2. About the Wine
• Wine is an alcoholic beverage made from
fermented grapes or other fruits.
• Different varieties of grapes and strains of yeasts
produce different styles of wine.
• Wine is usually made from one or more varieties
of the European species Vitis vinifera, such as
Pinot noir, Chardonnay, Cabernet Sauvignon,
Gamay and Merlot. When one of these varieties
is used as the predominant grape, the result is a
“varietal” as opposed to a “blended” wine.
3. Classification of Wine
Regulations govern the classification and sale of
wine in many regions of the world.
European wines tend to be classified by region
(e.g. Bordeaux, Rioja and Chianti.
The EU is a leading producer of wine. Producing
some 175m hl every year, it accounts for 45% of
wine-growing areas, 65% of production, 57% of
global consumption and 70% of exports in global
terms.
4. Non-European wines are most often classified by grape
(e.g. Pinot noir and Merlot). Market recognition of particular
regions has recently been leading to their increased
prominence on non-European wine labels.
Examples of recognized non-European locales include
Napa Valley, Santa Clara Valley and Sonoma Valley in
California; Willamette Valley in Oregon; Columbia Valley in
Washington; Barossa Valley in South Australia and Hunter
Valley in New South Wales; Luján de Cuyo in Argentina;
Central Valley in Chile; Vale dos Vinhedos in Brazil;
Hawke's Bay and Marlborough in New Zealand; and
Okanagan Valley and Niagara Peninsula in Canada.
Some blended wine names are marketing terms whose use
is governed by trademark law rather than by specific wine
laws. For example, Meritage (sounds like "heritage") is
generally a Bordeaux-style blend of Cabernet Sauvignon
and Merlot, but may also include Cabernet Franc, Petit
Verdot, and Malbec. Commercial use of the term Meritage is
allowed only via licensing agreements with the Meritage
Association.
5. Winemaking
Winemaking or vinification, is the production of wine,
starting with selection of the grapes or other produce and
ending with bottling the finished wine. Although most wine is
made from grapes, it may also be made from other fruits or
plants. Mead is a wine that is made with honey being the
primary ingredient after water.
In the context of wine production, terroir is a concept that
encompasses the varieties of grapes used,
elevation and shape of the vineyard
type and chemistry of soil
climate and seasonal conditions
the local yeast cultures.
6. Winemaking can be divided into 2 general
categories:
1. still wine production (without carbonation)
2. sparkling wine production (with carbonation —
natural or injected).
7. o Harvest
Harvest is the picking of the grapes and in many ways the first
step in wine production. Grapes are either harvested
mechanically or by hand.
8. Mechanical harvesters are large tractors that straddle
grapevine trellises and, using firm plastic or rubber
rods, strike the fruiting zone of the grapevine to
dislodge the grapes from the rachis.
Advantage :
Disadvantage :
able to cover a large area of vineyard land in a
relatively short period of time, and with a minimum
investment of manpower per harvested ton
the indiscriminate inclusion of foreign non-grape
material in the product, especially leaf stems and
leaves, but also, depending on the trellis system and
grapevine canopy management, may include moldy
grapes, canes, metal debris, rocks and even small
animals and bird nests.
9. Manual harvesting is the hand-picking of grape
clusters from the grapevines.
Advantage :
Harvest period:
Grapes are usually harvested from the vineyard from
early September until early November in the northern
hemisphere, and mid February until early March in the
southern hemisphere
Not only pick the ripe clusters but also to leave
behind the clusters that are not ripe or contain
bunch rot or other defects. This can be an
effective first line of defense to prevent inferior
quality fruit from contaminating a lot or tank of
wine.
10. The process of fermentation in
winemaking
After the harvest, the grapes are taken into a winery
and prepared for primary ferment. At this stage red
wine making diverges from white wine making.
• Red wine is made from the must (pulp) of red or
black grapes and fermentation occurs together
with the grape skins, which give the wine its
color.
• White wine is made by fermenting juice which is
made by pressing crushed grapes to extract a
juice; the skins are removed and play no further
role. Occasionally white wine is made from red
grapes; this is done by extracting their juice with
minimal contact with the grapes' skins.
• Rosé wines are either made from red grapes
where the juice is allowed to stay in contact with
the dark skins long enough to pick up a pinkish
color (maceration or saignée) or by blending red
wine with white wine. White and rosé wines
11. The process of fermentation in winemaking turns grape
juice into an alcoholic beverage. During fermentation,
yeasts transform sugars present in the juice
into ethanol and carbon dioxide (as a by-product).
