Beer Production - Biology Notes Online

Health Benefits of Beer

Beer provides numerous health benefits when drank in moderation. Among these fascinating health advantages are the following:

1. Anti-cancer properties

The flavonoid component Xanthohumol in beer hops plays a significant role in the chemoprevention of cancer, particularly prostate cancer.

2. Reduced risk of cardiovascular diseases

Beer contains vitamin B6, which protects against cardiovascular disease by preventing the accumulation of homocysteine.

Beer consumption in moderation increases bone density, reducing the risk of fractures and osteoporosis.

3. Diabetes

With moderate beer drinking, the prevalence of type 2 diabetes would be reduced.

4. Prevention of anemia

Beer is rich in vitamin B12 and folic acid, which help prevent anaemia. Vitamin B12 is also vital for sustaining healthy growth, memory, and focus.

5. Hypertension

According to Biomedicine, beer drinkers have lower blood pressure than those who consume comparable amounts of wine or other spirits.

6. Anti-aging properties

Vitamin E, a significant antioxidant in the body, is made more potent and effective by consuming beer.
It is an essential component of maintaining healthy skin and reducing the ageing process.

7. Gallstones

Regular moderate beer drinking affects cholesterol levels and reduces bile concentration, hence reducing the chance of developing gallstones.

8. Prevention of dementia and coronary disease

Additionally, beer drinking increases the level of “good cholesterol” by 10-20%, hence decreasing the risk of dementia and cardiovascular disease.

9. Aids digestive system

Beer has many digestive qualities, including the activation of gastrin, gastric acid, cholecystokinin, and pancreatic enzymes.

10. Kidney stones and osteoporosis

Beer’s potassium, salt, and magnesium are crucial for lowering the danger of kidney stones.
Beer’s silicon content is rapidly absorbed by the body, which further explains its osteoporosis-preventive properties.

11. Stress buster

Similar to other alcohols, beer reduces tension and promotes sleep.

12. Diuretic

Beer is a diuretic and increases urination greatly. This allows the enhanced elimination of toxins and waste from the body.

Types of Fermented Beer

Lager: Beers prepared with yeast that settles to the bottom of the container (Saccharomyces carlsbergensis). Thus, all yeast and other particles sink to the bottom, producing a clear beer.
Pilsner: Pilsner is an original colourless lager beer manufactured in the Czech city of Pilsen. The water used for this variety of beer is typically harder and contains more calcium and magnesium than lager water. Additionally, pilsner is lighter in colour than lager.

Ale: Beers prepared with yeast that floats to the top of the brewing vats (Saccharomyces cerevisiae), resulting in a cloudier beer. They often contain more alcohol than lagers.
Porter: A extremely black ale. Before brewing, malt is toasted to provide its deeper hue and distinctive flavour. This typically results in a more robust flavour and increased alcohol concentration.
Stout: A stout is a very dark, nearly black beer. The roasted barley and/or malt impart the dark hue and roasted flavour.

Raw material for beer production

Barley malt
Adjuvants
Hops

Tannin (help in precipitation of protein)
Water
Yeast

Steps of Beer Production

1. Malting

Producing beer from barley grains.
The grains of barley are first cleaned and then steeped in water for approximately two days. The barley is then incubated for four to five days to permit germination.
The germination processes result in the development of highly active α-amylase, β-amylase, and protease enzymes, as well as several flavour and colour components.

Malt adjuncts

Barley contains an abundance of protein. Therefore, if only barley is used to produce beer, the final product will be dark and unstable. Therefore, extra starch or sugar should be added to malt to dilute its protein content.
These sweet or starchy substances are known as malt adjuncts, and include dextrose sugar syrup.

2. Kilning

The germinated seeds are then killed by a gradual heating at 80 degrees Celsius. This procedure is known as kilning.

The temperature of the oven must not affect the amylase enzyme. Additionally, if the kilning temperature is increased, the resulting beer will be darker.

3. Mailing

The barley grains are next crushed between rollers to create grist, a coarse powder.

