The brewing process

DOSSIERS
Brewing beer toan 18th-century recipe  Objectives
The brewing process
Science happening in Bokrijk
Science is not always dry as dust
The “Paenhuys van Diepenbeek”
Scientific analysis of a historic brewing process (dating from 1750)
Sources

How things were in a ‘small’ home brewery remains a mystery to many. What we do know, however, is that the brewing process involved hard manual labour. Brewing was a genuine craft, passed down by tradition.

So brewing beer the old-fashioned way is hardly child’s play. For example, the different tanks (capacity 3 000 litres) take a minimum volume of 1 500 litres. This is shovelled over, stirred, filtered and pumped by hand. Then they set to work with mash-staffs weighing several kilos each. Perhaps this “hard labour” is the reason why the experiment was not attempted earlier. A team of 17 was finally recruited for the job in Bokrijk.

To keep a close track of the various stages of the brewing process, the brewery hands from Antwerp University spent the night in the historic village. After all, the process would take a good 72 hours start to finish. The complete process was carried out step by step: from malting and filtering through to hopping. Visitors could observe the brewing activities. So researchers from Antwerp University and ‘anorak’ home brewers could watch over the historic brewing process by day and by night.

The timetable below sets out the different phases of the brewing process. The most aromatic moment is the addition of the hops, around 16:00 hrs.

After much sweat and hard work, a fermentation is finally started in the “kuip”. A frothy layer of top yeast forms on the young beer. The beer now contains a variety of micro-organisms, each gracing the beer with its own particular taste and scent.
1 000 litres of beer will be run off into wooden barrels, 300 litres will be sent for analysis to Antwerp University. The beer will be tested in the university laboratory after a succession of fermenting and maturing periods.

 

Timetable

That craft brewing is “no small beer” is illustrated by the following brewing moments:

4 May

07.00h: Fill and fire wort boiler to 80°C 09.00h: Prepare mash of crushed malt flour and lukewarm water.
Malt flour = grain (usually barley) steeped in water, left to germinate in the cellar, then allowed to dry out in the loft. 12.00h: Run sweetened mash from mash tun to filter vat. 13.00h: Filter mash and transfer wort extract to brewing copper. 15.00h: Boil wort to obtain a sterile liquid. 16.00h: Add hops, keep wort mixture on the boil for 6 hours. Hops give beer its typical bitter taste and improve its storage life and clarity. 22.00h Second hopping for that nice ‘beery’ flavour.
Extinguish fire, allow hopped wort mixture to cool in copper. 24.00h Pump wort over to cooling tank.

5 May

10.00h: Filter wort mixture.
Add yeast.
Allow wort to ferment 48 to 72 hours; clarify beer.

Finishing, 6, 7 and 8 May

  • Flocculation (formation of a thick layer of foam on the wort).
  • The sinks after approximately 72 hours.
  • The beer is run off into barrels and allowed to mature.

 

 

Beer culture

DOSSIERS
History of beer  Beer culture
The history of beer

The etymology of beer is uncertain. Two words are associated with it: bibere and cervisia. Bibere is Latin and means to drink. The explanation would seems simple, but until now it has been the only probable one. Cervisia strongly resembles cerveza, the Spanish word for beer. Cervisia is apparently derived from Ceres, the Roman goddess of agriculture. Beer is considered to be agricultural product in this context.

That Belgium is a country with a definite beer culture is clearly reflected in its language and sayings. They can “bring life to the brewery (liven things up), “fight against the beer quay (fight a losing battle) or something might be “no small beer. Bad tempered “little girls can sometimes be called “a barrel of sour beer and it can be said of headstrong, noisy boys that “young beer still has to ferment.

Sensible beer drinking is healthy

One 25 cl glass of beer is better than none. Two are even better, but more than three is ill advised.
Beer is not unhealthy. On the contrary, if drunk moderately it acts against the occurrence of heart and circulatory diseases, possibly plays a protective role against some forms of cancer, and reduces the general level of mortality. This has been shown by various scientific studies, the main ones of which you will find in this document.
That sensible beer drinking is also good for the soul does not need any scientific confirmation.

Beer also provides a number of important nutrients, including carbohydrates, amino acids, minerals and vitamins. It is not without reason that beer is called liquid bread. Beer does not make you fat either: 1 litre of lager contains fewer calories than the same quantity of wine or soft drink.

