Lesson 4 Alcohol Fermentation PDF

Lesson 4 Alcohol Fermentation ROLENZ DERICK R. CRUZ Food Technology Department FT16 Food Processing II BU College of Industrial Technology 1 © 2024 Rolenz Derick Cruz...

Lesson 4 Alcohol Fermentation ROLENZ DERICK R. CRUZ Food Technology Department FT16 Food Processing II BU College of Industrial Technology 1 © 2024 Rolenz Derick Cruz AI-generated image © 2024 Rolenz Derick Cruz All rights reserved. This work is an intellectual property of the author. Redistribution or sale of any part of this presentation and lecture without prior consent of the author is not allowed. 2 © 2024 Rolenz Derick Cruz Lesson Outcome At the end of the lesson, you should be able to: – Explain the principles of alcohol fermentation, including its purpose and the process involved, highlighting key steps and factors affecting fermentation. – Execute the process of making a simple fruit wine, demonstrating proficiency in fermentation techniques and the ability to follow procedural steps accurately. 3 © 2024 Rolenz Derick Cruz Lesson Outline 1. Alcohol 2. Alcohol Fermentation 3. Wine & Wine-making 4. Factors Affecting Yeast Growth 5. Spoilage of Fruit Wines & its Prevention 6. Beer & Beer-making 7. Distillates (BWVGRT) 8. Filipino Alcoholic Beverages 4 © 2024 Rolenz Derick Cruz Alcohol Alcohol is a colorless, volatile liquid with no distinct odor. Of all alcohols, only ethyl alcohol is safe for human consumption. EtOH is produced through the fermentation of sugars by yeast, a process central to creating alcoholic beverages such as beer, wine, and spirits. With a BP of 78.3°C, etOH evaporates more quickly than water, allowing for the concentration of alcohol through distillation. – This process is used to produce high-alcohol-content spirits like whiskey, vodka, and rum. 5 © 2024 Rolenz Derick Cruz Alcohol Alcohol strength can be measured using three common methods: 1. Proof (a traditional scale used in some countries) 2. % v/v (percentage of alcohol by volume) 3. °GL (degrees Gay-Lussac, which also indicates alcohol by volume) 𝟏% 𝒗/𝒗 = 𝟐 𝑷𝒓𝒐𝒐𝒇 = 𝟏 °𝑮𝑳 Photo from thegazette.com 6 © 2024 Rolenz Derick Cruz Alcohol Fermentation Alcohol is produced from glucose by the action of the alcohol-producing yeast Saccharomyces cerevisiae. In 1810, Gay-Lussac established the fermentation formula: 𝑪𝟔𝑯𝟏𝟐𝑶𝟔 → 𝟐 𝑪𝟐𝑯𝟓𝑶𝑯 + 𝟐 𝑪𝑶𝟐 Photo from thegazette.com 7 © 2024 Rolenz Derick Cruz Alcohol Fermentation Tuba 2.0 – 4.0% Beer 2.0 – 12% (usually 4 – 6%) Wine 5.5 – 16% (usually 12.5 – 14.5%) Basi 10 – 15% Tapuy 14 – 19% Sake 15% (or 18 – 20%) Soju 14 – 45% (usually 17%) Photo from thegazette.com 8 © 2024 Rolenz Derick Cruz Alcohol Fermentation Tequila 32 – 60% (usually 40%) Vodka 35 – 95% (usually 40%) Rum 37.5 – 80% (usually 40%) Brandy 35 – 60% (usually 40%) Gin 37.5 – 50% Lambanog 40 – 45% Whisky 40 – 68% (usually 40%) Photo from thegazette.com 9 © 2024 Rolenz Derick Cruz Wine Wine is an alcoholic beverage made from the fermentation of fruit juice, most commonly grape juice. Wine can also be produced from other fruits such as apples, berries, and peaches, and even from herbs. Since wine is fermented and undistilled, it retains many of the nutrients present in the original fruit, though the fermentation process changes its composition. 10 © 2024 Rolenz Derick Cruz Wine Wines are often aged in wooden barrels (typically oak) to enhance their flavor, aroma, and overall quality through a process known as maturation. Aging in barrels allows the wine to develop more complex flavors as it interacts with oxygen and compounds in the wood. 11 © 2024 Rolenz Derick Cruz Wine The flavor of wine improves with age due to a series of complex chemical reactions involving sugars, acids, and phenolic compounds (such as tannins). Over time, these reactions refine the wine's taste, contributing to a more balanced and pleasing flavor. 