PRODUCTION OF BEER IN INDUSTRIA SETTING.

This presentation is about beer production. It covers categories of beer, examples of beer and their industrial production

1. PRODUCTION OF BEER RAW MATERIALS AND BREWING PROCESS GROUP D

2. BARLEY BEERS The word beer derives from the Latin word bibere meaning to drink. The process of producing beer is known as brewing. Beer brewing from barley was practiced by the ancient Egyptians as far back as 4,000 years ago, but investigations suggest Egyptians learnt the art from the peoples of the Tigris and Euphrates where man’s civilization is said to have originated. However, the use of hops is much more recent and can be traced back to a few hundred years ago.

3. Types of Barley Beers Barley beers can be divided into two broad groups: Top-fermented beers Bottom fermented beers. This distinction is based on whether the yeast remains at the top of brew (top-fermented beers) or sediments to the bottom (bottom-fermented beers) at the end of the fermentation .

4. Bottom-fermented beers Bottom-fermented beers are also known as lager beers because they were stored or ‘lagered’ ( from German lagern = to store ) in cold cellars after fermentation for clarification and maturation. Yeasts used in bottom-fermented beers are strains of Saccharomyces uvarum (formerly Saccharomyces carlsbergiensis ). Several types of lager beers are known. They are named after the cities they originated from: Pilsener from Pilsen (former Czechoslovakia), Dortmunder from Dortmund, and Münchner from Munich (Germany). Most of the lager beers in the world (70%–80%) are of the Pilsener type.

5. Bottom-fermented beers Cont… Bottom-fermentation was a closely guarded secret in the Bavarian region of Germany, of which Munich is the capital. Legend has it that in 1842 a monk passed the technique and the yeasts to Pilsen. Three years later, they found their way to Copenhagen, Denmark. Shortly after, German immigrants introduced bottom-brewing to the US.

6. Bottom-fermented beers Cont… ( i ) Pilsener beer: This is a pale beer with a medium hop taste. Its alcohol content is 3.0–3.8% by weight. Classically, it is lagered for two to three months, but modern breweries have substantially reduced the lagering time which has been cut down to about two weeks in many breweries around the world. The water for Pilsener brew is soft, containing comparatively little calcium and magnesium ions. (ii) Dortmunder beer: This is a pale beer, but it contains less hops (and therefore is less bitter) than Pilsener. However, it has more body (i.e. it is thicker) and aroma. The alcohol content is also 3.0–3.8% and is classically lagered for slightly longer: 3–4 months. The brewing water is hard, containing large amounts of carbonates, sulfates, and chlorides.

7. Bottom-fermented beers Cont…… (iii) Münchner: This is a dark, aromatic, and full-bodied beer with a slightly sweet taste, because it is only slightly hopped. The alcohol content could be quite high varying from 2 to 5% alcohol. The brewing water is high in carbonates but low in other ions. (iv) Weiss ( Weizen ): Weiss beer of Germany made from wheat and steam beer of California, USA, are both bottom fermented beers which are characterized by being highly effervescent.

8. Top-fermented beers Top-fermented beers are brewed with strains of Saccharomyces cerevisiae. ( i ) Ale: Whereas lager beer can be said to be of German or continental European origin, ale (Pale ale) is England’s own beer. English ale is a pale, highly hopped beer with an alcohol content of 4.0 to 5.0% (w/v), sometimes as high as 8.0%. Hops are added during and sometimes after fermentation. It is therefore very bitter and has a sharp acid taste and an aroma of wine due to its high ester content

9. Top-fermented beers Cont… Mild ale is sweeter because it is less strongly hopped than the standard Pale ale. In Burton-on-Trent, where the best ales are made, the water is rich in gypsum (calcium sulfate). When ale is produced in places with less suitable water, such water may be ‘burtonized ’ by the addition of calcium sulfate (ii) Porter: This is a dark-brown, heavy bodied, strongly foaming beer produced from dark malts. It contains less hops than ale and consequently is sweeter. It has an alcohol content of about 5.0%. (iii) Stout: Stout is a very dark heavily bodied and highly hopped beer with a strong malt aroma. It is produced from dark or caramelized malt; sometimes caramel may be added. It has a comparatively high alcohol content, 5.0–6.5% (w/v) and is classically stored for up to six months.

