What Is Cake Flour

Cake flour emerged in the early twentieth century as bakers sought a finer, more delicate crumb in their cakes. While traditional all purpose flour contains a range of wheat protein levels to suit breads and pastries alike, cake flour is milled from soft wheat varieties that naturally yield lower protein. The result is a pale, velvety powder that, when combined with other ingredients, produces cakes renowned for their lightness and tenderness. In Britain cake flour remains less common in home kitchens than on the other side of the Atlantic but its unique properties have earned it a loyal following among pastry chefs and keen bakers looking to elevate their sponge cakes, cupcakes and chiffons.

Composition and Protein Content
The defining feature of cake flour lies in its protein content. Most cake flours contain between seven and nine per cent protein, compared with around ten to twelve per cent in plain flour or all purpose flour. Protein in flour develops into gluten when mixed with liquid and agitated. While a strong gluten network is desirable in bread to provide structure and chew, in cakes it can lead to a tough, rubbery texture. The lower protein of cake flour limits gluten formation, allowing bakes to rise with grace and maintain a tender, fine crumb. Cake flour is also milled more finely than other flours, which increases its ability to absorb liquid and sugar uniformly, resulting in an evenly smooth batter.

Bleaching and Functional Benefits
Many commercial cake flours are treated with bleaching agents such as chlorine. This process not only whitens the flour but also alters its starch and protein behaviour. Chlorination makes starches more capable of retaining moisture and slows gluten development even further. The combination of fine milling and bleaching ensures that cake batters achieve maximum volume and stability, while also producing a whiter crumb. Home bakers who prefer to avoid chemically bleached ingredients can find unbleached cake flour alternatives or create their own by blending plain flour with a small amount of cornflour and sifting thoroughly to lighten the texture.

Substituting Cake Flour in Recipes
When a recipe calls for cake flour but only plain flour is available, a simple substitution can be made. For every one hundred grams of cake flour required, measure out ninety-five grams of plain flour then remove five grams and replace it with five grams of cornflour. Sift the blend at least twice to ensure an even distribution of starch and to introduce air that mimics the texture of cake flour. This homemade version approximates the lower protein and fine grain of commercial cake flour sufficiently for most home baking needs.

Applications in the Kitchen
Cake flour shines in preparations where a delicate crumb is paramount. Sponge cakes rely on the gentle structure provided by cake flour to trap air bubbles created during creaming and whisking, leading to lofty, tender layers. Chiffon cakes and angel food sponges, which depend on whipped egg whites for lift, also benefit from the subtle support of cake flour without the risk of overdeveloped gluten. For cupcakes and petite gâteau, using cake flour ensures each bite remains light rather than dense. Beyond sweet bakes, some pastry chefs use cake flour in pastries such as choux buns or soft biscuits where a tender mouthfeel is desired.

Variations and Speciality Flours
Speciality cake flours have entered the market to cater to diverse dietary needs and flavour preferences. Gluten free cake flours blend rice flour, potato starch, tapioca starch and xanthan gum to recreate the binding and structural properties of wheat cake flour. Whole grain cake flours, produced from soft white wheat berries, retain more of the wheat germ and bran for added nutrition while still offering a relatively low protein profile. Flavoured cake flours infused with matcha powder, beetroot powder or cocoa exist for creative bakers, although these require recipe adjustments to account for additional dry ingredients and colour.

Health and Nutritional Considerations
Cake flour’s low protein and fine texture make it ideal for light baked goods, but it offers fewer nutrients than wholemeal or high protein flours. It contains less fibre and fewer vitamins and minerals retained in the bran and germ layers of the grain. When using cake flour in larger quantities, as in layer cakes and celebration bakes, it is wise to balance the meal with whole grains and fresh fruit to ensure a wholesome diet. For those monitoring their gluten intake, certified gluten free cake flour blends provide a safe alternative without sacrificing the delicate structure prized in cakes.

Shopping and Sourcing in the UK
Cake flour may not be a staple on every supermarket shelf in the UK, but it can be found in larger branches of well known retailers, in speciality baking shops and online. Look for respected brands that specify protein content and milling processes on their packaging. If bleaching is a concern, seek unbleached or naturally white cake flours, sometimes labelled as ‘white cake flour’ without chemical bleaching. Bakeries and cookery schools often stock cake flour for their classrooms, and local independent delis or baking supply stores can order specific brands on request. When storing cake flour at home, keep it in an airtight container in a cool, dry place away from strong odours to maintain its freshness and moisture content.

Expert Tips for Optimal Results
For the lightest cakes, always measure cake flour by weight rather than volume; a kitchen scale eliminates the variability of scooping and tapping. Sift cake flour at least once before incorporating it into the batter to break up any lumps and to add air. When folding flour into whipped egg mixtures or creamed batters, use a gentle motion to preserve air bubbles. Over mixing at this stage can deflate the batter and lead to a denser texture. Preheat the oven fully before baking; cake flour batters are sensitive to temperature and a sudden drop can affect rise. Finally, cool cakes on a wire rack to allow steam to escape evenly, preventing soggy tops or collapsing centres.

Common Pitfalls and How to Avoid Them
A common mistake is using cake flour in recipes that call for plain flour, such as cookies or bread, which can result in a product that is too soft and lacks structure. Always match flour type to the intended texture of the bake. Another error is ignoring the unique hydration properties of cake flour; it often requires slightly more liquid or egg than plain flour to achieve the correct batter consistency. Pay attention to batter thickness and be prepared to adjust by adding a splash of milk or an extra yolk. Finally, many home bakers unknowingly pack cake flour into measuring cups, leading to over measurement; scooping lightly and levelling off the top ensures accurate quantities.

Conclusion
Cake flour represents a specialised tool in the baker’s repertoire, engineered to produce confections with exceptional tenderness, fine crumb and brilliant height. Its low protein content and fine milling create the ideal canvas for sponges, chiffons and cupcakes that delight with each airy bite. While not always readily available on every shelf, cake flour can be sourced or simulated at home to elevate baked goods from ordinary to outstanding. By understanding its unique properties, applying careful techniques and choosing the correct flour for each recipe, home bakers can achieve professional quality results and savour the light, delicate textures that define classic cakes.