wine production
Winemaking or vinification is the production of wine, starting with the selection of the fruit, its fermentation into alcohol, and the bottling of the finished liquid. The history of wine-making stretches over millennia. The science of wine and winemaking is known as oenology. A winemaker may also be called a vintner. The growing of grapes is viticulture and there are many varieties of grapes.
Winemaking can be divided into two general categories: still wine production (without carbonation) and sparkling wine production (with carbonation – natural or injected). Red wine, white wine, and rosé are the other main categories. Although most wine is made from grapes, it may also be made from other plants. (See fruit wine.) Other similar light alcoholic drinks (as opposed to beer or spirits) include mead, made by fermenting honey and water, and kumis, made of fermented mare's milk.
8. Yeasts involve in fermentation should
possess:
•Rapid and relevant carbohydrate
fermentation ability;
•Appropriate flocculation and
sedimentation characteristics;
•Genetic stability;
•Osmotolerance
9. Yeasts involve in fermentation should
possess:
•Ability to produce elevated
concentration of ethanol;
•High cell viability for recycling
•Temperature & Ethanol tolerance
12. Products obtained by alcoholic
fermentation of grapes, grape juices,
fruit juices, berries, rhubarb, honey
etc by yeasts.
Wines
13. Kinds of wines
• still wines
• sparkling wines
•artificially carbonated wines
14.
15. Grape used for production of wine
• Varies in grape species and cultivars
– Vitis vinifera, V. labrusca
– Cabernet Sauvignon, Chardonnay, Gamay, Mission, etc. refer to
different varieties or cultivars of the Vitis vinifera
Cabernet Sauvignon Chardonnay Gamay Mission
– Different in compositions (sugar contents, pigmentation, etc.)
– Different climates and soil preference
– Wine quality varies greatly
• Climate factors have important effect on grape quality and maturity
16.
17. Grape Composition
• Water 70-85% of the juice volume
• About 20% sugar
– Simple sugars largest constituent of grapes or must
– Important for S. cerevisiae to produce ethanol
– Glucose (~50%), Fructose (~50%, increase in over-ripened grapes), sucrose
(<1%, in V. labrusca up to 10%)
– Other sugars very low conc.
• Sugar content in final product
– “dry”: 0.1%-0.2%
– “sweet” >10g/L
– “very sweet” as much as 100g/L-200g/L
18.
19. Organic Acids
– Second in content constituent in must
– Very important in wine quality
• Provide low and well buffered pH (3.0-3.5)
• Antimicrobial activities
• Stabilizes anthocyanins (color, antioxidant, desirable
flavor)
• Volatile acids (acetic acid and others) very low
• Fixed acids (malic acid and tartaric acid ~5:1) important
to maintain the right acidity of wine and anti-spoilage,
affected by environmental factors
21. Steps involve in fermentation of
wine:
• Preparation of must (grape juice, crushed
grapes, fruit juice].
• inoculation of must with wine yeasts (2-
5% ].
• aeration of must to encourage the growth of
yeasts and to facilitate the extraction of
pigments from a skin (mixing must twice a
day ].
22. Steps involve in fermentation of
wine:
• Active fermentation:
- red wines 24 -27 0C; 3-5 days;
- white wines 10-21 0C; 7-14 days;
• separation of fermented juice from residue
(pomace);
• placing fermented juice under light CO2 pressure
• secondary fermentation: 21-29 0C, 7-11 days.
• aging of wines.
24. Wine Production
1. Viticulture
Factors which inflence grape’s flavor:
•climate of the vineyard’s region
•drainage around the vines
•humidity of the region
•sun exposure.
•soil quality
25. Wine Production
2. Harvesting
•Grappes are picked up by hand or
mechanically
•Descision of harvest informed by level of
sugar and acid
•weather forecasts
26. Wine Production
3. Stemming/Crushing
Stemming is the separation of the stems and
grapes (which are sends to the press)
Crushing: A horizontal press squeezes
the broken grapes, separating the
fresh juice (must) from the skins
(marc)
After crushing starts the fermentation
process.
27. Wine Production
4. Fermentation
•sugar and acids that naturally react
with wild yeasts
•Vineyard adding their own yeasts
•fermentation can take from 10 to
30 days to convert natural sugar to
alcohol.
5. Draining
Liquid wine is drained from the vat without being pressed and go into
barrels (free-run wine). The remaining pulp retains about 20% of the
wine.
28. Wine Production
6. Pressing
The remaing pulp, after draining, is pressed to
squeeze out the press wine. The press wine tends
to be dark, harsh and unpalatable, and is mixed
with free-run wine to produce something decent.
7. Mixing
The free-run wine and press wine, always from the same source, are mixed
together in appropriate ratios to obtain the desired balance.
29. Wine Production
8. Clarification
Clarification is the step of stabilisation of fermentation.
During clarification all remaining solids are removed from the fermented
liquid.
Clarification done in numerous ways:
•fining, a process that calls for the addition of substances that cause the
solids in the liquid to adhere to one another and sink to the bottom of
the vat
•running the liquid through coarse and fine filters
•siphoning the liquid off the top of the fermenting vats after the solids
have settled to the bottom
30. Aging of wine
Once fermentation is complete, the wine
can be transferred to oak barrels for aging
for 6 to 24 months. But, not all wine is oak
aged.
The barrels are usually made from either
French or American Oak, which give
differing qualities to the wine.
Some wine is aged in old barrels and some
in new to produce different characteristics,
as well.
The wine maker will then blend the various
lots of wine to produce a finished wine
ready for bottling.
Fermentation Tanks
Barrel filling
Barrel aging
Active Yeast Cells
31. Bottling and storage of wine
After the aging of wine is
complete it is transferred to
bottles.
Most wine is consumed within
three years of bottling.
But some fine wines gain
added flavor and bouquet with
time in the bottle if it is stored
at 50 to 60 F. But, humidity is
also important so that the
corks do not dry out, which
spoils the wine.
The wines commonly aged in
the bottle are:
– Cabernet Sauvignon (Red)
– Pinot Noir (Red)
– Chardonnay (White)
– Champagne (White Sparkling)
– Port
– Sherry
Bottling line
Bottles being filled
Large Commercial Cellar
Small in-home cellar
32. Differences in making red and white wine
White Wine:
Grapes for white wine are
harvested and pressed.
The must is fermented in
stainless steel tanks.
Some white wines, such as
Chardonnay, is aged in oak
barrels.
The wine is bottled
Most white wines are not
bottle aged but consumed
with in 3 years of bottling.
However, an exception is
particularly fine wines made
from Chardonnay and
Champagne.
Red Wine:
Grapes for red wine are
harvested, crushed.
The must is left with the
skins during fermentation to
produce the red color.
Red wine is commonly aged
in oak barrels for 6 to 24
months.
The wine is bottled.
Many red wines are ready to
drink after bottling.
However, some red wines,
such as Cabernet
Sauvignon, will benefit with
some bottle age.
33. Production of fortified wine
Grapes for fortified wines are
harvested like for other wines.
Depending on the type of wine,
the must may be handled in
different ways to intensify the
flavor before and during
fermentation.
Most fortified wines have an
addition of alcohol (brandy) to
stop fermentation and increase
the alcohol content.
Fortified wine maybe aged in
oak barrels before bottling.
Many fortified wines will benefit
with bottle age.
34. Production of Blush & Sparkling Wines
Blush Wine:
Red grapes are harvested
for Rose or Blush wine.
Before fermentation the
must is left with the skin for
a short time.
The must is fermented in
stainless steel tanks.
If a sweet wine is desired
then the fermentation is
stopped before all of the
sugar is consumed.
The wine is bottled
Blush wines are not
commonly bottle
aged but consumed
within 3 years of
bottling.
Champagne (Sparking) Wine:
Grapes for sparking wine are
harvested and pressed.
It is fermented like a white wine.
More sugar and yeast is added to
the wine.
The wine is bottled.
The additional sugar and yeast
produce carbon dioxide, which
carbonates the wine.
The second fermentation is
stopped.
Most sparkling wines are made to
drink young. But, fine Champagne
will benefit with additional bottle
age.
36. Sparkling Wines
Champagne is carbonated wine that is made in the
Champagne district of France. Other sparkling wines
are made by the same process, but aren’t technically
called champagne.
The carbonation comes from adding some sugar and
fresh yeast to bottled wine. The yeast ferments this
extract sugar, and the carbon dioxide gas is trapped in
the bottle.
It is necessary to remove the dead yeast after the
fermentation is complete. This is tricky: you can also
lose all of the carbon dioxide.
During this fermentation, the bottle are stored upside
down, so the yeast accumulates in the neck. After
fermentation is complete, the necks are frozen . The
bottle are opened and an icy plug of yeast and wine
comes out. A little replacement wine is added, and
the bottles are quickly re-sealed.
37. Distilled Spirits
• To produce stronger alcohol, distillation is
needed. The principle is that ethanol boils at a
temperature lower than water. So, the alcohol
boils off, leaving the water behind. You just
need to capture the alcohol vapor and
condense it.
– The first 1% or so of what distills off
has headache-inducing compounds
in it, and it is generally discarded.
38. Distillation was invented by the Arabs around 700 AD.
The word “alcohol” comes from Arabic: al’kuhul, which refers to
kohl, a preparation used to darken the eyes. Alternatively, al’ghoul,
which means monster or spirit. This word origin is somewhat
debatable.
Alcohol concentration is measured in proof, where each proof is 1/2 %.
So, 80 proof means 40% alcohol. Most distilled spirits are 80-100
proof.
Alcohol can only be distilled to 95%. It is colorless and tasteless. The
color and taste of distilled spirits come from other byproducts of
fermentation and aging that remain after distillation.
39. Brandy
• Brandy is distilled grape wine that has been aged in oak
barrels for up to 50 years.
– Cognac is brandy produced in the Cognac district of France.
• .
• Other fermented fruits can be distilled to produce fruit
brandies of various kinds: peach, apricot, plum, cherry,
blackberry, etc.
•
• The gunpowder test: if brandy had been distilled to a high
enough alcohol concentration, a pinch of gunpowder put
in the brandy would ignite when the brandy was set afire.
40. Rum
• The starting material for rum is molasses, the main
byproduct in sugar manufacture.
• It is first fermented (by adding yeast) to generate
alcohol, and then distilled. Aging it in wooden barrels
gives it color and flavor.
• Light rum
• Golden rum
• Dark rum
41. Whiskey
• Whiskey is a distilled spirit made from fermented grain.
• aged in wooden barrels, usually made from white oak charred. Some
whiskies are distilled several times.
• . Malt whiskey is made using only malted barley, without other grains.
• , grain whiskey is made by mixing malted barley with other grains.
• Different forms of whiskey use different grains. The legal systems of various
countries define the types.
– Bourbon whiskey is made from corn. It was invented in Bourbon County,
Kentucky and is a distinctly American product.
– Scotch whiskey is made in Scotland from malted barley plus other grains. The
smoky flavor comes from drying the malted barley over a peat fire.
– Rye, wheat, and corn whiskies are made from the respective grain.
43. Gin
• Gin is a distilled spirit flavored with juniper berries
• Gin is made by fermenting wheat, corn, and rye with malted
barley, and then distilling it with juniper berries and other
spices mixed in. It does not need to be aged,
• Gin was invented in Holland,
• Gin became very popular among working class people in
England, because it could be brewed from grain unfit for
making bread or beer,
Gin Lane, London, 1751
45. Vodka
• Vodka is the traditional distilled spirit of Russia,
Poland, Finland, and other Eastern European
countries.
• Vodka is made from fermented grains (mostly wheat
and rye), or from potatoes. It is distilled repeatedly
until it is almost pure alcohol (95% = 190 proof).
Then, it is diluted to a drinkable concentration,
around 40% alcohol.
• Flavoring is sometimes added at this point, but
pure vodka is unflavored.
• Vodka is not aged.