10. RAW MATERIALS FOR BREWING The raw materials used in brewing are: Barley Malt Adjuncts Yeasts Hops And Water.

11. 1: Barley Malt Barley is essential due to its thick husks, aiding in malting, filtration, and protection against fungi during storage. Barley has a low gelatinization temperature (52–59°C), allowing efficient starch conversion with naturally high beta-amylase content. B arley are of two types: six-row ( Hordeum vulgare ) rich in protein and enzymes, commonly used in the US, and two-row ( Hordeum distichon ).

12. 2: Adjuncts Adjuncts, like sorghum, maize, rice, cassava, and potatoes, complement malt by providing fermentable sugars and reducing costs. Initially used in the US to balance six-row barley's high diastatic power, now includes sucrose to increase alcohol content. Low in nitrogen, adjuncts need malt for yeast nutrients, with typical malt/adjunct ratios not exceeding 60/40.

13. CONT…. 3: Hops Hops, the dried female flowers of Humulus lupulus , provide bitterness and aroma due to resins and essential oils. Modern brewing often uses hop extracts, with 0.4–4.0 g/liter added based on beer style. Hops improve beer by enhancing bitterness, aroma, foam retention, body, and acting as natural preservatives with antimicrobial effects.

14. CONT…. 4: Water Mineral content, ions, and pH in water significantly influence beer production, with calcium enhancing flavor. High calcium and bicarbonate levels favor darker beers, while low-mineral water suits pale beers. To treat carbonate-rich water, methods include adding calcium sulfate, acids, lime, or using ion exchange.

15. CONT…. 5: Brewer's Yeast Brewing yeasts , S. cerevisiae (top-fermenting) and S. uvarum (bottom-fermenting), produce alcohol and flavor compounds. S. uvarum ferments raffinose , while S. cerevisiae only ferments fructose , with bottom-fermenting yeasts settling at the bottom. Yeasts are reused in brewing, but mutation and contamination pose risks.

16. Brewery Processes The processes involved in the conversion of barley malt to beer may be divided into the following: Malting Cleaning and milling of the malt Mashing Mash operation Wort boiling treatment Fermentation Storage or lagering 8. Packaging

17. Malting The purpose of malting is to develop amylases and proteases in the grain. These enzymes are produced by the germinated barley to enable it to break down the carbohydrates and proteins in the grain to nourish the germinated seedling before its photosynthetic systems are developed enough to support the plant . However, as soon as the enzymes are formed and before the young seedling has had any appreciable impact on the nutrient reserve of the grain, the development of the seedling is halted by drying , but at temperatures which will not completely inactivate the enzymes in the grain.

18. Malting….. These enzymes are reactivated during mashing and used to hydrolyze starch and proteins and release nutrients for the nourishment of the yeasts. Not all barley strains are suitable for brewing. During malting, barley grains are cleaned; broken barley grains as well as foreign seeds, sand, bits of metal, etc. are removed. The grains are then steeped in water at 10–15°C. The grain absorbs water and increases in volume ultimately by about 4% and Respiration starts . Microorganisms grow in the steep water, and to allow grain deterioration, the steep water is changed approximately at 12-hourly intervals until the moisture content of the grain is about 45%. Steeping takes two to three days .

19. The grains are then drained of the moisture and may be transferred to a malting floor or a revolving drum to germinate. The heat generated by the sprouts further hastens germination. The grain itself synthesizes gibberellic acid which then triggers the synthesis of various hydrolytic enzymes by the aleurone layer consider Figure 1 situated on the periphery of the grain. The enzymes so formed diffuse into the center of the grain where the endosperm is located.

