Chapter 2: What is Wine?

Chapter 2: What is Wine?

At its simplest level, wine is a beverage resulting from the fermentation of the juice from grapes. Fermentation is a very complex chemical reaction. The sugar content of the grapes' juices is transformed, by the action of the yeast, into approximately equal parts of carbon dioxide (CO2) and alcohol. Both sugar and yeast reside naturally with the grape. Sugar is in the inside and the yeast on the outside. Fermentation is impossible to begin without crushing the grape or at least squeezing it enough to put the yeast in contact with the sugar. Since most wines are fermented in open-top fermenters, the resultant carbon dioxide (CO2) gas escapes into the air.

The yeast multiplies and continues to work until all the sugar is converted to alcohol and carbon dioxide unless the winemaker takes steps to preserve some of the sugar in the wine. This procedure is discussed in a later chapter. The alcohol, along with many other special attributes brought about by fermentation, remain in the wine. The final product, though, is more than alcohol, since fermentation brings out many flavors and aromas inherent in the grapes. As many as 300 different constituents in wine have been identified to date.


For convenience in guiding the consumer, as well as assessing and collecting federal taxes, wines have been divided into three broad categories: table wines, sparkling wines and dessert (or aperitif) wines.

Table wines are defined as those with an alcohol level of between 7% and 14% by volume. They are typically on the dry side, ranging from under .1% residual sugar to 2.5%. Most experienced tasters cannot sense sugar at levels below .5% and cannot detect a change in the sugar level in increments of less than .5%. For example, you probably couldn't tell the difference in sugar levels between two wines if one were .7% residual sugar and the other 1%. But, you could probably tell which one was sweeter if one was .5% and the other 1%.

As the term implies, table wines are those that, over centuries, have been traditionally enjoyed with meals. On average, table wines contain 12% alcohol and are basically dry. Table wines can be grouped into three classifications: varietal, generic and proprietary names.

Varietal wines are made predominantly from a single-grape varietal, such as Cabernet Sauvignon or Chardonnay. By law (presently), a wine must contain at least 75% of wine from the grape varietal stated on the label. In practice, the content usually is on the order of 90% and often 100%.

Non-varietal wines are created by blending wines from several grape varietals into a harmonious whole. Wines labeled "Chablis," "Burgundy" and "Rosé" are generic wines. Fortunately these terms, which refer to actual geographic locations such as Chablis (in France's Burgundy region), are being phased out and replaced with "White Table Wine" or "Red Table Wine."  Using the names of French wine-growing areas for domestic wines has the same effect on the French as it would on the Americans if the French labeled a wine "Napa Valley Red."
Proprietary wines are usually a blend of different grapes to attain a specific goal that could not be reached by using just one grape. The term "Meritage" was conceived for those wineries wishing to make wines from the "classic Bordeaux" varietals, namely Cabernet Sauvignon, Merlot, Cabernet Franc and occasionally Petite Verdot and Malbec for red and Sauvignon Blanc and Semillon for white.

sparkling wines are made by allowing a still wine to go through a second fermentation in a closed container. The container, whether a tank or a bottle, holds the carbon dioxide generated by the second fermentation in suspension, as opposed to letting it escape into the air, and that accounts for the bubbles.

"Champagne" is a sparkling wine made in the French region of Champagne using the French method of production referred to as "Methode Champenoise."  "Spumante" is the Italian equivalent of Champagne, and in German "Sekt" means the same. Producers in the United States, South America and Australia often label their sparkling wines "Champagne," but European producers outside of the French Champagne region are not allowed to use the term by The European Economic Community (EEC) law.

The three methods used in the creation of sparkling wines are: the charmat, or bulk process; the transfer process; and Methode Champenoise.

Methode Champenoise is considered the only true way to create sparkling wine. It is the only technique used to produce Champagne in France. However, other areas in France outside of Champagne make sparkling wine, and they do not need to use the Champagne method. The finest Sparkling Wines produced in California and elsewhere are all created by this Champagne method. It is the most expensive of the three since it involves more labor. Each bottle may be handled 100 times or more.

To the surprise of many, Champagne is made primarily from red grapes. Champagne is normally pale white in color because the juice of the red grape is white. A red wine can only be made if the juice is allowed to come into contact with the skins during and after fermentation. Red wines are made by allowing the white juice of the grape to come in contact with the red pigments in the skins for an extended period of time (7-14 days). If the grape is crushed quickly, only coming in contact with the skin for a few minutes, it will retain its white color.

As with any sparkling wine, the Champagne method starts with a still wine. The base wine, called the "cuvee," is usually a blend of several different vintages. This is done so that the winemaker can blend several different lots to make a cuvee that is consistent from one year to the next. This is more important in the Champagne region of France where the climate conditions are very unpredictable and only 3 or 4 years in 10 produce the finest vintage Champagnes.

