|The juice from grapes ferments naturally into wine, and no doubt wine was drunk by man before the beginning of recorded history. In the United States during the last decade, winemaking has become a popular hobby.
Uses, Classification, and Nomenclature
|Uses of Wine
Wine is a product of nature. If one crushes some grapes in a container the wild yeasts present on the skin will turn juice into wine of varying quality. The winemaker or enologist uses his scientific ability to help nature produce excellent wines.
Wine has many uses. It is used to complement meals, and in countries where wine is cheap it is served as the normal beverage at mealtime. Wine is also used to improve the flavor of food in cooking. Throughout history it has played an important role in religious ceremonies, and is used to minister to the ill. Wine is also commonly used for the celebration of important occasions, and to welcome quests.
Wines can be classified in several ways. One methods is based on characteristics that are easily recognized such as color, presence of herbs or flavoring material, amount of carbon dioxide and sugar present, and detection of varietal aromas (Amerine and Singlwton, 1965). Geographical origin, or the use to which the wine is to be put are other classification criteria.
|In the United States there are five main classes of wine based on use (Anonymous, 1975). They are listed in Table 20-1 along with some of the best known wine types in each class.
|Appetizer wines are best enjoyed before meals. Sherry and vermouth are the main appetizer wines and may be sweet or dry. Sherry made by baking develops a nutty flavor. When made by the flor process, a creamy scum that gives the sherry a special flavor develops in the presence of air. Wines made without flor are called olorosos and are of an entire different character.
Vermouths are wines that have been flavored with various herbs. Seeds, leaves, flowers, and bark of various plants are used. Vermouth contain 15-20 percent alcohol.
Special and natural wines are made by adding pure, natural flavors to the wine. For example, the retsina wine of Greece is made by adding resin to white wine during fermentation.
Red dinner (table) wines are used to accompany main course dishes, and are usually dry (most or all of the sugar fermented out) with alcohol content ranging from 10.5-14 percent. Some of these wines contain sufficient tannin to produce an astringent (puckery) flavor. Most red table wines belong to the Burgundy or Claret types (Table 20-1). Burgundy wines have a pronounced flavor, body, bouquet, and a deep-red color. Clarets are ruby-red wines and are tart and light or medium-bodied. In California, wines and are tart types often bear the name of the grape from which they are made and each has its own distinctive character.
Rosé wines are pink, and contain 10-14 percent alcohol.
White dinner (table) wines vary from dry to sweet. They are usually pale-straw to deep-gold in color, and their alcohol content varies from 10 to 14 percent. The production of white table wine differs from that of red wine in that the former is fermented from the juice only, without the skins. White wines mature quicker than red wines and can be bottled earlier; some attain their optimum quality within a year after bottling.
The most popular white wines are Sauterne, Chablis, and Rhine wine, and most other white wines resemble one of these types. Sauternes range from dry to sweet, and in France are traditionally a blend of Sémillon, Sauvignon blanc, and Muscadelle de Bordelais. In the United States many white grape varieties are used, and wines are usually named for the grapes from which they are made.
Chablis has a pale gold color and a delicate flavor. The wine is made from several varieties of white wine grapes, and is often named after the grape from which it is made.
Rhine wine designates a light-bodied, golden or slightly green-golden wine, ranging from tart to semisweet in flavor. Traditionally Johannisberg Riesling has been the chief variety used, but in the United States many other grapes are also used. The wine is usually packaged in tall, tapered bottles (fig. 20-1). Moselle and Hock also designate Rhine wines; the latter name is used in Australia and England.
Light Muscat (sweet white wine) has a distinct Muscat flavor and aroma, and is sometimes named after the grape variety from which it is made. The wine may vary from dry to very sweet.
Delaware, Catawba, Elvira, Dutchess, Steuben, and several other varieties grown in the Midwestern and eastern part of the United States can be used to make excellent white wines with distinctive flavors and aromas. Delaware and Elvira are fruity and tart, and Catawba may be dry or semisweet.
Dessert wines are full-bodied, usually sweet wines that are served at the end of the meal. Most of these wines are fortified with brandy, contain around 18 percent alcohol, and are medium-sweet to sweet and red to pale gold. Popular types include muscatel, port, Tokay, and cream sherry.
