Welcome to Your First Bake... of Knowledge
Hello, and welcome! Before we start pulling trays out of the oven, we need to meet three ingredients you'll use in almost every bake: flour, sugar and fat.
You may think of a recipe as a list of instructions. Try thinking of it as a team instead. Each ingredient has a job. Once you know what those jobs are, you'll understand why a recipe works, and you'll be able to work out what went wrong when it doesn't.
Let's start with the ingredient that does most of the heavy lifting.
Flour: The Builder
Flour gives a bake its structure. It's the scaffolding that holds everything up.
How does it do that? Wheat flour contains two proteins called glutenin and gliadin. On their own in the bag, they don't do much. Add water and they hydrate. Then, when you mix or knead, they link up into a stretchy network called gluten.
You can think of gluten as a net of tiny elastic bands. Glutenin gives the dough its springiness, so it snaps back when you pull it. Gliadin lets it stretch. Together they make a dough that can stretch, hold its shape and trap gas, a bit like a balloon.
So here's a question for you. Do we always want lots of gluten?
Nope! It depends entirely on what you're baking.
For bread, you want plenty of gluten. A strong network traps gas and gives you a tall loaf with a chewy crumb. That's why bread dough gets a good long knead.
For cakes, biscuits and pastry, you want much less. Too much gluten makes a cake tough and rubbery and makes pastry shrink in the tin. That's why cake recipes tell you to mix just until combined. Every extra stir builds more gluten.
Choosing Your Flour
The amount of protein in a flour tells you how much gluten it can build. That's what separates the three flours you'll meet most often in the UK.
Strong bread flour is milled from "hard" wheat and has more protein, usually about 12–14%. Use it for loaves, rolls and pizza dough, where you want lots of gluten. In the US it's sold as bread flour.
Plain flour has less protein, usually around 10%, though it varies a little by brand. It's your everyday flour for pastry, biscuits and thickening sauces. Americans call it all-purpose flour.
Self-raising flour is plain flour with a raising agent (baking powder) already mixed in. It's handy for sponges and scones. We'll look properly at raising agents in the next level, so for now just remember that self-raising flour comes with its lift built in.
Let's try one. You're making a crusty white loaf. Which flour do you reach for? Strong bread flour, of course, because you want all that gluten. And for a crumbly shortbread? Plain flour, because you want it tender.
Sugar: Much More Than Sweet
You probably think sugar is just there for sweetness. It does sweeten, but it has a few other jobs too.
First, sugar browns. When it's heated it caramelises, and it also takes part in the Maillard reaction, where sugars react with proteins. Those two reactions give you that golden colour and toasty flavour on top of a cake or the edge of a cookie.
Second, sugar keeps bakes moist. Sugar is hygroscopic, which means it attracts water and holds on to it. That's why a good cake stays soft for days. Brown sugar, which contains some molasses, holds even more moisture, so it tends to give chewier cookies.
Third, sugar makes bakes tender. It gets in the way of gluten forming, which helps give a soft crumb.
So what happens if you cut the sugar in half to make a cake healthier? You lose more than sweetness. You'll likely get a paler cake that's drier, a bit tougher and quicker to go stale. A small reduction is often fine, but a big cut changes the whole bake.
Fat: The Tenderiser
Now for fat: butter, lard, oil and so on. Fat's main job is to make bakes tender.
When fat coats the flour, it gets between those gluten-forming proteins and stops them linking up so easily. In fact, that's where the word "shortening" comes from. Fat literally shortens the gluten strands, so you get a crumbly, melt-in-the-mouth texture.
Fat can also make things flaky. When cold little pieces of fat are left in a dough and rolled out, they form thin layers. In the oven they melt and leave flaky gaps behind. Keep that idea in mind, because it'll come back when we get to pastry.
And of course, fat carries flavour. Butter tastes wonderful!
Swapping Fats: What Changes?
Can you swap butter for something else? Sometimes, but expect some changes.
Butter is roughly 80% fat, with most of the rest being water. Block margarine with a similar fat content often swaps in fairly well. Low-fat spreads are a different story. They contain much more water and less fat, so bakes come out drier, tougher and paler, and biscuits can spread or turn soggy. Check the label: if it's called a "spread", be careful about baking with it.
Oil is liquid, so it can't hold air when beaten the way soft butter can. It makes a lovely moist cake in recipes written for oil, but swapping it straight into a butter recipe can give you a denser result. You'll also lose that buttery flavour.
You've Got This
See how it all fits together? Flour builds, sugar sweetens, browns and keeps things moist, and fat tenderises. Once you understand those jobs, a recipe stops being a list of magic steps and starts to make sense.
Key takeaways
- Gluten forms when flour's proteins (glutenin and gliadin) meet water and are mixed or kneaded.
- You want lots of gluten for bread and as little as you can get away with for cakes, biscuits and pastry.
- Strong bread flour (about 12–14% protein) is for bread, plain flour is for pastry and biscuits, and self-raising flour is plain flour with raising agent added.
- Sugar sweetens, browns, keeps bakes moist and makes them tender, so cutting it a lot changes more than the taste.
- Fat makes bakes tender and, when left in cold pieces, flaky. Low-fat spreads contain more water and don't bake like butter.