12 © 2024 Rolenz Derick Cruz Wine The distinctive character of a wine is influenced by several factors: ▪ Composition of the raw material – The type and quality of the fruit used, particularly the grape variety. ▪ Nature of the fermentation process – The specific yeast strains, temperature, and duration of fermentation play a critical role. ▪ Processing and aging treatments – Techniques such as barrel aging, filtration, and blending affect the final product's taste and texture. 13 © 2024 Rolenz Derick Cruz Types of Wine 1. Table Wine – Typically has a lower alcohol content (usually under 14%) and little to no residual sugar, making it dry. – It is often consumed with meals. 14 © 2024 Rolenz Derick Cruz Types of Wine 2. Still Wine – Non-carbonated wine, available in red, white, or rosé varieties ▪ Red Wine – Made from dark- skinned grape varieties, with the grape skins included during fermentation. ▪ White Wine – Made from either white (green or yellow) grapes, or from red grapes with the skins removed before Photo from Wine Folly fermentation. 15 © 2024 Rolenz Derick Cruz  16 © 2024 Rolenz Derick Cruz Types of Wine 3. Sparkling Wine – Carbonated wine, either through natural fermentation (as in Champagne) or artificial carbonation. 17 © 2024 Rolenz Derick Cruz Types of Wine 4. Fortified Wine (or Dessert Wine) – Wine to which spirits, often brandy, are added, increasing the alcohol content (typically 15-20%). – These wines can be either red or white and are often sweet. – Examples include port, sherry, and Madeira. 18 © 2024 Rolenz Derick Cruz Types of Wine 5. Fruit Wine – Made from fruits other than grapes, such as apples, berries, or peaches. – These wines have varied flavors and alcohol content. 6. Natural Wine – Produced with minimal chemical additives or technological interventions. – Natural wines focus on sustainable and organic practices and appeal to consumers seeking less processed options. – Alcohol content may vary, but there is no strict cap on it. 19 © 2024 Rolenz Derick Cruz  Types of Wine 7. Medicinal Wine – Flavored with extracts of herbs or botanicals known for their medicinal properties. – Historically used for health purposes. Photos from The Philippine Craft Kings 20 VIDEO: 7 Wine Facts and Myths © 2024 Rolenz Derick Cruz Fruit Winemaking Preparation of Yeast Starter Culture 1. A quality strain of wine yeast, typically Saccharomyces cerevisiae, is essential for producing high-quality wine. 2. Before being added to the must (the juice or pulp), the yeast is activated in a small portion of the juice or pulp intended for winemaking (known as a "starter culture"). 3. The starter culture is covered and kept in a warm environment (25–30°C). The yeast will become active and ready for use after ~ 24 hr. Yeast starter culture 21 © 2024 Rolenz Derick Cruz Fruit Winemaking Preparation of Must 1. The must is prepared based on the type of fruit and the desired wine. ▪ For some fruits, like apples, the juice is directly extracted. ▪ For other fruits, the fruit is processed into a pulp before fermentation. 2. Pectinase is commonly added to the must to break down pectin, helping to clarify the wine. 22 © 2024 Rolenz Derick Cruz Fruit Winemaking Preparation of Must 3. Potassium metabisulfite is added to inhibit browning and prevent microbial growth. 4. To promote efficient fermentation, ammonium sulfate, along with vitamins like thiamine and biotin, may be added as nutrients. 5. The must can be gently heated (50°C for 35 min) to enhance the breakdown of fruit components and encourage fermentation. 23 © 2024 Rolenz Derick Cruz Fruit Winemaking Fermentation 1. The must is inoculated with the prepared yeast starter and allowed to ferment at a controlled temperature of 20–25°C. 2. Temperatures above 25°C should be avoided as they can cause the loss of volatile aroma compounds and ethanol. 