Topic 12: Wine: It was a very good year
What is
wine?--Wine is made by fermenting
fruit juice with wine yeast, which energetically try to convert the high
concentrations of fructose and glucose entirely into ethanol, which then kills
them. Wine yeast can be said to be
sugarholics who meet the fate of some alcoholics.
We are talking about wine made from the fruit of the grape vine here.
Wine has more alcohol than beer, but less than distilled drinks.
What
is the big deal with aging of wine?--Wine
does not smell like grape juice with ethanol in it.
Why? Aging.
In the process of fermentation and aging the "chemistry"
gradually becomes more complex as compounds
react with each other, and together they form an entirely new mix with a
new aroma, that of wine. It
has been correctly stated the drinking wine is in fact drinking dead yeast
killed by their excrement, which is the ethanol of course.
Alcohol is a poison, but it also seems to lower the risk of heart attacks
when drunk in moderation. Wine
enjoys a reputation as diverse as any food.
Some people love it and others hate it.
Americans generally do not go for wine like the Europeans. Good wines are
usually incredibly expensive and wine gives
some people severe headaches. It is
touted as a sign of a relaxed, cultured lifestyle, and lowers the risk of heart
attacks. While many fruits are made
into wine it usually means the fruit of
the grape. Mead is fermented
honey and water.
Wine
is made from the fruit of Vitis species and dates from the dawn of civilization---Wine
is made from several species of the woody perennial vine
Vitis, which occurs in both the old and
New World
and has about 50 species.
There is no evidence wine was ever made in the
New World
before the wine-loving Europeans arrived.
The best wine comes from Vitis vinifera, which is native to the
Old World
, specifically the Caucasus of Central Europe,
and was domesticated before recorded history. Wine-making is one of the oldest
cultural inventions of western civilization.
By the time of Tutankhamen (1352
BC) wine jars were being labeled with the year of the vintage, the name of the
vineyard, the name of the wine maker, and the region of production.
Domestication
of the grape involved selecting for a monoecious
cultivar instead of the native dioecious species.
All western civilizations
describe wine, including Greek, Roman,
Hebrew as far back as their written records go. The Greeks stored wine in
vessels smeared with pine pitch, to prevent leakage, which gave the wine a
resinous flavor. Now this flavor is
added to make retsina wines.
The oldest evidence of wine making comes from
Iran
about 5500 years ago, but it was certainly going
on before that.
Romans,
wine and Bacchus.
Eat, drink, and generate taxes Romans were urged on by Corporate Rome.
The Roman empire managed itself like Rutgers Incorporated, but instead of
selling off soft drink concessions to the highest bidder and ripping off
students and parents at football games, they ran a worldwide trade in wines in
most of the regions still renown for wine making, including
Gaul (France), where they planted the vineyards which gave rise to the
great French wine industry. Roman
vintages were discussed in literature and records abound.
And unlike
Rutgers
, they had a winning team for a long time.
Maybe things will be different this Fall.
But is it really that important? The first historically great Roman wine
was called Opimian (produced about 121 BC).
Wine,
lead poisoning and the fall of the
Roman
Empire
.
You thought
Rome
fell because of lead
plumbing, right? Wrong.
It was the lead in wine flasks. The
Roman aristocracy drank wines imported from
Egypt
and
Phoenicia
in large clay flasks called amphorae, which were sealed
with a ceramic glaze that contained high quantities of lead.
The acids in the wine dissolved some of the lead that then ended up in
the stomach of the drinker. The
remains of the ruling classes have a lead content in their bones
high enough to have been lethal. The
peasant bodies did not have the high lead
content, and they drank from wine not stored in amphorae.
Everyone drank from the same lead-lined Roman aqueducts that provided
water to the cities. But cold water
does not dissolve lead appreciably and goatskins do not contain lead.
After
the
Roman Empire
fell
the art of wine making was nearly lost. The art of wine making was guarded by
monks as part of ritual, and one of the good things in life. Monks planted
vineyards and refined
wine making with new techniques still in use today.
Chancre portrayed monks as hard drinkers who loved a good time.
Wine is saved again--With Prohibition wine was banned in the
US
, and most wineries were forced to shut down,
just like most breweries were closed. A
great loss of diversity ensued that has taken years to restore.
Only a few wineries were allowed to operate and were allowed to sell wine
only to the church for religious purposes. Nevertheless
the skills were preserved which set the foundation for the later explosion of
the
California
wine industry.
Welch’s grape juice--The process of pasteurization, which is heating wine or milk to kill
microorganisms, was not used on
grape juice in this country until Prohibition.
The process was put on the market by the Welch Company.
Up until that time all Methodist churches celebrated the Lord's Supper
with wine. This was replaced by
grape juice shortly after the marketing of the Welch product.
Oddly enough, one of the major bishops at the time was Bishop Welch.
Vitis labrusca is the fox grape,
and makes foxy wine--The
only significant N. American Vitis species is V. labrusca, which grows in
Eastern N.A., and has been selected to form
Concord
, the most famous, but not the best
cultivar of the labrusca type. Its
skin has a mucilaginous inner layer, so it squirts out the contents when the
grape is squeezed. The labrusca
grapes are more cold tolerant than the viniferas, but are not as sweet.
They are also more disease resistant.
Climate
and soil are important to wine--That
is a major understatement,. One of
the economic bases of the wine
industry is the limited number of places that can grow good grapes for wine.
It takes just the right soil, often a rather poor soil, and just the
right climate, and the best weather conditions, to make the best grape.
The sugar, acid and pigmentation of the grape are all strongly affected
by the temperature, and amount of sunlight in the growing season.
If the soil is too good the grape leaves and shoots grow too much and do
not put enough energy into the grapes themselves.
Fertilization is kept to a minimum. It
must be well-drained, and not very high in organic matter or in minerals.
At first this seems intuitively contradictory to what one would expect.
Unlike the tea grower, the goal of the vintner is not to produce leaves,
but berries. Cloudy summers are death to good wine, and rain late in the season
is terrible. Most of the time in
France
something bad happens to prevent a great
vintage.
Phylloxera
was a bad bug--Once upon a time there
was a root parasite of the North American
labrusca grape, which did not harm it very much.
Some Europeans (1855-60) took
rooted cuttings of this plant to
Europe
to breed a better grape, and
introduced phylloxera to V. vinifera orchards.
The phylloxera liked vinifera very much, and did a lot of damage,
practically knocking out the Euro-vineyards. Then someone got the bright idea
of replacing the vinifera rootstocks with labrusca
by grafting, which was done with great success.
It saved the day.
Divide the % sugar in grape juice
by 2 to get alcohol %--To
make wine, the grapes have to have a high % sugar, which is fermented by
yeast into alcohol. The more
sugar the more alcohol, to a point. Grapes
typically accumulate about 20-24% sugar by the time they are ripe, which means
they make wine with about 10-12% alcohol.
Fermentation and aging--Besides
converting the sugar to alcohol, many other chemical changes take place in
fermentation and aging that creates the highly complex aroma of wine.
The acidity of the grape will have a big effect on the final wine, as
will the presence of a vast array of other compounds.
Sauterne
wine is made from grapes purposely
infected with a mold called Botrytis cinera that removes much
of the water from the grapes, generating near raisins on the vines. At the same
time, sugars are concentrated in the grapes giving the wine a greater sweetness
and a higher alcohol content than other wines without the fungus.
Botrytis
cinera infects Rhine grapes also, which are allowed to overripen,
even rot, or dry out and form raisins on the vine before they are picked, producing
different flavors, depending on when
they are picked, as follows: spatlese
(late gathered) is from late picked grapes that are not overmature yet; auslese
(picked out, selected) from overmature bundles of grapes picked individually; beerenauslese,
(selected berries) is from grapes showing rotting and drying; trockenberenauslese
(dried, selected berries), is from rotted grapes that have dried almost into
raisins. The same mold is responsible for rotting here as in the sauvignon
grapes.
Picking
is followed by pressing--Pressing
used to be done with the feet, now done with a press. Not too hard to break
seeds, which are bitter and could add a bad flavor.
White wine is made by removing the skins immediately, rose wine has skins
left during first part of fermentation, and red wine has skins left during all
of fermentation.
Fermentation
of the juice (must) is next--Fermentation
happens naturally in grapes.
Yeasts will grow naturally on the grapes and during pressing will
mix with the grape juice and begin to ferment it.
Prior to this century, there was no such thing as "grape
juice". Until a pasteurization
process was developed, all grapes began to ferment into wine as soon as they
were crushed and the natural yeasts exposed to the sugars in the juice.
How
to ferment--Take the expressed grape
juice, now called must or new wine,
plus the pomace, which is all the skins,
seeds, and whatever else is in there, and dump it into a fermentation vat;
make sure there are no leaks. Temperature
matters a lot, and is different for white
or red wine. Kill all the
microorganisms with pasteurization or
sulfur dioxide in the must in the vat and then add new wine yeast,
Saccharomyces ellipsoides. Sulfur
dioxide removes oxygen and kills molds, yeasts and aerobic bacteria, but can
cause headaches and increased acidity of gastric juices.
Fermentation means that the sugar is converted to alcohol by the yeast.
Fermentation goes rapidly for a couple days
Pomace floats--The
pomace floats up to the top after a while, and shuts off the oxygen to the must
below, keeping bacteria away, which might turn the alcohol to vinegar.
Alcohol
levels rise to about 15-18% over the course of several weeks,
which stops the activity of the yeast.
Fermentation slows when the sugar concentration in the must drops below
0.1%. Most of the sugar is gone now.
To make a sweet wine, you stop the fermentation earlier, when there is
still sugar around. How to stop
fermentation: add alcohol, sulfur dioxide, or pasteurize.
The wine smells like grapes now, with alcohol, nothing special.
Racking--This
means putting into clean barrels, which is done in the fall, then again in the
spring, and again in the following fall for red wines.
What is the point of racking? To
get rid of the precipitated dead yeast cells, precipitated tannins and other
junk that floats down to the bottom of the barrel. The wine is left in the
barrel, the final racking, for 1-3 years, during which the flavors begin to
combine, to marry. In chemical terms
the acids and alcohols chemically combine to form a new fragrant compound called
an ester, which evaporates and makes the wine flavor, called the bouquet.
When to stop the racking? It
takes experience, and has a big effect on the quality of the wine.
Fining--This
is a way to clarify the wine which is done over a two or three month period
inside the barrels, the function is to remove junk particles in suspension,
which would make the wine cloudy, by
adding things like clay, gelatin or egg whites, which combine with the
impurities and then precipitate. Wine
is also chilled to remove tannins, which taste bitter, and then filtered one
last time before the next step.
Bottling
and aging--Wine
is put into bottles, labeled and stored on the side to keep the cork wet.
The label is a big deal in wine. It
indicates where the wine was made, if it was made by blending several varieties,
and the year it was made, which makes a big difference in quality.
Wines continue to age in the bottle, which means chemical reactions
proceed slowly, with white wines aging much more rapidly and being through in
2-4 years, while reds can age for 30 years or more.
The cork was invented by a priest
named Dom Perignon but he is much better known for another contribution,
champagne.
Champagne
--It is a
carbonated wine, supposedly invented one night by Dom Perignon, a
Benedictine monk in a monastery who worked in the wine cellars.
As you will see champagne can not be invented over night, as in the song.
Dom knew that wine continued to age in a corked bottle. For what ever
reason one day he removed the cork from a
few bottles and added a little more sugar and yeast. He then replaced the
cork and waited. Tradition has it
that the day he opened his new creation the Brothers were above him in the
chapel singing hymns. When he tasted
the now carbonated wine he ran up into the chapel and declared "Brothers,
come quickly...I am drinking stars". He
had invented champagne.
How to make champagne the
old-fashioned way: Make some wine and
rack it over the winter, mix some varieties together and let it ferment in the
summer in bottles, the second fermentation; let it rest a couple years in each
bottle. The bottle is turned on end
and the sediment settles out in the neck; the neck is frozen, the cork removed
and the sediment comes out; some sugar is
added back to the wine, which still has yeast, and
the cork is wired on, since pressure will develop; carbon dioxide is released in
the third fermentation, which goes into solution under pressure.
Fermentation stops and some sugar is left, depending on how much was
added. The final dryness of the
drink is classified: brut has less than 0.2% sugar, extra dry has less than 0.5%
sugar, sec has up to 2%, and doux is 3-4 % sugar.
Aperitif
and dessert wines--These have alcohol
added to the wine, and other things are done to them to alter the color and
flavor from a table wine.
Sherries--These
come from Spain, have a long fermentation
of 3 months, with a film of yeast developing on top at the end, giving it an
unusual flavor; grape brandy, which
is a distilled product made from wine, may be added before the fermentation is
ended, making a sweet
sherry
used as a dessert wine, called the
oloroso
sherry
. Why
is it sweet? Because the addition of
brandy killed the yeast before the sugar was all used up.
A dry
sherry
is produced if fermentation is allowed to continue later before brandy
is added. Such a
a lighter, drier type is
called a fino
sherry
, such as amontillado and manzanillo, with higher alcohol of 19-21%.
Sweet
sherry
is oloroso, dry
sherry
is fino.