Muscatel is a sweet wine made from Muscat grapes, with a distinct Muscat flavor and aroma. Although Muscat of Alexandria is used to make most of the muscatels, several other varieties, such as Muscat Frontignan (Muscat Canelli), are also used. The solor of the wine varies from golden or dark amber to red.
|Fig. 20-1. Many wine bottles have traditional shapes, depending on the wine type. Four examples are shown above.
|Red Muscatel (Black Muscatel) is a red wine made from Black Muscat (Muscat Hamburg) grapes.
Port wine originated in Portugal and is usually a heavy-bodied red, fruity wine. Most ports are a deep red, but there is also a straw-colored tawny port. Many grape varieties can be used to make port (Table 20-1).
Tokay is a blend of dessert wines, usually angelica, port, and sherry. The Tokay wine of California should not be confused with the Hungarian Tokay wines or with the Tokay grape of California. Tokay has flavor similar to sherry.
Kosher wines are those certified by a rabbi. Although they may be of any type, the largest production is a sweet red wine made mainly in the eastern United States from the Concord variety.
Champagne can be made from several grape varieties (Table 20-1), although the traditional ones are Chardonnay, Pinot blanc, or Pinot noir. The driest champagne is termed "nature": the very dry "brut": the semidry "extra-dry," "sec," or "demi-sec"; and the sweet is often labeled 'doux" (Anonymous, 1975). Champagne is also made from Emerald Riesling, Burger, Folle blanche, Green Hungarian, French Colombard, Saint Émilion, Sauvignon vert, Delaware, Catawba, Elvire, and other varieties.
Carbonated wines are made from white or red wines (both dry and sweet) by using artificial carbonation to make them more effervescent. They cannot be labeled champagne, sparkling burgundy, or Cold Duck.
Sparkling Muscat is made from light Muscat wines. It is also referred to as Muscato Spumante. Sparkling Rosé, made from grapes used for Rosé dinner wines, is pink and is similar in flavor to pink champagne. Crackling wines are less effervescent than champagne. In the United States they must be made by a natural second fermentation in a bottle or other container.
Brandy is distilled, fermented grape juice. In the United States only pure distillate of grape wine can be called brandy. The usual types are a straight brandy and one containing sweetening and/or flavoring substances. Two special types are distilled, one from Muscat wines, and a strong-flavored brandy from pomace (crushed grapes after the extraction of juice), called "grappa".
Many semigeneric names of wines arose from names of famous Old World viticultural districts; Burgundy, Rhine wine, Sauterne, and Bordeaux are examples. As these wine types become known worldwide, the same names were applied to wines having similar characteristics. For example, early winemakers in United States named many wines after similar ones in their country of origin. Claret was the name given by the English to the light-red wine from Bordeaux, and subsequently, similar wines were known by the same name.
Varietal wines are named for the grapes from which they are made. In California at least 51 percent of a varietal wine must be produced from the grape for which the wine is named. The wine should also have the characteristics taste and aroma of the grape. Some brands of wine are labeled only with a class name (e.g., white dinner wine).
There is also a legal difference among wines. Dinner wines must not contain more than 14 percent alcohol. These are also sometimes referred to as dry wines or light wines. Dessert wines have an alcohol content of 18-21 percent, and sherries contain 17-21 percent.
Some wineries use proprietary names that may not be used by any other winery.
|How to Make Home Wine
Besides being an enjoyable pursuit, winemaking can also save a considerable amount of money for home winemaker. Making wine at home is legal up to 200 gal (757.1 liters) per year for the personal consumption of the family. The winemaker must, however, be the head of the household, and the wine cannot be sold.
|Basis for Winemaking
The most important process in winemaking is the fermentation (webb, 1974), which converts the grape-berry sugars into alcohol and carbon dioxide gas by a series of biochemical reaction. Microscopic one-called plants called yeast are required for the chemical changes, as the yeasts produce enzymes that are necessary for the reactions (Fig. 20-2). Although many yeasts are collected on the bloom or waxy coating of grape berries and can serve as the fermenting organisms, winemakers use a special yeast for fermentation.
|Fig. 20-2. Yeast cells (Saccharomyces species) reproduced by budding. These microscopic plants convert sugar into alcohol.
|Some procedures used in all wine production (Amerine and Marsh, 1962) are listed below:
1.Crush the fruit to produce juice.