3. Fermentation containers should be equipped with airlocks to allow CO₂ to escape while preventing oxygen from entering. 24 © 2024 Rolenz Derick Cruz Fruit Winemaking Fermentation 4. Sugar levels are monitored regularly during fermentation to track progress. Typically, fermentation continues until the sugar level is reduced to around Refractometer 8°Brix (nearly all sugars are consumed). 5. Once fermentation is complete, the production of CO₂ (visible as bubbling) ceases. 25 © 2024 Rolenz Derick Cruz Fruit Winemaking Siphoning 1. After fermentation, the yeast and other sediments settle at the bottom of the container. The clear wine is siphoned off to separate it from the sediment. If a pulpy must was used, it is filtered through cheesecloth before siphoning. 2. It is important to avoid any headspace in the storage container or bottle to prevent oxidation, which could lead to spoilage (acetification). The container is sealed tightly. 26 © 2024 Rolenz Derick Cruz Fruit Winemaking Maturation 1. Freshly made wine tends to be harsh and may have a strong yeasty flavor. 2. Maturation improves the wine’s taste, making it mellower, with more pronounced fruity flavors. It also helps in natural clarification. 3. Maturation time can range from 6 months to 2–3 years, depending on the type of wine. 4. During maturation, complex chemical processes occur, including the formation of esters, which enhance the wine’s aroma and flavor profile. 27 © 2024 Rolenz Derick Cruz Fruit Winemaking Clarification 1. If the wine remains cloudy after siphoning and maturation, it can be clarified using fining agents or filtering aids. ▪ Common fining agents include bentonite, casein, and pectic enzymes. 2. These treatments help make the wine crystal clear, improving its visual appeal. 28 © 2024 Rolenz Derick Cruz Fruit Winemaking Pasteurization 1. Wines can be pasteurized at 62°C for 15–20 min, usually after leaving some headspace in the bottle, which is then sealed with a crown cork. 2. Pasteurization helps precipitate tannins, reducing bitterness and improving the flavor. 3. Once pasteurized wine is opened, it must be stored at a low temperature to prevent spoilage. Photo from Coastal Wine Trail 29 © 2024 Rolenz Derick Cruz  Fruit Winemaking 1. Preparation of Yeast Starter Culture 2. Preparation of Must 3. Fermentation 4. Siphoning 5. Maturation 6. Clarification 7. Pasteurization 30 VIDEO: Wine - How It's Made © 2024 Rolenz Derick Cruz Spoilage of Fruit Wines Must Spoilage ▪ Wild yeasts – can cause off-flavors and compete with the desired yeast strains. ▪ Lactic acid bacteria – may lead to undesirable acid production and spoilage. ▪ Acetic acid bacteria – convert alcohol into acetic acid (vinegar) and cause spoilage. To prevent oxidation and microbial spoilage, add potassium or sodium metabisulfite before fermentation. For one gallon of must, add 5 mL of a 10% metabisulfite solution. 31 © 2024 Rolenz Derick Cruz Spoilage of Fruit Wines Spoilage During Fermentation ▪ Schizosaccharomyces – a wine-spoilage organism that produces compounds with negative sensory impacts, such as: o Acetaldehyde – contributes to a stale or sherry-like odor. o Hydrogen sulfide (H₂S) – produces a rotten egg smell. o Volatile acids – cause unpleasant sour or vinegar-like aromas. 32 © 2024 Rolenz Derick Cruz Spoilage of Fruit Wines Post-Fermentative Spoilage ▪ Saccharomyces – typically not a spoilage organism unless present in wines with residual sugars (sweet wines). It can cause refermentation, especially if not properly stabilized. ▪ Zygosaccharomyces – it can also cause refermentation in wines with residual sugars. 