Alcohol is a stimulant

Together with coffee, alcohol (including beer) is one of the most used stimulants in the world. Alcohol puts the drinker in a positive mood and helps him or her to relax mentally. The danger of drinking ever increasing amounts can constitute a real problem for some people, however. When the drinker notices that he or she will use alcohol in order to get intoxicated or to forget about problems, then he or she is clearly going down the wrong path. The same also applies to excessive eating.
It can be assumed that certain people run a greater risk of developing in the direction of alcoholism. People with serious psychosocial problems belong to the risk groups, as they cannot resist the group pressure to drink more, and there are also people who have a certain hereditary predisposition towards drinking.
It goes without saying that alcohol can only have a positive influence on general wellbeing when consumed sensibly in moderation.

 

Properties of the hop plant

DOSSIERS
The hop in the brewing process and as medicinal plant  Properties of the hop plant
The virtues of lupulin powder
Medicinal properties of the hop
author and sources

The hop (Humulus lupulus L.) is a dioecious plant of the family Cannab(in)aceae, to which hemp (Cannabis sativa L.) also belongs. Only the hop cones of the female hop plant are used as essential raw material for beer. Female hop cones contain lupulin powder, rich in compounds that give beer a bitter taste whilst also acting as natural preservatives.

The hop is a sensitive plant and does not flourish everywhere. Hops have particular requirements regarding intensity and wavelength distribution of sunlight, and commercial hop cultivation is limited to areas between the 35th and the 55th parallels. The main hop-growing regions in the world are Hallertau (Bavaria), Yakima (Washington), Kent (UK) and Bohemia (Czech Republic) in the Northern Hemisphere and Australia and New Zealand in the Southern Hemisphere. In total, approximately 80 000 tons of hops are harvested from some 135 850 acres. There are about 40 different varieties (cultivars) of Humulus lupulus from which the brewer can choose, according to the style of beer he wishes to brew.

A hop plant has 12 to 20 years of productive life. The above-ground parts of the plant die back during the Winter, but the root stocks survive. In good conditions, a root stock can grow about four and a half feet high and six feet wide. By early Spring, shoots appear on the root stocks. The young hop shoots are a culinary delight! In commercially grown hop plants, shoots are wound around wires in clockwise direction only, and are further secured to an elaborate network of posts and poles to train the upwards growth of the plant. A hop plant can reach a final height of 24, 25 feet.

Hop cultivation in the Northern Hemisphere is situated mainly between April and July. In favourable conditions hop vines can grow by as much as 35 inches a day. A hop plant can attain an average growth rate of 4 inches a day, making the hop one of the fastest-growing plants in the vegetable kingdom. Commercial hop plantations are frequently treated against fungi (mildew, white rot) and pests (lice, red mites). At present – unfortunately – there are no hop varieties that are resistant to predators.

Once the hop plant is fully grown (late June, early July), it begins to flower. After about a month the female flowers develop into the hop “cones”, while the male flowers simply wither away. It is legally forbidden to grow male and female hop plants together in the same field, because fertilized hops are of inferior brewing quality. The presence of fats and oils in the seeds prevents flocculation, and the beer cannot keep its froth.

Ripe hop cones are harvested in late August, early September. The hop cones used to be picked by hand, but now this is done by machines. The machine cuts the vines in the hop field and the hop cones are immediately separated from the vines and leaves in the hop house. The cones are then carefully dried with hot air blowers at moderate temperatures (below 65°C). After all, the moisture content of fresh hops, which can be 75% to 80%, has to be immediately reduced to under 12%, otherwise the hop would quickly become mouldy and spoil. Finally, the dried hops are packed and stocked in bales, preferably at low temperature.

 

Old beer is not harmful to health

DOSSIERS
Beer and its shelf life  Old beer is not harmful to health
The ageing process in beers
High quality water
Lifetime of the head

Old beer is not harmful to health. The EU requirement to place a consume-by date on the bottles was introduced a couple of years ago.
The Objective Beer Tasters, a Belgian association of beer consumers, conducted a campaign against this measure in the past. The breweries are not happy with a compulsory consume-by date on the label, either. Beer does not really go off, although the flavour can change and it may turn slightly cloudy.

Lager in particular has a tendency to cloud over time. The gradual clouding is caused by bonds being formed between proteins (from the malt) and polyphenols (from the chaff of the malt and the hops), so that is why types of malt are selected with not too high a protein content in which the proteins easily coagulate and can be removed during the brewing process. Consumers do not like cloudy lager. Keeping lager clear is generally a sales issue. Drinking cloudy lager has no effect on the health of the drinker. Some special beers are deliberately made and sold cloudy.