Although the juice of almost any fruit can be fermented into a winelike beverage, the grape is the most suitable. Select clean, fresh fruit that is not overripe: avoid moldy, injured, or rotting fruit. For California grapes around 22° Brix for dry table wines is best. About 12-15 lb (5.44-6.80 kg) of fruit will make 1 gal of wine.
Red, white, or rosé wines may be made; the type depends on the available grape varieties. Red wines are made from black or red varieties. In most varieties the pigment is located in the skins, although some red grapes also have pigment in the flesh of the grape. However, such color is less permanent than pigment from the skins and tends to deposit brown crusts in the bottles during storage. Pink wines can be made by removing skins and seeds at an early stage in the fermentation of red grapes. White wines are usually produced from white grapes; they can also be made from red varieties, if the flesh is not red and skins are removed early.
Wines can also be made from many other fruits. Dried fruits such as raisins, prunes, and figs assume a rather unattractive brown color, but make interesting wines. Honey is a concentrate that produces an acceptable wine and is used in the production of mead.
Several essential and/or useful items in home winemaking include small crushers and presses, and other equipment that can be obtained in hardware stores or from mail-order firms.
For small quantities of grapes, fruit can be crushed by hand or by pounding with a wooden mallet in a tub. If frozen fruits are to be used crushing is not necessary, because juice readily flows from such fruit when melted. Iron, copper, or galvanized pails, screens, or tubs should not be used.
Grapes that have been fermented on skins for several days before pressing are much easier to press than freshly crushed grapes. Sine red grapes are pressed undergoing fermentation, and white grapes are pressed before fermentation; the former yields about 20 percent more wine per ton fresh grapes (Amerine and Marsh, 1962)
|Fig. 20-3. A roller-type crusher in which a crank turns wooden or aluminum rollers. Grapes are dropped into hopper at the top, and stems are caught by screen below the crusher.
||Fig. 20-4. A baskets press is suitable for pressing grapes. A ratchet lever system is used to press a plate against the grapes below, and juice comes out through vertical spaces in the barrel.
|Containers for Fermentation. Stone, glass, plastic, or wooden containers may be used. Wood is excellent for use with amounts of must greater than 10 gal (37.9 liters) but is not recommended for smaller sizes. Plastic garbage cans or plastic laundry baskets make excellent containers for winemaking and are easy to clean. Plastic containers are also much lighter and easier to handle than crocks or wooden containers. Glass carboys are also useful.
Hydrometer to Measure Sugar. Except for California grapes, most fruits require the addition of sugar and/or acid. A glass or clear plastic cylinder and a hydrometer are necessary to measure sugar content (Fig. 14-1). The higher the sugar content, the higher the bulb will float in the juice or fermenting wine. A reading of 22°-24° Brix will result in wines containing about 12 percent alcohol (Amerine and Marsh, 1962). About 1¼ lb(0.113 kg) of sugar must be added per 10 gal (37.9 liters) of juice and skins for each degree the hydrometer scale registers below 23° Brix.
Fig. 20-5. Two pieces of wood, hinged together, can be used to press out juice from grapes enclosed in a cheesecloth bag by squeezing the boards together
|Fig. 20-6. Siphoning can be used to transfer wine from one container to another without disturbing the sediment. Hoses can be made of plastic, rubber, or glass.
|It is best not to add the sugar before the start of fermentation. When fermentation is proceeding actively, add about one-fourth of the required sugar to a small portion of the liquid, let dissolve, and then add it to the fermentation containers. The other three one-quarter portions can be added at daily intervals.
Siphon. A siphon tube is needed to transfer wine from one container to another. A plastic or rubber hose about 6 ft. (1.83 m) long with a ½ in. (12.7 mm) inner diameter is satisfactory. The purpose of siphoning from one container to another is to get rid of sediments that have settled out of the wine (Fig. 20-6). The outlet end must be lower than the inlet end.