33 © 2024 Rolenz Derick Cruz Spoilage of Fruit Wines Post-Fermentative Spoilage ▪ LAB spoilage types: o Sugar fermentation – LAB can ferment residual sugars, producing acids, resulting in a sour aroma. o Organic acid fermentation – LAB can cause unpleasant aromas and flavors, producing compounds like diacetyl (buttery aroma) and acetone (nail polish remover). o Ropiness – certain LAB strains, such as Leuconostoc and Pediococcus, can produce dextran slime, resulting in a viscous, rope-like texture in the wine. 34 © 2024 Rolenz Derick Cruz Spoilage Prevention 1. Ethanol concentration and acidity – High ethanol concentrations (typically up to 19% v/v) and elevated acidity (pH 3.0–4.5) in wine can inhibit the growth of many bacterial species, reducing the risk of spoilage. 2. Temperature control – Storing wine below 15°C helps to minimize bacterial growth and proliferation. – Cooler temperatures slow down microbial activity and spoilage processes. 35 © 2024 Rolenz Derick Cruz Spoilage Prevention 3. Proper sanitation – Maintaining rigorous hygiene practices during all stages of winemaking—preparation, fermentation, and bottling—is crucial to preventing contamination and spoilage. 4. Sulfitation – Adding sulfur dioxide (SO₂) to wine after fermentation can help inhibit microbial growth and oxidation. – However, this practice is less common in natural or artisanal wines due to concerns about its impact on the wine’s organoleptic qualities (flavor, aroma, and mouthfeel). 36 © 2024 Rolenz Derick Cruz Spoilage Prevention 5. Chemical preservatives ▪ Metabisulfite – Used to control oxidation and microbial growth. ▪ Sulfur dioxide (SO₂) – effective against a broad range of microorganisms and helps preserve the wine’s freshness and stability. ▪ Ascorbic acid – an antioxidant that helps prevent oxidation and maintains color stability – Excessive use of chemical preservatives can negatively affect the wine's sensory qualities, such as flavor, aroma, and balance, and may also reduce its nutritional value. 37 © 2024 Rolenz Derick Cruz Beer Production an alcoholic beverage made primarily from barley malt, Beer which may be combined with other cereal grains (such as rice, corn, sorghum, and wheat) and flavored with hops. 38 © 2024 Rolenz Derick Cruz Ingredients of Beer 1. Barley – Contains up to 80% starch and the enzyme diastase, which converts starch into fermentable sugars. diastase fermentable starch sugars 39 © 2024 Rolenz Derick Cruz Malting Process 1. Soaking – Barley grains are soaked in water until they reach about 40–45% moisture content, initiating germination. 2. Germination – The grains sprout, activating diastase, which converts starch into sugar. 3. Kilning – After 4-5 days of germination, the process is halted by drying the sprouted grains. 4. Temperature control ▪ Low-temperature drying – Preserves enzyme activity and prevents caramelization of sugars. ▪ High-temperature drying – Creates specialty malts with inactive enzymes and caramelized sugars. 40 © 2024 Rolenz Derick Cruz Types of Malt 1. Pale malt – the base malt, dried at around 50°C. 2. Crystal malt – treated with controlled heating to develop sweetness and color. 3. Amber malt – dried at slightly higher temperatures, providing a richer flavor. 4. Chocolate malt – roasted to a dark brown, imparting nutty and toasted flavors while retaining some sweetness. 5. Black patent malt – carbonized to develop coffee and bitter notes. 41 © 2024 Rolenz Derick Cruz Ingredients of Beer 2. Hops – The primary flavoring ingredient, adding bitterness, tannin, and aroma to beer. – Brewers often use multiple hop varieties to achieve the desired balance of bitterness and aroma. 42 © 2024 Rolenz Derick Cruz Ingredients of Beer 3. Yeast ▪ Saccharomyces cerevisiae – Warmer fermentation temperatures (15-24°C). – Ale, which has a fruitier flavor profile and creamy, soft carbonation. ▪ Saccharomyces pastorianus (formerly S. carlsbergensis) – Cooler fermentation temperatures (7-13°C). – Lager, characterized by a crisp, clean taste and more effervescent carbonation. 