turned into trepidation every time I opened the oven door.
I reached my lowest point after a string of failed cakes. It was either give up or find a new approach.
Many of the “rules” of baking seemed unfathomable. I’m not a robot. Why was I supposed to follow this mythic lore?
Always sift the dry ingredients.
Bake the cake as soon as you’ve mixed it: don’t wait.
Give the cake tin a sharp tap on the counter before you put it in the oven. Whatever you do, never open the oven door until the cake is nearly done.
But maybe, just maybe there was something in those old rules. I began to wonder if science might be my last chance to save my love of baking.
What are the cake ingredients for?
I decided I’d have to do some research on the science of cake. Science, I should explain, was my professional training. Why not apply a bit of that nous to baking?
What I found is that all the basic ingredients have a combination of roles to play.
Flour is the main structural element, forming stretchy gluten molecules that expand as they heat up and become baked into place. The fat gives a smooth texture to the cake and stops it from being rubbery.
Eggs stick fats and wet ingredients together, as well as trapping air in bubble structures. A raising agent creates even more bubbles by releasing carbon dioxide into the mixture.
Sugar turns out to be far more complicated than I’d guessed. It’s there for sweetness, obviously, but it is also key to holding on to moisture. Furthermore, it is involved in chemical reactions at oven temperature which produce the characteristic tastes of cooked food. Browning occurs through caramelisation of sugar and results in yet more complex flavour molecules.
When cakes go wrong
Ah, now I was getting somewhere. With this knowledge under my belt I could start digging into why my baking was so scrappy.
Slowly but surely I began to understand the rules of the game.
Maybe these things have happened to you, too. Here’s the lowdown on the most common problems I had, how to fix them and why the fixes work.
Firstly, definitely sift. The effort to sift all the dry ingredients together really is worth it. It distributes raising agents more evenly (and cocoa powder or spices, if you’re using them). It also gets rid of annoying clumps.
If you’re folding in the flour by hand, make nice figure of eight movements and don’t forget to get right to the bottom of the bowl. This is so you don’t end up with those pockets of dry flour I used to randomly come across in an otherwise good cake.
If you’re using an electric mixer, stop once or twice to scrape down the sides and bottom with spatula to make sure you’ve gathered the dry ingredients.
Doesn’t rise properly
Gentle figure of eight folding keeps the air in, making your cake is light and fluffy. More vigour will knock the air out and make the cake flatter.
If you’re going down the electric mixer route, make sure you have enough raising agent to re-add bubbles, this time in the form of carbon-dioxide. Beware: I’ve also overdone it with raising agent and the cake had a horrid bitter edge. Finding a balance between rise and flavour is important.
If you’re using a self-raising/self-rising flour or you added raising agents such as baking powder or bicarbonate of soda they will start to work as soon as they hit moisture. The longer you wait, the more bubbles you’ll lose from the cake mixture before baking and risk a poor rise.
So the old saw that you shouldn’t leave your mixture hanging about on the counter is true. No more leaving the mixture on the side while the oven heats up. Preheat and pop it straight in.
Rubbery texture and cake flop
On the other hand, it’s quite easy to batter the batter to death. Especially if you’re using an electric mixer.
Why is this bad? The more you work the mixture, the air is knocked out and more gluten is formed from the flour. You want enough gluten to make a cake structure but not so much that it turns to rubber.
Bizarrely, an overmixed batter will look smoother and more uniform than a well-mixed one. This had me confounded for a long while. It looks so nice!
But a batter with a silky sheen rather than a feathery lightness is not good news.
The upshot is a cake likely to sink when baking. More importantly, the proof being in the proverbial pudding, the texture ends up chewy and may have dense bits.
Pockets and holes
After banging on about getting air in and keeping it in the mixture, this was a bit counterintuitive: too much air can make bits of your cake sink into holes. Yet it’s true.
It’s the little bubbles from careful folding or created by the raising agents that are good. Large air pockets trapped in the batter, however, are not. They form cavities. These heat up, expand and burst before the cake structure is fixed. Bits of your cake sink into the pockets.
Fortunately, this is an easy one to prevent.
I now take a moment to give the pan a couple of sharp taps on the counter before cooking. That’s another piece of baking lore that holds up to science: the tapping breaks the largest trapped air bubbles and releases them before the bake.
A nicely risen cake suddenly sinks
Opening the oven door mid-bake is the classic cake-baking no-no. But why?
Gluten formed from flour and moisture is elastic. It stretches as the batter expands with the air and carbon dioxide bubbles.
At high temperature, that gluten structure loses its elasticity. This fixes the shape of the cake.
Until this fixing process is finished, don’t open the oven!
The temperature will drop and the gases stop expanding. If you leave it too long, they’ll even start to contract.
Your cake will sink.
British chef Delia Smith recommends waiting until at least three quarters of your baking time has elapsed before daring to open the oven door to test the cake. So that’s what I do.
My baking laboratory
I don’t pretend to have a perfect run of baking. I’m still learning. But I have become a much better baker. Most of the time, I can catch myself before I fall into the worst traps.
Having a view on to the science also helps me experiment with new recipes, both for flavour and replacing ingredients — using fruit, natural sugars, baking gluten-free, choosing between butter and oil.
Moreover, when the kitchen became my laboratory and I learned to love baking again. Combining my passion for science with baking turned my frustration on its head. I understand why baking happens the way it does and can tease apart my mistakes.
It’s left me wondering what other things in my life I could revitalize with a dash and dollop of science.