Flour

Wheat flour is produced by grinding and sifting wheat grain to a powdered form that can vary in texture from fine to coarse. It is used as one of the main ingredients for a wide range of foods throughout the world, including breads, cakes, pasta, biscuits and pastries, and may also be used for a number of other cooking tasks, such as thickening sauces or coating raw meat or fish before frying.

Flour may be white, brown or wholemeal, depending on how much of the grain is used. White flour is made with only the central part of the grain (about 75% of the entire grain), brown flour is made using about 85% of the grain, whilst the whole wheat grain is used to make wholemeal flour. In the UK, the law requires that the nutrients lost in milling are added to brown and white flour, including calcium, iron, thiamine and niacin.

In addition to the colour, there are a number of different varieties of flour, each designed for a specific type of cooking. Their suitability is dependent on their protein quality and content, and how much gluten is formed when the flour is mixed with liquid. Gluten provides dough with elasticity, which enables it to rise effectively when added to a leavening agent such as yeast. The more protein in the flour, the more gluten is formed. Foods that need to be able to stretch and rise or that require a firm, dense structure (for example, bread or pasta) should be made using flour that produces high levels of gluten, whilst items that require a lighter structure or that do not need to rise (such as cakes or biscuits), should be made with flour that produces low levels of gluten.

The protein content and the quality of the gluten in flour is dependent on the type of wheat used. Wheat varieties sown in the autumn or winter (the most common varieties grown in the UK and northern Europe) produce soft grains with a low protein content. This type of wheat is known as 'soft wheat', which is milled to produce soft (or weak) flour. The gluten formed from this flour is extensible but not very elastic, making it ideal for making biscuits and light sponge cakes. Wheat varieties sown in the spring in hotter climates tend to produce hard grains with a high protein content. Known as 'hard wheat', these grains are milled to produce hard (or strong) flour. The gluten produced from strong flour is elastic but inextensible, making it suitable for making bread, pasta and puff pastry.

Plain flour is usually made from soft or medium flour; it is strong enough to allow cakes and other baked goods to rise, yet weak enough to prevent them from acquiring a tough or dense texture. This makes it a good all-round flour, suitable for most purposes. Self-raising flour is simply plain flour with a leavening agent already added, making it perfect for making light, airy sponge cakes.

In this section, you'll find a guide to the range of different wheat flours available in the UK and abroad, along with advice on how they may be used.