4. Mashing

The mixture of grist and warm water is kept at 65°C for approximately one hour.

The amylase enzyme hydrolyzes starch to create single sugars, maltose, dextrose, etc. Likewise, proteolytic enzymes hydrolyze protein into minute fragments and amino acids.
The extent of enzymatic hydrolysis is very sensitive to pH and temperature. -amylase has optimal activity between 57 and 65 degrees Celsius, whereas -amylase has optimal activity between 70 and 75 degrees Celsius.
The liquid resulting from mashing is known as wort. Filtration removes husks and other grain residues, as well as precipitated proteins.

5. Boiling of wort

The filtrate is then boiled for two to three hours, while hop flowers are added at various intervals.
Motives for boiling wort:
- For hop flavour extraction from hop flower, boiling coagulates remaining protein, partially hydrolyzes protein, and aids in protein removal.
- Enzymes that were active during mashing are inactivated by boiling; otherwise, sugar caramelization occurs.
- Furthermore, boiling sterilises and concentrates the wort.

6. Hops

Hops are the dried female flowers of the Humulus lupulus plant. A quarter-pound of hop flower is added to each barrel of beer, and up to two pounds every barrel of ale.

The benefits of adding hops to beer are:
- Give beer its spicy and fragrant characteristics
- Offer tannin, which facilitates the coagulation of leftover protein.
- Contains -resin and -resin, which impart bitter flavour and gram-positive bacteria preservation. Positive organisms
- Contains the pectin responsible for the distinctive foam of beer.

7. Fermentation

Saccharomyces carlsbergens and S. varum, which are bottom yeasts, and S. cerevisiae, which is a top yeast, are utilised in the creation of beer.

Typically, yeast cells for inoculation are recovered from a previous fermentation tank by reducing the pH using phosphoric acid, tartaric acid, or ammonium persulphate and removing a significant amount of bacterial contamination.
Typically, fermentation occurs at a temperature of 3 to 4 °C, but the temperature can range from 3 to 14 °C. Typically, fermentation is complete after 14 days.
During fermentation, yeast primarily transforms sugar into ethanol, carbon dioxide, glycerol, and acetic acid.

For fermentation, an open fermenter tank can be utilised, but a closed fermenter tank is preferred so that the CO2 produced during fermentation can be collected for the subsequent carbonation stage.
Maximum CO2 evolution occurs on the fifth day of fermentation, and there is no CO2 evolution between days 7-9 as yeast cells become dormant and flocculate.
Most beer has between 3.5% and 5% alcohol.

8. Finishing, Ageing, Maturation and Carbonation

Young and green beer is preserved in vats at 0 degrees Celsius for several weeks to months. During this time, unwanted particles such as protein, yeast, and resin precipitate, and the beer becomes clear.
During ageing, ester and other chemicals are formed, which impart flavour and aroma.
After ageing, the beer is carbonated with 0.45% to 0.52% carbon dioxide.

The beer is subsequently chilled, clarified, filtered, then bottled or canned.

9. Packaging

The packaging of beer is either in kegs or 330ml glass bottles. Each keg can store either 30 litres or 50 pints, or 50 litres or approximately 85 pints.
If the beer is bottled, it is counter-pressure filled (double pre-evacuation) to reduce oxidation and foam-capped to ensure that it is free of harmful microorganisms and will remain stable in the bottle.

10. Distribution

The delivery of kegs to bars and pubs, as well as their use for festivals and promotions.
The delivery of bottles to liquor stores, restaurants, bars, sporting clubs, etc.
Beer is relished and consumed.

The Continuous Fermentation Process

Fermentation is the process through which yeast transforms “sugars” into alcohol, carbon dioxide, and heat. Most traditional beers derive their sugars mostly from malted barley, although alternative cereal sources and plant sugars can also be employed. These components also provide proteinaceous compounds, which, when combined with sugars and other flavouring agents, most notably hops, produce the alcohol, tastes, and fragrances that make beer so appealing.

