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How Beer is Made

Ingredients


The water must be pure, with no trace of bacteria. This is vital, because it allows the other ingredients to release all their flavour. 95% of breweries have their own spring or natural well. In Wallonia, the water has specific regional characteristics: calcareous in Hainaut, more ferruginous in the Ardennes.
Barley is a cereal that offers a key advantage: it can be preserved for a long time after harvesting. In order for barley to be used in the making of beer, it must first be malted. It is malted barley that gives beer its characteristic colour and taste.
A number of other cereals are used in the brewing of certain types of beer: oats, corn and wheat.
Hops or "green gold" come from a climbing plant with male and female flowers; only the female flowers are used. There are various varieties, ranging from very bitter to aromatic. Hops grew naturally in our regions in ancient times, and this plant has been used by brewers since time immemorial. It could be replaced by mixtures of aromatic herbs, in particular rosemary and thyme, which had the same preserving effect as hops but of course gave the resulting beverage a quite different flavour. Yes, it is hops that give beer its characteristic bitterness, and this plant became so successful that in the 18th century all varieties of beer contained hops.
Yeasts transform the sugars in the must into alcohol and carbon dioxide. The type of yeast used varies according to the type of beer. There was a time when man had no control over yeasts in beer. Louis Pasteur was able to explain their role in the brewing process, and yeast culture was developed thanks to the work of the Danish scientist Hansen. Nowadays there are two main varieties of yeasts that are used in brewing: saccharomyces cerevisiae and saccharomyces carlsbergensis (bottom-fermenting).
Certain other products are used in the making of beer, in particular spices: coriander, ginger, cloves, sage, fennel, mustard seeds, aniseed, cinnamon, etc.

The production process


Malting: the conversion of barley grain into malt
The purpose of this process is to encourage the barley grains to germinate so that they can be used in the making of beer. This involves immersing the grains in water then leaving them to germinate for about five days before arresting the germination process using hot air to dry them at around 65°C (kilning). This interruption is necessary to retain some sugar for the brewing process. The malts will develop a different flavour and colour depending on the duration and temperature of kilning. These differences will be reflected in the qualities of the different beers. Germination causes the secretion of enzymes which, when the malt is dissolved in water, will convert the starch into sugars and the proteins into amino acids.

Brewing: the production of must
The malt grains are first crushed (grinding) so that they will dissolve readily in water. Hot water is then added to this grinding process (35-50°C). The temperature of the water is gradually increased to 75°C. At this temperature, the enzymes start to work and convert the starches into sugars and the proteins into amino acids (which, of course, are essential for the yeast). This mixture produces a very hot sweet tea-like juice. It is then naturally filtered (the first filtration) through the husks of the crushed barley grains at the bottom of the vat. This produces a liquid, the "must". The dry residue, which is referred to as the "draff", is generally used as cattle feed. Hot water is usually added two or three times, then the mixture is filtered to extract as much sugar as possible. The filtered must is then transferred to boiling vats, where the hops are added (110 to 300 grams/hectolitre). Sugar can be added at this stage. Depending on the type and quantity of sugar, a hundred different varieties of beer can be obtained. The heating process sterilises the must by killing off the enzymes. The must is then cooled to allow the yeast to germinate.

Fermentation: the addition of yeast
Fermentation is achieved by adding yeast to the cooled must. This converts the sugar into alcohol and carbon dioxide. This process is what mainly determines the taste of the beer. Belgium is the only country that uses three main types of fermentation, according to the type of yeast and the fermentation temperature:
Bottom fermentation produces beer of the Pils type (from the Czech city of Pilzen). The process takes between 6 and 10 days. It is called bottom fermenting because at the end of the fermentation process the yeasts settle at the bottom of the vat. This process involves the use of active yeasts of the saccharomyces carlsbergensis type between 8 and 10°C.
Top fermenting, or traditional fermenting, takes no more than 5 days and is carried out with yeasts of the S. cerevisiae type, which are active between 15 and 25°C. It is called top fermenting because the yeasts work on the surface of the must and forms a thick, foamy layer.
Spontaneous fermentation (used to produce Lambic and Gueuze) is specific to the Brussels area. It involves around a hundred microorganisms (yeasts, bacteria, etc.) which are characteristic of the atmosphere of the valley of the river Senne. After boiling, the lukewarm mixture is pumped into open vats in the brewery loft. It is left there all night to cool and to allow the wild yeasts and bacteria to germinate the must. No more yeast is added by the brewer. The product obtained is called Lambic.

The final stage: the personal touch
Many brewers add different substances to give their beer a characteristic flavour. However, the composition of these substances is one of the many aspects of brewing that are protected by trade secrecy. However, we do know that they can include real fruit, fruit syrup, spices, different types of sugars, honey, etc.
Once the must has fermented, the beer still has to mature. Depending on the type of beer, this maturation or secondary fermentation process can last anywhere between one week and several months (and even 3 years for Cantillon Gueuze). The aim of this process is give the beer time to mature and to clear by letting the yeast settle, to saturate it with carbon dioxide and to give it more flavour. The beer is then filtered, except in the case of beers that undergo secondary fermentation in the bottle, as is the case with Trappist beers, to allow the flavour to continue to mature.


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