The grapes for Champagne are picked much earlier than grapes for table wine. At this stage in their development, there is very high acid, 1-1.5%, and very low sugar, 15-18%. These figures could not make a very good table wine as it would be too tart and acidic. The grapes are crushed until they are totally dry, leaving a wine that is tart, crisp and about 9-10% alcohol.

One of the most difficult jobs in winemaking is the blending of a Champagne cuvee. The master blender must take different lots of these very high acid, tart wines and imagine what they would taste like if they had bubbles. In some cases a blender could work with 100 different lots creating a cuvee using as little as 1% from a single lot.

Once the cuvee is decided upon, it is bottled in the traditional sparkling wine bottle to which a tiny amount of sugar solution and yeast is added, and the bottle is sealed with a crown cap. Fermentation takes place all over again (referred to as the second fermentation), and the sparkling wine is born.

As the yeast converts the sugar to alcohol (this raises the total alcohol level to the desired 12% level), the other byproduct, carbon dioxide, has no place to go but back into the wine, thus making those wonderful little bubbles that separate Champagne from all other wines. The yeast cells die off and fall to the bottom.

The difference between the three methods lies in the aging and clarification technique since, with the Methode Champenoise, the sparkling wine never leaves the bottle it was created in. Once each day, the cellarman gives each bottle a slight shake and quarter turn. This is called riddling and the rack it is done on is called a riddling rack. With each turn the bottle is reinserted at a new, more upright angle until it is perfectly vertical, cork side down.

After about 2 to 6 months of this treatment, all of the sediment (expired yeast cells) is collected at the neck of the bottle and the yeast, having done their best, have retired to yeast heaven. The bottles are placed in special racks for aging on the expired yeast cells for as many as 1 to 5 years. The longer they rest on the yeast, the more complex the flavors become. The wine can actually pick up a "yeasty" component reminiscent of fresh baked bread.

While the sparkling wine is now basically complete one problem remains. The expired yeast cells would form an unsightly, cloudy haze if the bottle were turned upright. They must be removed without disturbing the delicate sparkling wine, which they helped create. To accomplish this task, the bottles are carefully removed from the racks and placed neck down in a solution, usually liquid nitrogen. The bottleneck and approximately the first 2 inches of wine are frozen. The crown cap is removed and the CO2 pressure within the bottle (approximately 70 lbs. per sq. in.) forces out the 2-inch ice "plug" containing the sediment. This is how the wine is clarified of the sediment (expired yeast cells). The bottle is then filled with either the same sparkling wine for a Natural (very dry) wine or it is topped off with a touch of sugar and wine for Brut (dry) or Extra Dry (slightly less dry) versions. It then receives its traditional cork, wire hood and foil, and may be sold or held for additional aging. Sparkling wine made by the Methode Champenoise technique can be identified by the legend "Made in THIS bottle."

The terms Natural, Brut and Extra Dry carry no legal definition. For instance, it is generally accepted that a Brut has between .75% and 1.5% residual sugar and an Extra Dry between 1.2% and 2%. That would mean that one producer's Extra Dry could technically be drier than another's Brut. This much sugar in a table wine would taste sweet to most people. However, because the grapes used for sparkling wine are picked at lower sugar and much higher acid (and the bubbles actually hide some of the sweet taste because not all of the liquid is attacking your taste buds at the same time), the perception of sweetness is not as apparent. While many sparkling wine drinkers prefer dry wines, most would find a Natural "too dry" as the acid is fairly penetrating.

With the transfer process the cuvee, together with a tiny amount of the sugar and yeast solution, is stored in a large container, usually glass, so it can be said to be made in the bottle. The secondary fermentation takes place within this large bottle, which is usually much larger than the one in which it will be sold, sometimes 10-20 times larger.  The resulting sparkling wine is then aged in the bottle for a period of 6 months to a year. Since the secondary fermentation produces "sediment," mainly spent yeast cells, the sediment must be removed. The cap is removed and the bottle contents poured into a vat. This must be done in a pressure-controlled environment or the bubbles will dissipate faster than you can say "pop."

The sparkling wine is then filtered and rebottled in a new bottle under high-pressure conditions to insure minimum loss of CO2. The transfer process is more expensive than charmat because of its longer aging time "on the yeast", and the handwork involved. It is less expensive than Methode Champenoise because of the method used to filter the yeast cells. Modern methods for Methode Champenoise production, which include the gyroplate for riddling an entire pallet (48 cases) at a time, makes the transfer method almost all but obsolete. Transfer process sparkling wine is identified by the term "Made in The Bottle."  Ideally it was the gap between the expensive, but tasty, Methode Champenoise and the inexpensive, but bland, charmat.

