THE INDUSTRIAL BAKING PROCESS
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:
- flour
- yeast (to make the bread rise)
- salt (to add taste and aid proving),
- vinegar (a preservative)
- vegetable fat (to make the loaf lighter and airier and extend its shelf life)
- water.
All white bread sold in the UK is made with white flour which has been fortified with calcium, iron and B vitamins.
Yeast
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 in bread-making 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.
Protein
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.
Industrial baking
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
The 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).
Next
Mixing, dividing and first proving
All the ingredients are mixed at high speed. The process takes 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).
Next
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 above the baking tins. The dough is dropped into the
pre-greased tins.
Next
Second proving
The tins pass along the conveyor belt into a warm area. Here the second
proving stage takes place, lasting around 50 minutes.
Next
Baking
The loaves pass into a huge oven on a conveyor belt. The trays move slowly
through the oven for about 20 minutes. Basic bread doughs are usually baked
at 230°C (450°F, gas mark 8).
Next
Depanning and cooling
The baked loaves come out of the oven into the cooling area. The bread is
sucked out of the tins. The bread is 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.
Environmental policies for the baking industry
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:
- conform to all relevant legislation and codes of practice
- follow good manufacturing practice
- recognise the need to provide customers with safe, wholesome products
- take action to minimise emissions to air, land and water
- make efficient use of energy and take action to reduce consumption
- make efficient use of raw materials and packaging
- seek continuous improvement in environmental performance
- monitor progress towards agreed objectives.
Bread labelling
By law, wrapped bread must be labelled with certain information such as:
- the name of the product and a description of the type of bread, e.g. white, brown, wholemeal
- a list of ingredients
- information on for how long it will stay fresh
- information on how to store the bread
- the weight of the loaf
- the name and address of the producer.
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 either show four nutrients:
- the energy value (in kilojoules and calories)
- the amount of protein, carbohydrate and fat (in grams)
or these four plus:
- sugars, saturated fat, fibre and sodium.
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.
Bread types
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:
- White bread is made from flour that contains only the endosperm of the wheat grain (about 75% of the whole grain).
- Wholemeal bread is made from the whole of the wheat grain with nothing taken away. Wholewheat is another name for wholemeal.
- Brown bread is made from flour from which some bran and wheatgerm is removed (it uses about 85% of the whole grain).
- Soft grain bread is made from white flour with extra grains of softened rye and wheat to increase the fibre content by 30% compared with standard white bread.
- Sandwich loaves can be white or brown bread. They are baked in tins and have a flat top, giving even and rectangular slices.
- A cottage loaf has two round sections, one on top of the other. It is believed to date back to Roman times when it was invented to make the most of the height of the oven.
- There are a huge range of speciality breads available, originating from different cultures, e.g. pitta, naan, chapatti, ciabatta, bagels, soda bread and baguettes.