In winemaking, the temperature and speed of
fermentation are important considerations as well as the
levels of oxygen present in the must at the start of the
fermentation. The risk of stuck fermentation and the
development of several wine faults can also occur
during this stage, which can last anywhere from 5 to 14
days for primary fermentation and potentially another 5
to 10 days for a secondary fermentation.
yeast + sugar alcohol + carbon dioxide
C6H12O6 2 C2H5OH + 2 CO2
Glucose/fructose ethanol carbon dioxide
12. --Primary fermentation--
Fermentation may be done in stainless steel tanks, which
is common with many white wines like Riesling, in an
open wooden vat, inside a wine barrel and inside the wine
bottle itself as in the production of many sparkling wines.
To start primary fermentation yeast may be added to the
must for red wine or may occur naturally as ambient yeast
on the grapes or in the air. Yeast may be added to the
juice for white wine. During this fermentation, which often
takes between 1 and 2 weeks, the yeast converts most of
the sugars in the grape juice into ethanol(alcohol) and
carbon dioxide. The carbon dioxide is lost to the
atmosphere.
13. During the primary fermentation the temperature is typically
For red wines; 22 - 25 °C,
For white wines; 15 - 18 °C.
For every gram of sugar that is converted, about 0.6 mL of
ethanol is produced, so to achieve a 12% alcohol
concentration (v/v), the must should contain about 20%
sugars (w/v).
14. Secondary or malolactic fermentation
During or after the alcoholic fermentation, a
secondary or malolactic fermentation can also take
place, during which specific strains of bacteria (lactic
acid bacteria) convert malic acid into the milder lactic
acid. This fermentation is often initiated by inoculation
with desired bacteria.
For example : it converts "crisp, green apple" malic acid
to "soft, creamy" lactic acid softening the taste of the
wine.
“Secondary" fermentation takes place inside the
bottle, dissolving trapped carbon dioxide in the wine
and creating the characteristic bubbles of sparkling
wines (champagne-like).
15. During the secondary fermentation and aging
process, which takes three to six months, the
fermentation continues very slowly. The wine is
kept under an airlock to protect the wine from
oxidation. Proteins from the grape are broken
down and the remaining yeast cells and other
fine particles from the grapes are allowed to
settle.
Potassium bitartrate will also precipitate, a
process which can be enhanced by cold
stabilization to prevent the appearance of
(harmless) tartrate crystals after bottling. The
result of these processes is that the originally
cloudy wine becomes clear. The wine can be
racked during this process to remove the lees.
16. Red grapes
After the primary fermentation of red grapes the free
run wine is pumped off into tanks and the skins are
pressed to extract the remaining juice and wine. The
press wine is blended with the free run wine at the
winemaker's discretion. The wine is kept warm and
the remaining sugars are converted into alcohol and
carbon dioxide.
Red wine is sometimes transferred to oak barrels to
mature for a period of weeks or months; this practice
imparts oak aromas and some tannin to the wine.
The wine must be settled or clarified and adjustments
made prior to bottling.
Sweet wines or off-dry wines
Are made by arresting fermentation before all sugar
has been converted into ethanol and allowing some
residual sugar to remain.
17. Grape
The quality of the grapes determines the quality
of the wine more than any other factor.
Grape quality is affected by variety as well as:
1. weather during the growing season,
2. soil minerals and acidity,
3. time of harvest,
4. pruning method.
18. Other types of
fermentations
Bottle fermentation
Bottle fermentation is a method of sparkling wine production,
originating in the Champagne region where after the cuvee has
gone through a primary yeast fermentation the wine is then
bottled and goes through a secondary fermentation where
sugar and additional yeast known as liqueur de tirage is added
to the wine. This secondary fermentation is what creates the
carbon dioxide bubbles that sparkling wine is known for.
Carbonic maceration
The process of carbonic maceration is also known as whole
grape fermentation where instead of yeast being added, the
grapes fermentation is encouraged to take place inside the
individual grape berries. This method is common in the creation
of Beaujolais wine and involves whole clusters of grapes being
stored in a closed container with the oxygen in the container
being replaced with carbon dioxide. Unlike normal fermentation
The resulting wines are typically soft and fruity.
20. The time from harvest to drinking can vary from a
few months for Beaujolais nouveau wines to over
twenty years for wine of good structure with high
levels of acid, tannin or sugar. However, only about
10% of all red and 5% of white wine will taste better
after five years than it will after just one year.
Depending on the quality of grape and the target
wine style, some of these steps may be combined or
omitted to achieve the particular goals of the
winemaker. Many wines of comparable quality are
produced using similar but distinctly different
approaches to their production; quality is dictated
both by the attributes of the starting material and the
steps taken during vinification.
Wine comes to our table