43 © 2024 Rolenz Derick Cruz Ales vs Lagers 44 © 2024 Rolenz Derick Cruz Ingredients of Beer 4. Water – Mineral content affects the final taste of the beer. ▪ Soft water – results in a softer mouthfeel, commonly used for lagers. ▪ Hard water – contributes to a fuller body in ales. – The source and mineral content of water are often emphasized as a key characteristic of a brewery’s product. 45 © 2024 Rolenz Derick Cruz Ingredients of Beer 5. Adjuncts ▪ Wheat – added to malted barley, malted before use; alters flavor and color of the beer. ▪ Rice and corn: – Cheaper than barley. – Provide a neutral flavor. – Supply additional starch for sugar conversion, lightening the flavor profile while achieving the desired alcohol content. 46 © 2024 Rolenz Derick Cruz Beer-making 1. Converting – This is the malting process. 2. Extracting – Process to get the sugars into water. ▪ Malt is ground into grist. ▪ Grist and water are combined in a mash tun that will stir the mix. ▪ Proper temperature and agitation convert the starches in the grist into fermentable sugars through enzymatic action (primarily by diastase). 47 © 2024 Rolenz Derick Cruz Beer-making 3. Boiling – After mashing, the liquid, now called wort, is separated from the grain husks and boiled. – Boiling deactivates the enzymes and helps to precipitate proteins and other impurities that could cloud the beer. – The first batch of hops is added during the boil to impart bitterness to balance the sweetness of the malt. 48 © 2024 Rolenz Derick Cruz Beer-making 4. Fermenting – The hot wort is cooled to a suitable fermentation temperature before yeast is added. ▪ Fermenting ale will take 3 to 7 days at warm temperatures. ▪ Fermenting lager will take 14 days at lower temperatures. – A second batch of hops is added later in the fermentation process to enhance aroma. 49 © 2024 Rolenz Derick Cruz Beer-making 5. Conditioning – Ales are typically conditioned for a shorter period, usually a few days to a week, allowing carbonation to develop and residual yeast to settle. – Lagers undergo a longer conditioning period, often 2 to 4 weeks, at very low temperatures (around 0°C). 50 © 2024 Rolenz Derick Cruz  Beer-making Five Major Steps: 1. Converting 2. Extracting 3. Boiling 4. Fermenting 5. Conditioning 51 VIDEO: How Craft Beer is Made © 2024 Rolenz Derick Cruz Distillates 1. Brandy 2. Whiskey 3. Vodka 4. Gin 5. Rum 6. Tequila 52 © 2024 Rolenz Derick Cruz Brandy The name comes from the Dutch word "brandewijn," meaning “burnt wine.” Brandy is a spirit distilled from fruit wine or fermented fruit juice. The Dutch initially used distillation to concentrate the wine and make it easier to transport, discovering that they enjoyed the resulting spirit. Includes varieties such as Cognac and Armagnac, which are specific types of brandy made in designated regions of France. 53 © 2024 Rolenz Derick Cruz Whiskey The name derives from the Gaelic words "uisce beatha" or "usquebaugh," meaning “water of life.” Made primarily from grains: ▪ Malt whiskey – made from malted barley, e.g., Irish Whiskey. ▪ Blended whiskey – a blend of malt whiskey and grain whiskey, e.g., Scotch, Canadian Whiskey. ▪ Straight whiskey – must contain at least 51% of one grain; includes types like Bourbon (primarily corn) and Rye Whiskey (primarily rye). 54 © 2024 Rolenz Derick Cruz Vodka Typically made from fermented grains (such as sorghum, corn, rice, rye, or wheat) but can also be made from potatoes, fruits, or sugar. Often neutral in flavor, but may be flavored with herbs, citrus fruits, berries, vanilla, coffee, or chocolate. Can be as high as 95% alcohol by volume (ABV), though commercial vodkas usually have a lower ABV. 55 © 2024 Rolenz Derick Cruz Gin Often considered a flavored vodka, gin is characterized by its primary flavoring from juniper berries. Besides juniper, gin may include a variety of botanicals such as citrus peel, angelica root, cassia bark, coriander, fennel, and caraway seeds, which contribute to its distinctive flavor profile. 