20. Figure 1

21. Alpha-amylase is also synthesized by the grain. Beta-amylase is already present and is not synthesized but is bound to proteins and is released by proteolytic enzymes ‘Modification’ or production of enzymes is complete in four to five days of the growth of the seedling, the extent being tested roughly by the sweet taste developed in the grain and by the length of the young plumule . As these processes are to be halted by kilning but actually the temperature applied depends on the type of beer the brewer wants for example pilsener pale beer , munich dark beer and strout very dark are placed at a temperature of 80-90 , 100-110 , and 120 respectively

22. Cleaning and milling of malt The barley is transported to the top of the brewing tower. Subsequent processes in the brewery process occur at progressively lower floors. Lagering and bottling are usually done on the ground level floor. In this way, gravity is used to transport the materials and the expense of pumping is eliminated. At the top of the brewing tower, the barley malt is cleaned of dirt and passed over a magnet to remove pieces of metals, particularly iron, and then milled to expose particles of the malt to the hydrolytic effects of malt enzymes during the mashing process

23. The finer the particles the greater the extract from the malt. But the brewer must be so sensitive to the size of particles by finding a compromise particle which will be suitable for extraction yet permit reasonably rapid filtration rate . During crushing the preservation of the husk is prominent as it contributes in filtration processes. MASHING Mashing determines the nature of the aqueous solution known as wort , hence the nature of the nutrients available to the yeasts and therefore the type of beer produced .

24. The purposes of mashing: To extract the soluble portion of the malt as much as possible and To enzymatically hydrolyze insoluble portions of the malt and adjuncts. The two contents in terms of dry weight of the grain are in malt starch Protein The controlled breakdown of these two components has tremendous influence on beer character.

25. STARCH BREADOWN DURING MASHING Starch forms about 55% of the dry weight of barley malt. Of the malt starch, 20-25% is made up of amylose. The key enzymes in the breakdown of malt starch are Alpha amylase work best at a temperature of 68-70°C and at pH of 5.8 Beta-amylases working best at 60-65°C at a pH of 5.4 PROTEIN BREAKDOWN DURING MASHING The breakdown starts during malting and continues during mashing where proteins are broken to peptones, polypeptides and amino acids. Protein breakdown has no pronounced optimum temperature, but during mashing, it occurs evenly up to 60°C.

26. NB: The progress of mashing is affected by a combination of temperature, pH, time, and concentration of the wort. When the temperature is held at 60–65°C for long periods, a wort rich in maltose occurs because beta amylase activity is at its optimum, and this enzyme yields mainly maltose. On the other hand, when a higher temperature around 70°C is employed, dextrins predominate and it contribute to the body of the beer but are not utilized by yeast. Hence Mash exposed to too high a temperature will therefore be low in alcohol due to insufficient maltose production.

27. 4.MASH OPERATION. Consists of two main activities Mashing methods Mash separation a)Mashing methods: There are three major mashing methods: Decoction methods: where part of the mash is transferred from the mash tun ( fig 2) to the mash kettle where it is boiled. Infusion methods: where the mash is never boiled, but the temperature is gradually raised. The double mash method: in which the starchy adjuncts are boiled and added to the malt

28. b) Mash separation It is done under two main activities 1.Wort separation from the solids husks and other solid unwanted materials 2.Washing and sparging of the solids with hot water to free them from further extractible materials 1.Wort separation from the solids husks and other solid unwanted materials: The conventional method of separating the husks and other solids from the mash is to strain the mash in a lauter (German for clarifying) tub which is a vessel with a perforated false-bottom about 10 mm above the real bottom ( Fig 3) on which the husks themselves form a bed through which the filtration takes place

29. fig 2 Fig 3 False bottom Real bottom

30. RECENTLY especially in the United States, the Nooter strain master has come into use. Like the Lauter tub, filtration is through a bed formed by the husks but instead of a false bottom, straining is through a series of triangular perforated pipes placed at different heights of the bed. The strain master itself is rectangular with a conical bottom whereas the Lauter tub is cylindrical. Its advantage among others is that it can handle larger quantities than the Lauter tub. Besides the Lauter tub and the strainmaster , cloth filters located in plate filters and screening centrifuges are also used

31. 2 .Washing and sparging of the solids with hot water to free them from further extractible materials. The sparging (or washing with hot water) of the mash solids is done with water at about 80°C and is continued, until the extraction is complete. The material which is left after sparging is known as spent grain and is used as animal feed. Sometimes, liquid is extracted from the spent grain by centrifuging, the extract being used to cook the adjuncts.