With the charmat process, the base wine, or cuvee, is placed in a sealed, pressure-resistant tank and injected with a small amount of sugar solution and yeast. The yeast attacks the sugar causing a second fermentation, which generates CO2 gas.  Since the CO2 gas cannot escape the tank, it is absorbed by the wine and forms bubbles. The finished sparkling wine is then filtered for clarity and bottled. Sparkling wine produced by this process is the least expensive because it requires no handwork, can be produced rapidly, and spends very little time in contact with the yeast. This is an important point because the wine's extended contact with the spent yeast cells is what gives sparkling wine its unique flavor.

Besides the method of production, the grapes, or cuvee, are also very important. The best grapes for making Champagne and sparkling wine are Pinot Noir, Pinot Munier (mostly used in France) and Chardonnay. Most producers will not go through the trouble and expense of making wine in the traditional Methode Champenoise way and use inexpensive grapes. Conversely, charmat producers don't need expensive Chardonnay and Pinot Noir grapes for what will eventually be a very inexpensive wine. The government makes no distinction, however, imposing the stiffest tax on sparkling wine over any other type; almost $1.00 per bottle regardless of whether it is the finest vintage Champagne, or the lowest charmat bulk product.

Aperitif and dessert wines, although enjoyed on different occasions, are two groups usually lumped together because of their legal definitions based on alcohol content. In the making of what we call fortified wines such as Port, the fermentation process is arrested before completion with the addition of a neutral spirit such as grape alcohol. As the yeast is converting the sugar to alcohol, the addition of spirits raises the alcohol level to 20%. Since yeast cannot live in an alcohol environment of more than 17%, this procedure will effectively kill off all the yeast cells. Because they have not finished converting all the sugar to alcohol and CO2, whatever residual sugar is left before the addition of the spirits will now be in the finished wine. In the case of Port the residual sugar could be as low as 8% or as high as 12% depending on the desire of the winemaker.

The Federal Government defines any wine that has been fortified with alcohol by the addition of brandy or neutral spirits as a liqueur. The taxes paid on these products are almost 3 times that of table wines. Their alcohol level ranges from 14% to 21%. It is possible (indeed, it is done often) for a table wine to reach a natural alcohol level of as much as 17%. Once the wine crosses the 14% border it must pay the extra tax regardless of whether it reached that level naturally or not. This tax accounts for the large number of table wines labeled 13.9% alcohol.

The most popular wines in the aperitif and dessert category are Sherry and Port. Port, a red wine quite sweet to the taste, takes its name from Portugal where it first was created. Port-styled wine is made by many countries including South Africa, Australia and California. Port nearly always is a blend of several grape varietals. Its high level of sweetness makes it ideal with desserts, or as a nightcap.

Sherry is an amber-colored wine, which originated in the Spanish town of Jerez. The English, the biggest importers of Sherry in the world, couldn't pronounce Jerez (Hare-eth) so they called it "Jare-ezz" and finally Sherry. It ranges from very dry to very sweet. The driest and lightest colored Sherry is called "Fino."  Amontillado is a Sherry of medium amber hue, and usually somewhat sweeter than Fino. California Sherries labeled simply "Sherry" fall somewhat into this category but do not compare directly with the Spanish version. The heaviest and most full-bodied Sherry produced in Spain is "oloroso." It is usually rather dark in color and can be either dry or sweet. The Fino and Amontillado types are aperitif wines, while the oloroso is either a food or dessert wine.


The large and luscious late harvest wines are produced from grapes, which have been left on the vine longer than those destined to become table wines. They develop a naturally higher than normal sugar level, thus the resulting wine may be higher in alcohol, often over 14%. More often, however, they are higher in sugar since the fermentation process is arrested before all the sugar is converted. This is done by either putting the wine through a filter fine enough to remove the yeast or lowering the temperature of the wine to almost freezing (34˚F). This causes the yeast to stop working and fall to the bottom of the tank where it can be removed easily.

Late harvest Zinfandels were popular in the late '60s and early '70s, but have almost disappeared due to lack of consumer interest and competition from Port.

White wines in the late harvest style are generally made from the Riesling grape, as is traditional in Germany where they first evolved. In France, a similar style of wine is called "Sauternes."  This wine is made from a blend of Sauvignon Blanc and Semillon.

Late harvest Rieslings are made in several different sweetness levels similar in style to those found in Germany where they are labeled as Spätlese (late picked), Auslese (very late picked), Beerenauslese (individually picked ripe clusters) and Trockenbeerenauslese (individually picked ripe grapes). In California, these terms are illegal to use; therefore, Late Harvest is generally the only term applied to the wines in this style.

One of the key terms in late harvest wines is "Botrytis". It refers to a special, beneficial mold called Botrytis cinerea. This mold causes the grapes to shrivel and dehydrate, while at the same time concentrating their natural flavors and sugars. The result is a rather rare wine, very sweet, with the flavor of honey and apricots. They are very difficult and very costly to produce and, as a result, very expensive. For example an acre vineyard planted with Chardonnay would yield about 200 to 250 cases of fine table wine. That same vineyard may only yield 50 cases of a late harvest wine.