The fermentation system consists of a cascading series of three stirred pots and a fourth unstirred tank in which the beer and yeast are separated. The technique employs a yeast strain that settles rapidly following fermentation. From the fourth vessel, the clarified beer is transferred to a warm Maturation Vessel, where yeast action refines the flavour (from the small amount of residual yeast in the beer).

Depending on production requirements, the total time spent in these four vessels might range between 40 and 120 hours. All varieties of beer are created on a single, continuous manufacturing line, and their respective distinctions are made during the maturation stage. These are the numerous vessel actions:

1. Step 1 – The Hold-Up Vessel (Huv)

The wort is oxygenated to promote yeast growth, and a continual supply of yeast and beer from later in the fermentation process is combined with the wort as it enters this initial little jar.
Due to the high concentration of nutrients in wort, the introduction of yeast can be relatively stressful for the yeast. By combining wort with partially fermented beer, the concentration of nutrients is lowered, allowing for a more quick start to fermentation.
The yeast that is recirculated to the holding vessel is still fermenting, thus there is no substantial delay before the fermentation resumes.

The recycled partially fermented beer decreases the pH from 5.0 to 4.3 and raises the ethanol content in this vessel. This reduces the risk for microbiological deterioration by creating an unfavourable environment for competing microorganisms such as bacteria or wild yeast (yeast that is not the “culture” yeast of a certain brewery).
The beer/wort mixture resides in this vessel for around three to four hours.

2. Step 2 – Continuous Fermenter 1 (Cf1)

Continuous Fermenter 1 is the primary fermentation vessel from which partially fermented beer is returned to the holding vessel.

Depending on production demands, the typical residence period in this vessel exceeds thirty hours.

3. Step 3 – Continuous Fermenter 2 (Cf2)

Continuous Fermenter 2 is an important vessel for the final beer fermentation’s fine-tuning (that is, ensuring that the desired amount of ethanol is produced). The duration of stay in this vessel exceeds twelve hours.

4. Step 4 – Yeast Separator

This jar is unstirred and has a cone-shaped base. As the beer pours into the vessel, the yeast settles to the bottom of the cone and is piped back to the beginning of the fermentation, where it is mixed with the wort.

During fermentation, typically more yeast is created than is required by the brewery. The surplus yeast is washed to recover as much beer as possible (the wash water is later used to dilute the beer), and the yeast is then sold.

5. Step 5 – Maturation Vessel

This vessel’s primary function is to eliminate a fermentation byproduct with an unpleasant toffee/butterscotch flavour.
The flavour comes from 2,3-butanedione, a diketone molecule. Fermentation produces the precursor to this flavour component, “- acetolactate”‘.

The vessel’s high temperature and low pH accelerate the conversion of – acetolactate to 2,3-butanedione.
Once the flavour is generated, it is swiftly absorbed by the few remaining yeast cells to produce 2,3-butanediol, which has no discernible flavour. After two days, the beer is ready for cold storage to facilitate sedimentation and haze removal (Haze is due to complexes of polyphenols and proteins, if not removed they reduce the clarity of the beer).
During these post-fermentation processes, brands also diversify. The beer is then filtered and bottled (Campbell, 2017). Initially, the operations appear to be rather simple. When yeast is added to cooled wort, it consumes oxygen and nutrients and multiplies.

They will multiply until all oxygen is exhausted, at which point they will attack the carbohydrates in the beer. Beer fermentation can be so intense and release so much carbon dioxide that a foamy head can rise at least one foot above the beer’s surface.
The yeast fermentation produces alcohol, carbon dioxide, and other byproducts such as fusel alcohols (or fusel oils).
Fusel oils consist of congeners, a mixture of organic acids, higher alcohols (propyl, butyl, and amyl), aldehydes, and esters. It is believed that these Congeners produce hangovers.

This process continues until all of the simple sugars in the beer have been eaten. Some yeast are becoming dormant and sinking to the bottom, while others continue to consume the more complex sugars and other byproducts in the beer.
At some point, the yeast will have consumed all of the available food and will have no choice but to settle to the bottom of the fermenter and wait for new food. At this point, one decides whether or not to transfer the beer to a secondary fermenter.
This process typically takes around a week for the majority of beers. At higher fermentation temperatures, a greater number of byproducts (ranging from fruity esters to solvent-like fusel alcohols) are produced, imparting a fruity or phenolic flavour and aroma to the beer.