32. Steps cont.,, 4. Fermentation Fermentation Overview Process : Cooled wort is transferred to fermentation tanks where yeast is added (pitched) at a density of 7–15 million yeast cells per milliliter. Yeast Source: Yeast is often collected from previous batches. Key Products: Fermentable sugars are converted into alcohol, carbon dioxide (CO₂), and heat.

33. Steps cont … Top Fermentation (for Stout and Ale) Yeast Strain: Saccharomyces cerevisiae. Conditions: Wort is aerated to 5–10 mg/L oxygen; yeast pitched at 15–16°C. Temperature rises to 20°C over three days, then cooled. Duration: Primary fermentation lasts ~6 days. Key Characteristics: Yeast floats to the top and is skimmed off for reuse. May involve transferring the wort to remove sediments (dropping system). Modern closed cylindrical tanks are now common.

34. Cont … Bottom Fermentation (for Lager) Yeast Strain: Pitched at 6–10°C, temperature rises to 10–12°C over 3–4 days, then cooled to ~5°C. Duration: Fermentation lasts 7–12 days. Key Characteristics: Yeast settles at the bottom. Produces a CO₂ head (Krausen) that collapses as fermentation completes.

35. Steps cont.. Byproducts of Fermentation:- Alcohol and CO₂: Generated from fermentable sugars. Higher Alcohols (Fusel Oils): Propanol, isobutanol from amino acids. Organic Acids: Acetic, lactic, pyruvic, citric, and malic acids from carbohydrates. Non-Fermented Sugars: Dextrins and maltotetraoses remain unfermented.

36. Steps cont.. Monitoring Fermentation Specific Gravity: Decreases during fermentation as sugars are consumed and alcohol (lower gravity) forms. Measurement Systems: In the UK: Extract measured as specific gravity x 1000 (e.g., 1.053 → 1053°). Globally: °Balling, °Brix, and °Plato indicate sucrose percentage for specific gravity.

37. Steps cont …… 5.Lagering (Bottom-Fermented Beers): Involves secondary fermentation of "green beer" at low temperatures (~0°C) to mature and refine flavors. Reduces harsh compounds (e.g., diacetyl) and enhances desirable components (e.g., esters). Traditional lagering took months, now shortened to days using temperature control and artificial carbonation.

38. Steps cont ….. Beer Treatment (Top-Fermented Beers): Less extensive than lagering, involving cask or bottle conditioning. Sugar and caramel may be added for carbonation and flavor. Fined with isinglass to remove unwanted particles, then filtered or pasteurized. 6.Packaging: Beer is transferred under CO₂ pressure to prevent oxidation and contamination. Bottles are pasteurized to ensure safety, but bulk pasteurization is increasingly used.

39. BEER DEFECTS Biological Turbidities: Caused by spoilage organisms like wild yeasts and bacteria (e.g., Lactobacillus , Acetobacter ). Physico -chemical turbidities: From metals, protein-tannin complexes, polysaccharides, or oxalate. Other Issues: Includes gushing (over-foaming) caused by contaminants like Fusarium in malt.

40. DEFECTS CONT… HOW DO WE REMOVE PROTEIN TANNIN HAZE? Papain (breaks polypeptides). Silica gel or bentonite (adsorbs polypeptides). Tannic acid (precipitates polypeptides). Nylon resins (adsorbs polyphenols). Polysaccharide Sediments: Haze caused by carbohydrate flakes, mainly beta-glucans from malt, appearing after freezing and thawing. Oxalate Sediments: Occur in beers high in oxalate with low calcium content, forming sediment over time.