56 © 2024 Rolenz Derick Cruz Rum Made from fermenting sugarcane juice, molasses, or other by- products of sugar refining. The flavor and style of rum can vary greatly depending on the region of production, such as: ▪ light rums from Puerto Rico ▪ dark rums from Jamaica 57 © 2024 Rolenz Derick Cruz Tequila A Mexican spirit made from the blue agave plant, specifically from the region around the city of Tequila in Mexico. Typically distilled twice, which strengthens the alcohol content to about 55% ABV (though final products are usually diluted to lower ABVs). Types of tequila: ▪ Blanco (unaged) ▪ Reposado (aged 2-12 months) ▪ Añejo (aged over 1 year) 58 © 2024 Rolenz Derick Cruz Filipino Alcoholic Beverages 1. Tapuy 2. Basi 3. Tuba 4. Lambanog 5. Sabu 6. Bignay wine 59 © 2024 Rolenz Derick Cruz Tapuy (or Tapey, Tapuey) Tapuy is a traditional rice wine made from fermented glutinous rice. Tapuy typically has a sweet and slightly fruity flavor, with an alcohol content ranging from 7-12% ABV. The fermentation of tapuy involves the use of a starter culture known as “bubod,” which contains both mold (Aspergillus oryzae) and yeast (Saccharomyces spp.). ▪ The mold helps convert the starches in the rice into fermentable sugars. ▪ The yeast ferments these sugars into alcohol. 60 © 2024 Rolenz Derick Cruz Basi Basi is a traditional sugarcane wine from the Ilocos Region, known for its deep cultural roots. Basi can range from sweet to dry and typically has an alcohol content of 8-12% ABV. The fermentation of basi involves yeast (S. cerevisiae) and LAB (Lactobacillus spp.). ▪ Yeast ferments the sugarcane juice into alcohol. ▪ LAB can contribute to the development of complex flavors. 61 © 2024 Rolenz Derick Cruz Tuba Tuba is a mildly alcoholic beverage made from the sap of the coconut tree, often consumed fresh or fermented. Tuba has a sweet and slightly tangy flavor, with an alcohol content of 3- 5% ABV. Natural fermentation involves wild yeasts and lactic acid bacteria. – These microorganisms convert the sap into a mildly alcoholic beverage. – The fermentation process is often spontaneous and can vary based on local conditions. 62 © 2024 Rolenz Derick Cruz Lambanog Lambanog is a potent spirit made from the sap of the coconut tree, known for its high alcohol content. Lambanog has a strong flavor, with alcohol content ranging from 40-80% ABV. It can be enjoyed straight or mixed into cocktails. The initial fermentation of lambanog involves wild yeasts and possibly some LAB, which ferment the sap into alcohol. After primary fermentation, the sap is distilled to increase alcohol content and purity. 63 © 2024 Rolenz Derick Cruz Sabu (or Sabu Wine) Sabu is a fruit wine made from various local fruits, such as mangoes or pineapples, in the Visayas region. Sabu wine has a fruity flavor, with an alcohol content usually around 5- 10% ABV. Yeasts (S. cerevisiae) and sometimes additional wild yeasts are used to ferment the fruit juice. LAB may also be present, contributing to flavor complexity. 64 © 2024 Rolenz Derick Cruz Bignay Wine Bignay wine is made from the fruit of the bignay tree, known for its unique taste. Bignay wine has a distinct fruity and slightly tangy flavor, with an alcohol content typically ranging from 8-12% ABV. Yeasts (Saccharomyces spp.) are used for fermentation. Sometimes LAB are involved in developing flavor profiles 65 © 2024 Rolenz Derick Cruz Overview Lesson 4 Alcohol Fermentation 1. Alcohol 2. Alcohol Fermentation 3. Wine & Wine-making 4. Factors Affecting Yeast Growth 5. Spoilage of Fruit Wines & its Prevention 6. Beer & Beer-making 7. Distillates (BWVGRT) 8. Filipino Alcoholic Beverages 66 © 2024 Rolenz Derick Cruz That’s all. Thank you for listening! ROLENZ DERICK R. CRUZ Food Technology Department BU College of Industrial Technology 67 © 2024 Rolenz Derick Cruz