At lower temperatures, yeast acts considerably more slowly and produces fewer byproducts. This is one of the primary distinctions between lagers (cold-fermented) and ales (fermented warm).
Lagers have a considerably cleaner flavour than ales, with malt and hops flavours dominating. Ales, on the other hand, have far more complex scents and flavours, favouring fruity and spicy characteristics.
Temperature has a relatively linear relationship, however. There will be less “ale flavour” and more “lager character” in beers fermented at cooler temperatures.

In contrast, lagers fermented at a higher temperature will exhibit greater “ale character” with fruitier/spicier ester production.
The other distinction between the two types of yeast is that lager yeasts ferment at or near the bottom of the beer, whereas ale yeasts ferment at the top of the brew and eventually fall out.
Given that yeasts are ubiquitous, it makes natural that some have evolved to cooler regions.

Maize beer production procedures

1. Treatment Of Maize Grains

The objective of this phase is to produce safety grains. Detoxification of grain prior to malting may not be feasible unless further mould growth is also prevented.
Physical, biological, chemical, and biological methods are used to prevent the growth of mould on grains.

2. Germination Or Malting

Grain is soaked in water, which the grain absorbs. There is hydration of the grain embryo and stimulation of the germinating grain.

The activities of the embryo are stimulated, and enzymes are equally dispersed throughout the kernel.
The grain is placed in shallow jars, and the moisture is extracted. The aleurone layer is induced to generate enzymes that breakdown cell wall structures. In maize grain, the aleurone layer stimulates enzymes, resulting in the breakdown of proteins, carbohydrates, hemicellulose, and lipids.
The temperature of the malt is gradually increased from 15 to 85 degrees Celsius (temperature, airflow, time).

At the appropriate malt quality, the germination process is stopped, green brown malt is turned into a stable, storable product, colour and flavour are developed, enzymes are stabilised and conserved, and undesirable flavours are eliminated.

3. Extraction With Water Or Mashing

Mixing milled grain with water at varying temperatures, rest durations, and agitation levels. Temperatures are optimum for malt enzymes as follows: 50°C for proteolysis, 62°C for gelatinization/liquefaction, 72°C for saccharification, and 78°C for mashing-off and deactivation of malt enzymes.
In addition to solubilization and dissolution of grain components, grain cell wall structure is broken down, starch, sugars, proteins, and non-starch polysaccharides are extracted and hydrolyzed, and a fermentable sugar profile is created.

The wasted grains are removed from the wort (aqueous solution) at 78°C. Hot water is sparingly applied to the grain bed to extract as much extract as feasible.
The degree of clarity and extract concentration of the wort are determined. During the boil at 100°C, hops are added to the wort.
There occurs water evaporation, protein coagulation, isomerization of hop bitter components, enzyme inactivation, wort sterilisation, evaporation of unwanted volatiles, synthesis of flavour compounds, and colour development.

4. First Filtration

The separation of insoluble particles from the wort solution.
The removal of coagulated proteins and insoluble hops material.

5. Fermentation

The wort solution is chilled to yeast pitching temperature (21 to 25 degrees Celsius). Reduced temperature permits yeast addition; yeast is added to sterile, cooled wort (cold temperatures encourage precipitation of proteins and beer clarification).

Yeast utilises the carbohydrates and proteins in the wort to produce alcohol, carbon dioxide, and taste components via the following chemical reaction: C6H12O6 → 2C 2 H 5OH + 2CO2
At the conclusion, the alcohol level, flavour profile, and carbonation level are set, and the yeast flocculates and can be readily separated (Cold maturation temperatures will influence beer clarity).

6. Second Filtration

After fermentation has concluded, the beer is filtered to eliminate the yeast and any other solid byproducts.

Following filtration, the clear product is bottled.