41. DEFECTS CONT… Metal-Induced Hazes: Caused by metals like tin, copper, and iron. Tin precipitates haze precursors directly, while copper and iron catalyze polyphenol oxidation. EDTA can chelate these metals to prevent hazes. Protein-Tannin Hazes: Formed by reactions between polyphenols (from hops and barley) and proteins. Types: Chill Haze: Forms at low temperatures (0°C), dissolves at higher temperatures (20°C). Permanent Haze: Remains insoluble at all temperatures.

42. Continuous Brewing Continuous brewing is a fermentation process that operates without interruption. It generally occurs in two main types: Open System Partially Closed System

43. 1. Open System How it Works: Wort (unfermented beer) is continuously fed into a fermenter, and beer flows out at the same rate. Yeast reaches a natural steady state during the process. The wort undergoes three stages in separate tanks : First Tank: Oxygen is added to support yeast growth. Second Tank: Conditions become anaerobic, resulting in the production of alcohol and CO₂. Third Tank: The beer, along with suspended yeast, overflows into a vessel for sedimentation.

44. Disadvantages of Open Systems Yeast from the sedimentation tank is recycled to the first tank, increasing the risk of contamination and quality issues. Recycled yeast differs physiologically from actively fermenting yeast, potentially compromising the quality of the wort and beer.

45. 2. Partially Closed System Process: Sterilized wort is pumped into the base of a fermenter with aeration, and beer is drawn off from the top at the same rate. The fermenter’s lower section contains a high yeast concentration (350–400 g/L), enabling rapid and efficient fermentation. The upper section has less yeast and serves as a finishing area for fermentation and yeast separation from beer. Inside the fermenter, baffles guide the flow of CO₂ and beer, ensuring efficiency and proper exit points.

46. Use of Enzymes Enzymes derived from bacteria and fungi are used to replace malt in brewing, offering several advantages: Reduces costs by eliminating the malting process. Reduces dependency on barley farming. Challenges: Enzymes must be free of toxins, which is difficult to achieve on a large scale. Established industries such as barley farming and malting could be adversely affected.

47. SORGHUM BEER PRODUCTION Sorghum beer is a traditional African beer made from sorghum, a drought-resistant cereal , scientific name is sorghum bicolor , in US as milo,in south Africa as kaffir corn and west Africa as guinea corn. Mixed with maize or millets Characteristics of sorghum beer : Pinkish, sour, and thick due to starch particles. Consumed unaged and unclarified, with live yeast and bacteria. Involves lactic fermentation.

48. Sorghum Beer Production cont … … Types: Known by various names, including burukutu (Nigeria), pombe (East Africa), and kaffir beer (South Africa). Malting: Sorghum grains are soaked, then drained and allowed to germinate for 5–7 days, after that dried. Germination produces enzymes like α- amylase, but ungerminated sorghum lacks β- amylase (present in barley). Saccharification of sorghum starch is done by these fungi which are Rhizopus oryzae , aspergillus flavus ,penicillium funiculosum and penicillium citrinum

49. Sorghum beer production cont ….. Mashing : Malt is ground, mixed with water in ratio of 6:1, and boiled for some time,Starch adjuncts such as cassava or maize powder, are added to enhance fermentation and contribute to the proportion in ratio of 1:2:6. Fermentation : Two types of fermentation occur: Lactic Acid Fermentation: Alcoholic Fermentation:

50. Inoculum consist of:- Yeasts (e.g., Saccharomyces cerevisiae) produce alcohol Methods. Example of yeast found in sorghum beer from Nigeria are candida spp ,S cerevisiae, S. chevalieri : Lactic acid bacteria consist of Lactobacillus plantarum and Lactobacillus mesenteroides , occur naturaly in grains .found in first phase of fermentation produce lactic acid Acetic acid bacteria . These produce flavor of beer by produce acetic acid

51. Traditional Method : Uses dregs from previous fermentation as a starter. Industrial Method (South Africa): Temperature is carefully controlled to encourage bacterial growth. Unique Traits of Sorghum Beer Contains solids (starch and microorganisms), making it both a food and a drink. No secondary fermentation or aging; ready in 48 hours. Often has a vinegary taste due to acetic acid bacteria .