 

Protective or carcinogenic?

DOSSIERS
Alcohol and cancer  Protective or carcinogenic?
Alcohol increases the risk of cancer
Beer reduces the risk of cancer
Alcohol and breast cancer

The final word is yet to be said on the influence of alcohol – and beer in particular – on the occurrence of cancer. For a number of cancers, the risks possibly does increase with moderate drinking. More research is needed to clarify matters here.
On the other hand beer contains phyto-oestrogens that have a protective effect against certain cancers. But here again it is too early to pass judgement.
Up until now most information has been collected on breast cancer, where there is a slightly increased risk for moderate to heavy drinkers.

There is a close link between our eating habits and the occurrence of chronic diseases, including cancer. Thus there is a relationship between diet rich in saturated fats and cancer of the breast, intestine, prostate, ovaries and uterus. However, recent cohort studies have shown that the group with high fat consumption barely differs from low fat consumers with regard to the risk of breast cancer.
A fibre-rich diet on the other hand reduces the risk of certain cancers. The influence of alcohol, and beer in particular, on the occurrence of cancer has not been widely researched up until now. Certain trends can indeed be noted. Some studies point to a high alcohol consumption mainly increasing the risk of gastrointestinal tract cancers.
More recent research into other components (ie. not alcohol), including the phyto-oestrogens in beer, point in the direction of a protective effect.

 

Introduction: A shot of alcohol on an empty stomach

DOSSIERS
Hangover cures and science  Introduction
Water
Sport drinks
Amino acid
A shot of alcohol on an empty stomach
Conclusion

Source: New Scientist

The hangover: anyone who hasn’t woken up with workmen in his head deserves to be beatified! Excruciating: a near-death experience, that birdcage mouth, blinding headache, aching hard-rubber joints. Sick, having a groan down the white telephone, calling your friends Hughie and Ethel. Ever since the dawn of time, Homo sapiens has been mortified by the “the morning after the night before”, after all the oh-be-joyful.

Science can do all kinds of things: we can fly to the moon, we make computers with incredible capacities, but just what can’t we do? Apparently, we can’t come up with a scientifically sound, experimentally tried and tested remedy against the hangover. The reason is obvious: the fear of the authorities, doctors and captains of industry that an experimental hangover cure would lead to a catastrophic upsurge in alcohol abuse among moderate drinkers. After all, the hangover is nothing more than nature’s gentle way of reminding you that there really are better in which you might consider treating your body. And thus it follows that there is no scientifically sure way of devising a product against the hangover. To be sure, there is plenty of research afoot on the effect of alcohol on the body. And this is precisely what has incited many researchers to speculate about the best remedies against hangovers.

One modest attempt has in fact been made to study the effect of some folk remedies by empirical scientific experiment. The New Scientist magazine shanghaied a dozen inexperienced volunteers (in the celebrations for the new millennium, which was safely expected to be more than commonly well lubricated). Their task would be to drink prodigious amounts of alcohol and to try out a different pick-me-up each week. The morning after the drinking bout they would record their “grottiness” quotient by reference to a number of symptoms. Mindful of dehydration, the best-known effect of immoderate drinking, the volunteers always drank a glass of water before hitting the hay.

Sport drinks

DOSSIERS
Hangover cures and science  Introduction
 Water
 Sport drinks
 Amino acid
 A shot of alcohol on an empty stomach
 Conclusion

Source: New Scientist

Trotting back and forth to the toilet means loss, not only of water, but also of large amounts of essential ions that are critical important for the metabolism. Sodium and potassium ions, for example, are important for the functions of muscles and nerves. Disturbances of the chemical balance as a result of a lack of such ions may explain symptoms such as headache, vomiting and fatigue.

Alcohol has a number of other nasty tricks up the sleeve: it can affect our sugar reserves and trigger hypoglycemia. Alcohol converts energy-rich glycogen in the liver to glucose, which swiftly exits the body via the urine. Hapless tipplers know only too well the feeling of weakness and grogginess the next day. The question of the ion balance makes some alcohol pundits suspect that drinking ‘sport drinks’ before retiring to bed may spare these unpleasant symptoms: they do after all contain considerable doses of ions and sugars. Hence remedy number two: a can of the stuff. A couple of volunteer drinkers said they felt well the next day, but the sport drinks had only a marginal effect compared with “just water”. A number of volunteers complained of a bloated feeling, not exactly what you might want on a belly full of beer or wine.

 

Amino acid

DOSSIERS
Hangover cures and science  Introduction
 Water
 Sport drinks
 Amino acid
 A shot of alcohol on an empty stomach
 Conclusion

Source: New Scientist Amino acid

Trotting back and forth to the toilet means loss, not only of water, but also of large amounts of essential ions that are critical important for the metabolism. Sodium and potassium ions, for example, are important for the functions of muscles and nerves. Disturbances of the chemical balance as a result of a lack of such ions may explain symptoms such as headache, vomiting and fatigue.

Alcohol has a number of other nasty tricks up the sleeve: it can affect our sugar reserves and trigger hypoglycemia. Alcohol converts energy-rich glycogen in the liver to glucose, which swiftly exits the body via the urine. Hapless tipplers know only too well the feeling of weakness and grogginess the next day. The question of the ion balance makes some alcohol pundits suspect that drinking ‘sport drinks’ before retiring to bed may spare these unpleasant symptoms: they do after all contain considerable doses of ions and sugars. Hence remedy number two: a can of the stuff. A couple of volunteer drinkers said they felt well the next day, but the sport drinks had only a marginal effect compared with “just water”. A number of volunteers complained of a bloated feeling, not exactly what you might want on a belly full of beer or wine.

 

 A shot of alcohol on an empty stomach

DOSSIERS
Hangover cures and science  Introduction
Water
Sport drinks
Amino acid
Conclusion

Source: New Scientist Conclusion

To recap: a magic potion against the hangover does not yet exist. Different people react in such very different ways, so there are surely many factors that influence individual behaviour. In eager expectation of the panacea, we’ll just have to muddle along with the traditional cures: water before bedtime, a bit of sugar, food packed with cysteine. An aspirin or the like will ease the throbbing, but watch out with the painkiller paracetamol! This will only aggravate the harmful effect of alcohol on the liver. And for those who fancy their chances with ‘sport drinks’, NAC and, when push comes to shove, a shot of vodka: effect is not guaranteed, but any old port in a storm.

The best way of not ending up with a hangover was, is and forever shall be: nice and easy does it!

Simply drinking water was the first remedy. Ethanol is hydrophobic, which means that you lose more water than you take in when you drink alcohol. It affects the pituitary gland in the brain. It also stops the production of vasopressin, the antidiuretic hormone that causes the kidneys to absorb water instead of sending it on to the bladder. Once the hormonal key is unlocked, the normal trickle of urine becomes a flood, resulting in dehydration. Now the body still needs water, so it fetches that water from elsewhere in the body, including the brain. The brain shrinks temporarily. The brain itself is insensitive to pain, but researchers are forming the opinion that the dura mater, i.e., the tough fibrous membrane enveloping the brain, shrinks. And this same reshaping touches the pain-sensitive filaments connecting the cerebral membranes with the cranium. Water-loss can therefore cause pain in other parts of the body.

However, the volunteers found that drinking water alone did not help all that much, except for the dry mouth. And that was all.

Obesity, a major health problem

DOSSIERS
Beer and body weight  Obesity, a major health problem
Epidemic
Is there such a thing as a beer belly?
The relationship between beer and obesity: a Belgian survey

Excessive consumption of soft drinks and fruit juice is an important cause of being overweight, especially in children. Traditional table beers are a good alternative, which are not only low in alcohol but also low in calories and do not interfere with metabolism.

Obesity is currently one of the biggest problems in the western world. In order to a tackle this problem it is absolutely essential to teach healthy eating habits, preferably as early as possible in childhood. Children and adolescents who have to contend with obesity often face problems in later life.

When is a person too fat ?

The ideal weight is not a question of fashion but one of medical science. Going by the criterion of health, the ideal weight would be the one that statistically yields the greatest life expectancy as a result of an optimum state of health and a limited risk of disease. It can be calculated whether a person is of a normal healthy weight, too light, or too heavy using the “Body Mass Index” formula.

BMI = weight (in kg) divided by height² (in metres) Classification BMI kg/m²) Underweight < 18,5 Normal weight 18,5 – 24,9 Overweight 25,0 – 29,9 Moderately obese 30,0 – 34,9 Seriously obese 35,0 -39,9 Very seriously obese > 40

Example of someone who weighs 81 kg and is 1.83 m high:
BMI = 81 / 1.83² = 81 / 3.34 = 24.25

 

This table applies to adults. For children the age, height and sex has to be considered. Growth curves are used in order to determine whether a child is too fat. Weight and length in relation to age are shown on these growth curves as percentile lines, abbreviated to P. A weight above P97 or below P3 is considered abnormal.