Containers for Storage. Glass bottles or carboys and plastic containers are recommended for storage containers. Glass bottles should range from 1 to 4 gal (3.79-53.0 liters) and more; 5 gal (15.1 liters) bottles are a convenient and available size. White wines are best kept in glass or plastic, while red wines can develop better when stored in wood for 1-3 years in a cool place. However, wood has several disadvantages: evaporation, leakage, possible woody flavored wine, and difficulty of cleaning
Corks and Bottles. One can buy a small hand-corking machine from a wine supply house. Bottles must be thoroughly cleaned before use, and should be filled so that only a very small air space is present between the cork and the wine. Too much air discolors white wines and causes off-flavors in red wines. After corking, bottles should be stored on their sides at 55°-60°F (13°-16°C).
Grapes may be bought directly from growers or at markets. First crush grapes in a range of 20-24° Brix, then remove stems and leaves. The crushed grapes may then be placed in the fermentation container, which should not be more than three-fourths full.
One can also add 3 oz (5 level tablespoonsful) of one the metabisulfite salts in 1 qt of warm water (80.4 g per liter). One teaspoon per gallon will give 65 ppm of SO2.
Yeast. Four hours after SO2 has been added, add a special wine yeast. This can be purchased dry, as a liquid, or as a yeast colony on an agar slant. Dry yeast can be added directly to the juice or must.
Four to seven days after fermentation in the primary state, bail the must from the fermenter into a press allowing juice to run into a plastic tub, wooden barrel, or other container. Using a siphon tube, transfer the juice into large bottles or carboys. When the press is filled with pulp, slowly apply pressure so that the juice runs into the tub. Release pressure, stir the pomace, and press again. Repeat this procedure until most of the juice is extracted from the pomace.
When using a wooden barrel as a primary fermenter, elevate it and install a spigot near the bottom. You can then drain off the new wine, leaving the pulp in the barrel. This system leaves little juice for pressing.
|Fig. 20-7. Fermenting juice with a fermentation lock allows CO2 gas to escape, but prevents oxygen from entering the bottle. Arrows show direction of movement of CO2.||Fig. 20-8. Various types of storage racks can be constructed, such as the cardboard wine case and collapsible rack shown here.|
|Wine Stabilization. In the following the grape harvest store the wine at 16-24°F (-9° to -4°C) for two weeks before bottling. The cold wine will then drop any additional solids and clarity for bottling. It can also be held for several months during the summer and then stabilized in a refrigerator, and bottled in August or September. A temperature of 22-24°F (-6° to -4°C) is recommended (Eakin and Ace, 1975).
If the wine is not clear, a clarifying agent such as bentonite or "Sparkolloid" may be used.
These wines are made by the same procedure as red wines except that pressing should be done within 12-24 hr after the must begins to ferment. Visual inspection can indicate when the desired amount of red color is attained.
Since juice does not flow as freely from crushed white grapes as from red grapes, the home winemaker can except only about 100 gal (378.5 liters) of juice per ton of grapes (Amerine and Marsh, 1962). However, a more complete removal of juice can be obtained if about 0.1 g of pectic enzyme is added per gallon (3.79 liters) of fresh crushed grapes and the must is allowed to stand for 2-4 hr before pressing.
Another commercial technique is to ass SO2 to the must and let the free-run juice drain for about 24 hr. Holes or screens in the bottom of a container can be used. The free-run juice makes the best wine, but the skins and seeds can also be pressed and the resulting juice made into a wine of lesser quality.
SO2 and pure yeast culture are added to the juice by the technique described under making red wines.
Immediately after racking there should be 25-30 ppm of SO2 in the wine. SO2 is essential for white wines to prevent oxidation and to keep them from browning. Put the bisulfite into the empty container before adding the wine. The siphon tube should be about half way down in the wine, then gradually lowered as the wine flows out to cause minimum disturbance of the lees at the bottom of the container. The liquid flow can be started by suction. The discharge tube should be in the bottom of the container, as this helps mix SO2 and wine and reduced aeration. One may have to rack several times before the wine is clear. In all racking operations, care should be taken not to disturb the lees which are very light. After 2 or 3 weeks one can rack again and discard the lees.
New white wines stored at 45°-55°F (7°-13°C) clarify best, and are ready for consumption in 6-12 months.
Wine can be stabilized by subjecting it to cold conditions. Stabilization is the process of storing wine at low temperature to precipitate tartrate - the crystals that form in the bottom of the wine bottle and detract from the appearance of the wine.
Bottles should be filled to one-half inch (12.7 mm) from the cork or cap using a siphon hose. After the bottles have stood upright for about a week to allow the corks to dry out and seat, place the bottles on their sides to age (Eakin and Ace, 1975). Capped bottles can be stored upright because no air can pass through the caps and oxidize the wine.
