Bread has been baked for hundreds of years, and the same basic process is still used by the baking industry today. The main ingredients are:
All white bread sold in the UK is made with flour which has been fortified with calcium, iron and B vitamins. Fortification of brown and white flour is a legal requirement.
Almost all breads today are leavened, which means that a substance has been added to the dough to start fermentation and make it rise. The most popular and widely known leavening ingredient is yeast.
Yeast is a micro-organism, one of the tiniest forms of life. The air around us is full of thousands of different kinds of yeast. If it is given warm, damp surroundings and starchy or sweet matter, it will start to breed. As the yeast multiplies, it turns starches and sugars to alcohol and produces carbon dioxide gas. It is this gas that adds the air into the dough, and makes it increase in size.
The yeast used by bakers is called Saccharymosa cereviserae. It was originally a by-product of brewing beer (when the yeast was used for the alcohol, rather than the carbon dioxide, it produced). Today it is cultivated commercially in laboratory conditions, and sold as fresh, compressed or dried yeast.
Yeast must be mixed with a warm liquid before adding it to flour. If the liquid is too cool, the yeast won't multiply; if it is too hot (over 43°C), the yeast will be killed.
The important protein found in flour is gluten. Gluten gives the dough softness, so that it can expand when the gas bubbles produced by the yeast form. It also gives the dough strength so that the gas bubbles do not burst.
The flowchart shows the processes used in an industrial bakery. If you baked bread at home, you would use similar principles but on a smaller scale.
Delivery and storage
Flour is delivered daily to the bakeries. The bakery also needs stores of salt (to add taste and aid proving), vinegar (a preservative), yeast (to make the bread rise) and vegetable fat (to make the loaf lighter and airier and extend its shelf life).
Mixing, dividing and first proving
The ingredients are mixed at high speed, in under 5 minutes. The dough mixture is removed and divided into individual pieces by machine. It passes along a conveyor belt and is left to 'prove' (when the yeast fills the dough with gas, causing it to rise and aerate).
Kneading and preparation
The dough is continuously kneaded for about two minutes, as it circles through a spiral-shaped machine. The kneaded dough passes along a conveyor belt until it is dropped into pre-greased baking tins.
The tins pass along the conveyor belt into a warm area. Here the second proving stage takes place, lasting around 50 minutes.
The loaves pass on a conveyor belt slowly through a huge oven for about 20 minutes. Basic bread doughs are usually baked at 230°C (450°F, gas mark 8).
Depanning and cooling
The baked loaves come out of the oven into the cooling area. The bread is sucked out of the tins and left to cool for up to 1½ hours. Once cooled, it passes down the conveyor belt to be sliced (if needed) and bagged.
ICT is an important part of the process. Large bakeries use PLC (Programme Logic Controllers) to control a number of the steps during baking. For example, the press of a button can regulate the amount and type of flour to be used, the temperature of ovens and the cooling times.
Large bakeries are committed to maintaining and promoting safe and environmentally responsible practices for the benefit of consumers, the communities in which they operate and their employees. The Federation of Bakers recommends that companies implement strategies to ensure they and their employees:
By law, wrapped bread must be labelled with:
Nutritional content is not essential but, if it is included, it has to follow a strict format. Nutrition information must be given per 100g and may also be given per serving. It will show:
Some supermarkets and manufacturers also use voluntary 'traffic light' labelling on the front of their packets. The traffic light colours show whether the food has high, medium or low amounts of fat, saturated fat, sugars and salt per 100g. Red indicates high levels, amber medium and green low levels.
Source: Food Standards Agency
There are three basic types of flour – white, brown and wholemeal – and bread made from it is usually described using the same terms. Bread is available in a whole range of shapes and sizes, crusty or soft crusted, wrapped or unwrapped, sliced or unsliced. Here are just a few examples: