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Objectives. After reading this chapter, you should be able to display an understanding of how both red and white table wines are produced. describe how sparkling wine is produced. explain how dessert wines are produced. . Introduction.

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    1. Objectives • After reading this chapter, you should be able to • display an understanding of how both red and white table wines are produced. • describe how sparkling wine is produced. • explain how dessert wines are produced. © 2007 Thomson Delmar Learning. All Rights Reserved.

    2. Introduction • Great wines begin in the vineyard, but they are finished at the winery. • Like a chef, the winemaker works with flavors and aromas to create a wine that consumers will enjoy. • The decisions the winemaker makes may appear random in nature, but in reality they are based on a scientific understanding of the techniques used to produce wine. © 2007 Thomson Delmar Learning. All Rights Reserved.

    3. Introduction (continued) • Complicating the winemaker’s quest to create great wine is the fact that people have different tastes and preferences, and there is no one “ideal” style wine. • During the 6,000-year history of wine-making, its production has evolved into a number of complex procedures that produce a variety of wines. © 2007 Thomson Delmar Learning. All Rights Reserved.

    4. Introduction (continued) • Table wine is a wine designed to accompany food. It is produced in numerous forms, both red and white. • It is the most common type of wine consumed in the United States, making up over 90 percent of the market. • A table wine is a still wine (a wine without effervescence). • A table wine is also relatively dry (without sweetness). • It has a moderate alcohol content of about 11 to 15 percent. © 2007 Thomson Delmar Learning. All Rights Reserved.

    5. Introduction (continued) • In the United States, a wine must be less than 14 percent alcohol to be labeled a “table wine.” • This number was chosen for reasons of tax collection, not the true definition of being a wine made to complement food. • Grapes are usually picked at 22 to 25 degrees Brix (°B) to obtain this alcohol level. • Brix is equal to the percentage of sugar by weight. © 2007 Thomson Delmar Learning. All Rights Reserved.

    6. The Process of Fermentation • Fermentation is the process of yeast, unicellular (one-celled) fungi, converting the sugar in grape juice to alcohol and carbon dioxide. • Other microorganisms can do this, but yeast ferment with the most efficiency and can survive in the higher alcohol at the end of fermentation. © 2007 Thomson Delmar Learning. All Rights Reserved.

    7. The Process of Fermentation • The species of yeast that is best suited for winemaking is called Saccharomyces cerevisiae. • The name Saccharomyces is derived from the Latin sugar-fungus; cerevisiae refers to grain. • Saccharomyces cerevisiae’s most common use is in bread making. © 2007 Thomson Delmar Learning. All Rights Reserved.

    8. The Process of Fermentation • The rate of fermentation is affected by a number of factors, including • temperature—the warmer the juice is, the faster it will ferment. • However, above 100°F, yeast will die off. • acidity—the higher the concentration of acid (the lower the pH), the slower the rate of fermentation. © 2007 Thomson Delmar Learning. All Rights Reserved.

    9. The Process of Fermentation(continued) • nutrients—if the juice is low in nutrients, the yeast may not be able to ferment to dryness. • alcohol—at higher concentrations, 13 percent to 16 percent depending on strain, yeast begin to die. • sugar—although sugar is required for yeast growth, if the sugar concentration is greater than 30 percent, it inhibits yeast growth. © 2007 Thomson Delmar Learning. All Rights Reserved.

    10. Natural Fermentation • Wine was made for thousands of years before there was knowledge of such things as microscopic organisms called yeast. • Although early winemakers did not understand the mechanism, they knew how to use it to produce wine. • Some wineries use natural or “wild” yeast that live on the grape skins to make wine. © 2007 Thomson Delmar Learning. All Rights Reserved.

    11. Natural Fermentation (continued) • “Wild” yeast can give the wine more complexity, but there also is a higher risk of off-flavors or incomplete fermentation. • Today most winemakers use commercially available strains of yeast. • These yeasts are similar appearance to baker’s yeast, and they give the winemaker a clean, efficient fermentation. © 2007 Thomson Delmar Learning. All Rights Reserved.

    12. Harvest • Grapes must be harvested and processed as soon as they reach their peak of flavor. • The weather conditions set the pace of harvest. • Once the grower and the winemaker have determined that the grapes have reached their optimum ripeness and flavor, they are picked and brought to the winery. • At the winery the crop is weighed, inspected, and analyzed before being processed. © 2007 Thomson Delmar Learning. All Rights Reserved.

    13. Red Wine Crush and Fermentation • After the grapes are weighed and inspected, they are brought to the receiving hopper and unloaded. • At the bottom of the hopper, there is either a screw or a belt conveyor that is used to transport the fruit to the stemmer-crusher. © 2007 Thomson Delmar Learning. All Rights Reserved.

    14. Red Wine Crush and Fermentation(continued) • The stemmer-crusher has two functions: first it takes the berries off the stems, and second it breaks the berries open to release the juice. • The stemmer portion separates the berries from the stems. • The crusher breaks open the berries and releases the juice. © 2007 Thomson Delmar Learning. All Rights Reserved.

    15. Red Wine Crush and Fermentation(continued) • The mixture of approximately 80 percent juice, 16 percent skins, and 4 percent seeds produced by the crusher is called must. • At this point, the must is liquid enough to be pumped to a tank for fermentation. • In modern wineries, fermentation tanks are usually made of stainless steel, although vats made of wood or concrete are also still in use. © 2007 Thomson Delmar Learning. All Rights Reserved.

    16. Red Wine Crush and Fermentation(continued) • After the tank is loaded, the must is analyzed and adjusted if necessary. • The compounds that are added to adjust the must are natural and already present in the must to some degree, such as sugar, acid, nutrients, and yeast. • The exception to this is the preservative sulfur dioxide. © 2007 Thomson Delmar Learning. All Rights Reserved.

    17. Red Wine Crush and Fermentation(continued) • Additives to wine are regulated and vary from region to region. • For example, it is legal to add sugar to must in France but not acid, whereas in California the opposite is true. © 2007 Thomson Delmar Learning. All Rights Reserved.

    18. Red Wine Crush and Fermentation(continued) • Once the fermentation begins, the carbon dioxide that is evolved causes the skins to float to the top of the tank and form a cap. • The juice from most red wine varieties is clear, so it is necessary to extract the red color out of the skins to make red wine. • If the skins are in a cap that is floating above the juice, very little extraction will take place. © 2007 Thomson Delmar Learning. All Rights Reserved.

    19. Methods of Cap Management • To combat extraction problems, the cap is mixed into the juice several times a day. • The manner in which it is mixed, and the frequency, have a major effect on the overall style of the wine being made. • Punching down is the oldest, simplest method of mixing the cap of skins and the juice. A punch-down device is used to press down the cap into the juice. © 2007 Thomson Delmar Learning. All Rights Reserved.

    20. Methods of Cap Management(continued) • Pumping over is where juice is irrigated over the top of the cap. • As the juice percolates through the skins, it extracts the color and flavor. • Rotary fermentors are the most modern and least labor-intensive method. • They are large horizontal tanks that are rotated and so the cap is rolled over into the juice. © 2007 Thomson Delmar Learning. All Rights Reserved.

    21. Methods of Cap Management(continued) • Carbonic maceration is where a portion or all of the grapes are not crushed but loaded into the tank as whole clusters. • As the fermentation in the juice progresses, it also begins to take place within the cells of the intact grape berries. • This produces soft tannins and a unique strawberry or bubble gum aroma. © 2007 Thomson Delmar Learning. All Rights Reserved.

    22. Methods of Cap Management(continued) • Extended maceration is more suited to big-bodied red wines such as Cabernet Sauvignon. • In this technique, at the end of fermentation the must is not pressed, and the skins are left in contact with the young wine from 1 to 8 weeks. • This method is used to give big-bodied wines less tannins. © 2007 Thomson Delmar Learning. All Rights Reserved.

    23. Red Fermentation • Red wines ferment at 75° to 90°F; at this temperature, there is optimal extraction of color without harming the yeast. • Fermentation usually takes from 1 to 3 weeks at this temperature. © 2007 Thomson Delmar Learning. All Rights Reserved.

    24. Pressing the Skins • In red wines, when fermentation is complete and the winemaker is satisfied with the flavor extraction, it is time to separate the wine from the skins. • The majority of the wine is simply drained out of the tank by gravity; however, 10 to 20 percent is held within the skins still inside the tank. © 2007 Thomson Delmar Learning. All Rights Reserved.

    25. Pressing the Skins (continued) • The skins are then removed from the tank and loaded into a press, which squeezes out their remaining liquid. • There are a number of types of presses, but they all work in the same manner. • Force is applied to a layer of skins against a screened or slatted surface that allows the juice through but holds the skins and seeds back. © 2007 Thomson Delmar Learning. All Rights Reserved.

    26. Types of Presses • The basket press is the oldest and most simple design. • It is a vertical cylinder made of slats of wood arranged with small gaps in between them. • Traditional basket presses are gentle but require the cake to be broken up by hand in between press cycles. © 2007 Thomson Delmar Learning. All Rights Reserved.

    27. Types of Presses (continued) • Tank presses are cylindrical steel tanks that are 3 to 8 feet in diameter and are mounted horizontally. • On one side of the interior, there is an inflatable bag or membrane, and on the other side is a series of perforated screens or channels. • The bag inflates squeezing the skins against the screens to remove the juice. © 2007 Thomson Delmar Learning. All Rights Reserved.

    28. Press Fractions • Free run is the first wine to come off during pressing and it is the highest-quality juice. • Press fraction—As the cycles of pressing go on, the quality of the juice diminishes becoming more astringent and bitter. • The young wine is then collected in a sump at the base of the press before being pumped into a receiving tank. • After the skins dry, they are called pomace. © 2007 Thomson Delmar Learning. All Rights Reserved.

    29. Settling and Racking • Yield after fermentation is typically about 170 gallons of wine per ton of grapes. • After pressing, the wine is pumped to a tank in the winery cellar for storage. • At this point the new wine is very turbid and full of suspended solids such as yeast cells, particles of grape skins, and pulp. © 2007 Thomson Delmar Learning. All Rights Reserved.

    30. Settling and Racking (continued) • After several days, the suspended solids begin to settle out to the bottom of the tank forming a layer of thick mud-like material called lees. • After a week or two the clean wine is decanted off the layer of lees in a process called racking. © 2007 Thomson Delmar Learning. All Rights Reserved.

    31. White Wine Crush and Fermentation • White wines are made from white (green skinned) grape varieties. • Because the juice of most red grapes is colorless, it is also possible to make a white wine from red grapes as is done with White Zinfandel and Blanc de Noir sparkling wine. • Red wines receive most of their flavor from the skins, and whites get theirs from the juice. © 2007 Thomson Delmar Learning. All Rights Reserved.

    32. White Wine Crush and Fermentation(continued) • The most important difference in processing is that red wines are pressed after fermentation and white wines are pressed before. • White are usually picked early in the morning and brought to the winery while they are still cool to preserve the fresh fruit flavors. © 2007 Thomson Delmar Learning. All Rights Reserved.

    33. White Wine Crush and Fermentation(continued) • In white winemaking, the grapes are picked, weighed, inspected, and unloaded into the receiving hopper much in the same way they are for red wine production. • After they are picked, red and white winemaking techniques diverge and the juice must be separated from the grapes. © 2007 Thomson Delmar Learning. All Rights Reserved.

    34. White Wine Crush and Fermentation(continued) • The fruit can be • crushed and pressed. • This is similar to the way red grapes are handled except the pressing takes place prior to fermentation. • crushed, dejuiced, and pressed. • Here the juice is drained out by gravity between crushing and pressing. • whole cluster pressed. • Uncrushed clusters are pressed directly—the most gentle method. © 2007 Thomson Delmar Learning. All Rights Reserved.

    35. White Wine Fermentation • After pressing, the juice is pumped to a settling tank. • The juice is kept cool, at around 50°F, and held in the settling tank for 12 to 72 hours to allow the lees to form. • The juice is racked off the grape solids, or primary lees, to avoid the production of undesirable flavors during fermentation. • In the fermentation tank, yeast and fermentation additives are added. © 2007 Thomson Delmar Learning. All Rights Reserved.

    36. White Wine Fermentation(continued) • White wine fermentations take place at a cool temperature, 45° to 60°F, to help retain its fruity aromas. • White fermentations take two to three times as long as red fermentations, about 3 to 6 weeks. • After fermentation, the new wine is racked off the yeast lees. © 2007 Thomson Delmar Learning. All Rights Reserved.

    37. Barrel Fermentation • Barrel fermentation of white wine gives it a distinctly toasty aroma and is very popular with Chardonnay. • After the fermentation is finished, the barrels are topped off and the wine is left in contact with the yeast lees at the bottom of the barrel. • This technique of aging is called sur lie (French for “on the lees”). © 2007 Thomson Delmar Learning. All Rights Reserved.

    38. Barrel Fermentation (continued) • Sur lie aging: • This gives the wine more of a yeasty-bready aroma and more viscosity. • The young wine can be left sur lies for many months; sometimes the yeast is periodically stirred to intensify the character. © 2007 Thomson Delmar Learning. All Rights Reserved.

    39. Malolactic Fermentation • The most prevalent acids in wine are tartaric acid and malic acid. • Malolactic bacteria convert malic acid in wine into lactic acid. • Malolactic fermentation has several effects on the wine, • De-acidification, malic acid is a stronger acid than lactic • Microbial stability, if malo-lactic finishes during aging it will not spoil the wine by taking place in the bottle. • Malolactic fermentation produces a compound called diacetyl that has a distinct buttery character. © 2007 Thomson Delmar Learning. All Rights Reserved.

    40. Malolactic Fermentation (continued) • Malolactic fermentation usually takes place after the primary, or alcoholic, fermentation and occurs at a much slower pace. • Malolactic fermentation is usually encouraged in red wines for reasons of stability. • With white wines, it is a stylistic concern. • In a light-bodied fruity wine like Riesling, it is usually avoided, while in a rich oak-aged Chardonnay it would be more appropriate. © 2007 Thomson Delmar Learning. All Rights Reserved.

    41. Barrels and Aging • The first to store wine in barrels were the Romans. • Winemakers soon discovered that storing wine in barrels had positive effects on the wine’s flavor. • Barrel makers are called coopers. • There are two types of reactions that are taking place during aging: • The wine undergoes a slow oxidation. • Flavor components are absorbed from the wood. © 2007 Thomson Delmar Learning. All Rights Reserved.

    42. Barrels and Aging (continued) • Oak is the chosen wood for wine barrel production. • It is strong and durable; it is also nonporous, so the barrels will not leak. • It also has excellent flavor and aroma compounds that are extracted into the wine. © 2007 Thomson Delmar Learning. All Rights Reserved.

    43. Barrels and Aging (continued) • The two major categories of oak are European and American. • There are two species of European oak that are used for making wine barrels, Ouercus sessilis and Quercus robar; they are grown throughout France and central Europe. • European oak is known for giving wine a rich, toasty vanilla aroma. © 2007 Thomson Delmar Learning. All Rights Reserved.

    44. Barrels and Aging (continued) • In America Quercus alba, or white oak, is used for barrel making and has stronger, more woody flavors than European oak. • Beyond the type of oak used, a barrel’s flavor varies depending on the forest the wood is from and the various methods of production that different coopers use. © 2007 Thomson Delmar Learning. All Rights Reserved.

    45. Barrels and Aging (continued) • Much of the flavor obtained from aging wine in barrels comes from what is extracted out of the oak; however, the softening of the wine’s texture that comes with aging is due to the process of slow oxidation. • Oak has the quality of being semipermeable to oxygen allowing a small amount of oxygen to be incorporated in an aging wine. • This helps tannin molecules to polymerize and settle out, softening a wine's body and making it less bitter. © 2007 Thomson Delmar Learning. All Rights Reserved.

    46. Barrels and Aging (continued) • During aging, a small amount of alcohol and water in the wine can evaporate through the oak of the barrel. • This evaporation causes the remaining wine in the barrel to become more concentrated with acid and flavor. • From time to time, the ullage (headspace in the barrel) that is produced by this evaporation must be displaced by topping the barrel up with wine from the same lot. © 2007 Thomson Delmar Learning. All Rights Reserved.

    47. Finishing a Wine • After aging is complete, the wine is pumped out of the barrel and sent to the tank cellar for preparation for bottling. • Wines can be bottled from a single fermentation lot, but more often different lots are blended together. © 2007 Thomson Delmar Learning. All Rights Reserved.

    48. Finishing a Wine (continued) • After the blend is selected, two more steps must be completed before wine is ready to be bottled: • Clarification produces a wine that is brilliant and free of suspended solids. • Stability operations are performed to ensure that a brilliant wine stays so. © 2007 Thomson Delmar Learning. All Rights Reserved.

    49. Clarification and Fining • The simplest and most gentle form of clarification is settling and racking. • Fining is the process of adding a compound called a fining agent to the wine that will react with compounds in the wine causing them settle out. • After the wine settles, the fining agent and the wine component that it removed are left behind in the lees when the wine is racked. © 2007 Thomson Delmar Learning. All Rights Reserved.