Many white wines are ready for bottling 6-12 months after fermentation. A cool cellar is a good place to store wine, and storage racks are easy to build. (Fig. 20-8).
Concentrated juice may also be used to make an acceptable wine. These are available from wine supply firms. Some wineries also sell concentrates of about 70 percent in 5 gal (18.9 liters) containers should be placed in hot water 1-2 hr so that the contents will pour easily into a fermentation container. Dilute the concentrate by adding about 15 gal of water for each 5 gal of concentrate (57 liters of water per 19 liters of concentrate) while stirring (Amerine and Marsh, 1962). If the reading is above 23° Brix, add water and stir; if it is below 21° Brix, add more concentrate. Follow directions for making white wines (p. 313).
If the wine is flat after fermentation one can add 1½ oz of citric acid for each 10 gal (1.1 g per liter) of wine. Metabisulfite at about ½ oz/10 gal (1g per 2.653 liters or 500 mg per 1.33 liter).
A choice white table wine, usually a few months old, is used to make champagne. Champagne yeast and sugar are added to the wine to induce a second fermentation. Then the wine is placed in securely closed bottles to withstand developing pressure caused by fermentation. The pressure is due to the carbon dioxide gas formed that causes the wine bubbles. Sparkling wines require heavy bottles and thick, wired on corks. The amount of pressure is determined by amount of sugar in the blend (called the cuvee). Workers in champagne cellars sometimes wear wire face masks and gloves for protection in case the pressure should cause a bottle to break.
Bottles of fermenting champagne are placed in horizontal tiers or large boxes from a few months to several years. During this time secondary fermentation occurs. After its completion, the wine ages in the bottles until the flavor and bouquet are at peak quality. Traditionally, the yeast sediment is removed before the mature champagne can be shipped.
Another technique for making champagne is the transfer system. In this operation the contents are disgorged from the bottles under pressure into a tank. The yeast sediment is then removed by filtering the champagne under pressure into a clean bottle, and the dosage is added to the tanks or to bottles before filling.
For sweet dessert wines use grapes at their highest degree Brix, but without raisining. After a dry red or white wine of around 12 percent alcohol has been produced, add 13/5 pints of 90 proof brandy (45 percent alcohol) per gallon of wine (3 liters brandy to 3.75 liters wine). Stir thoroughly, and add sufficient sugar forms, allow it to settle and then rack and bottle.
Another and inexpensive technique is to begin with the method used for fermenting dry table wines. When the must reaches a 5° Brix and the fermentation is proceeding actively, add sufficient grape concentrate or sugar to raise the sugar percent to 10° Brix. When the degree Brix falls to 5°, add more sugar or concentrate. By making three or four such additions, an alcohol content of 16 or 17 percent can be obtained. Add about one ounce (28.4 kg) of potassium metabisulfite per 10 gal (37.9 liters) of wine when the fermentation ceases. Rack the wine several times to get rid of yeasts and other microorganisms.
In California, many winemakers use Mission, Palomino, Thompson Seedless, and Tokay grapes to make sherry. After fermentation of the juice to the desired sugar content, brandy is added to stop fermentation. The new wine is called shermat.
The wine is then baked in lined or stainless steel or concrete tanks, or in redwood containers at 100-140°F (38°-60°C) for 2-4 months. Baking may be performed in a heated room. In tanks heated by coils, or by the heat of the sun. Later the sherry is gradually cooled to cellar temperature and is then aged like other wines. The heating, the oxidation caused by contact of the warm wine air, and the aging in wood barrels combine to result in the pleasant nutty flavor characteristic of California Sherry.
Some California wineries produce a "flor" sherry, using the Spanish method by which a film-yeast growth called flor is allowed to form on the surface of the wine in partially filled containers. The more recently developed "submerged flor" process is used by some wineries. This process also gives the wine a distinctive flavor.
Wines can be made from many kinds of fruit including apples, pears, currants, blackberries, elderberries, raspberries, strawberries, peaches, apricots, plums, cherries, prunes, figs, grapefruit, oranges, bananas, and so on. Nearly all fruit except grapes requires amelioration. Sugar and/or acid must be added.
Select clean, fresh fruit that is not overripe, moldy, or otherwise spoiled; 12-15 lb (5.44-6.80 kg) of most fruits will yield about 1 gal (3.79 liters) of juice. Since many fruit varieties have a stronger flavor than most varieties of grapes, the juice may be diluted with water. As little as 3-5 lb (1.36-2.27 kg) of fruit for each gallon (3.79 liters) of water can be used (Eakin and Ace, 1975).
If no water is to be added, take a hydrometer reading of the juice. If water is added, take a reading following its addition after 5 min of stirring. Degree Brix will be low since the juices of most fruits vary from 5 to 16 percent in sugar content. When water is added, the sugar content of the juice will be low and sugar must then be added.
From 75 to 100 ppm of SO2 must be present in the must. If dilution is desirable, add water from the hot water faucet after the SO2 is added. Much of the yeast and bacteria are killed in the water heater. If the fruit is boiled, SO2 is not required as boiling will kill the undesirable yeast and bacteria. Boiling also releases more of the pectin. Determine the amount of sugar required and add one-half of it to the crushed fruit. Save the rest and add it when the pressed juice is placed in glass carboys for final fermenting (Eakin and Ace, 1975). This procedure may help to prevent a stuck fermentation (wine that has stopped fermenting before all sugar is converted into alcohol).
The requirement of large amounts of sugar, and the fact that the juice may have been diluted with water, reduces the chances for the vigorous growth of yeast. Therefore, addition of yeast nutrient is another preventive measure against the occurrence of a stuck wine.
Many fruits will be low in acid, and one should add tartaric or citric acid powder or acid blends. Low-acid wines will not clear properly, may not ferment completely, will lack a tangy flavor and taste more like flavored water. Some of the high acid fruits will require dilution with one part water to one part juice. A proper acid level for fruit wines is about 0.65 percent.
A pectic enzyme should be added when a fruit wine is produced, especially with pulpy fruits like strawberries, peaches, and plums. The enzyme added to the fresh, crushed fruit will break down the pectin and may result in the greatest possible yield of juice. Another technique is to add the pectic enzyme to the carboy when the juice is pressed from the primary fermenter.
An all-purpose wine yeast may be added 4 hr after the SO2 is added to the must. If hot water is used for dilution, wait until the temperature drops to 75°F (24°C) before adding the yeast.
Fermentation should be performed at 65°-75°F (18°-24°C). The pulpy mass (cap) should be pushed down into the juice each day, and the must be should also be stirred. A sheet of plastic or cloth should be placed over the fermenter to keep out fruit flies. Four to seven days after fermentation starts, press out the juice, and add the remainder of the dissolved sugar. Subsequent steps in winemaking can be done in the same manner as for grape wines.
If fruit wines are fermented to dryness, they are apt to be harsh, bitter, and/or lack desirable flavor. Sugar can make these wines very palatable. It can be added during fermentation, and some may remain as residual sugar that has not been converted to alcohol, or it can be added just before consumption of the wine. It is difficult to stop fermentation in a wine with some remaining sugar. One method is to use pasteurization to stop fermentation, but this technique is slow and tedious. The best technique is to ferment to a dry state and bottle when ready. When drinking, add an amount of sugar syrup (2 cups of sugar dissolved in 1 cup of hot water) that will raise the sweetness to the appropriate taste level. At this time the sugar will dissolved completely. Another method is to add sugar before bottling along with 200-250 ppm of potassium sorbate to inhibit fermentation (Eakin and Ace, 1975).
Unsulfured dried fruits such as raisins, figs, and dates produce wines resembling baked sherries. Coarsely grid the dried fruit and add 1 pt of water per pound (0.473 liters per 0.454 kg) of ground material (Amerine and Marsh, 1962). Bring to a simmering temperature and allow to cool. Strain and press out the juice through cheesecloth two or three times, and put the juices into a fermentation container. Adjust the juice to about 23° Brix by adding water or sugar, depending on the degree Brix.
Raisins contain almost sufficient acid to produce a good wine, but citric acid must be added to figs and dates before fermentation; about oz/gal (19.97 g/4 liters) is normally required. Add yeast and ferment under a fermentation trap. Siphon the new wine away from the sediment after fermentation is completed. Then follow the instruction given for making fruit wines.