Monday 18 May 2009

Types of Wine – How External Factors Can Affect Your Wine

The components that influence how a type of wine develops fall
broadly into two categories. The more `internal' factors are
things such as the variety of grape, the amounts of sugar and
the tannin that can be extracted. More external factors are the
yeasts, growing conditions, barrels and so on. Whilst it cannot
be argued that the principal influence is the combination of
grapes these external factors cannot be ignored.

The difference between grape juice and wine is alcohol which is
created by yeast fermentation. In many types of wine the yeast
itself is actually a factor in the flavor and the strain of
yeast certainly affects the amount of alcohol. Most yeast
naturally dies off at certain levels of alcohol bringing a
natural end to the fermentation, some like Tokay yeast, have a
higher tolerance and so make stronger wines. When the yeast dies
off and fermentation is complete the wine is still cloudy and
full of dead cells. There are many different methods of removing
these and they also have an effect on the flavor of the wine.
Racking, where the clear wine is drawn off after the yeast has
settled to the bottom is one. Some wines are deliberately left
on the lees, the dead yeast cells, because this gives them a
richness and depth of flavor - Champagne is a classic example of
this and it is what gives the wine that delicious toasty aroma
and taste. Muscadet Sur Lie is another example of this technique
and you can taste the difference between the lighter wines that
have been racked off and those that have not - it is quite
astonishing. Most yeasts occur naturally and fermentation will
start on its own, but sometimes if a wine maker is trying to
create something quite specific a starter yeast may be used.
However this can be fraught with dangers in terms of bringing in
unnatural flavors such as the 'Banana Beaujolais' that was
prevalent some years ago.

Botrytis or Noble Rot has a dramatic effect on the sugars in
the grapes and consequently on the wines produced from grapes
that have been affected by this benign fungus. It is prevalent
in areas where there are large bodies of water that produce
morning mists that are burnt off by afternoon sun. Day long
mists produce gray rot which is altogether less pleasant.
Sauternes, in Bordeaux is probably the best known area for
botrytised wines. The grapes affected by botrytis are shriveled
and look quite unpleasant but they produce the most fabulous
sweet dessert wines. The fungus reduces the water content in the
grapes making the sugars and the flavors far more highly
concentrated. The grapes are generally hand picked at just the
right stage which can involve as many as ten picking sessions to
get the maximum amount of grapes at just the right point. The
wines are generally aged for many years and have a rich, almost
unctuous texture and flavor that is unique. The wines are highly
prized and very expensive. They are not to everyone's taste but
I have to confess to a personal passion for them.

Without alcohol wine would not exist, it would merely be the
juice of grapes. The amount of alcohol is dictated by the sugars
in the grapes and the yeast used to ferment the juice. Wines
from cooler climates often have less than 10% abv (alcohol by
volume). The types of wine produced in warmer climates can have
much higher percentages of alcohol, often dictated by the yeast
used. There is a tendency for wines to be made with an abv of
14% or more, however the alcohol can completely overpower the
wine itself and all you can taste is the alcohol 'burn', they
should certainly not be drunk without food. The control of
fermentation is where many winemakers display their skill, hot,
rapid fermentation produces a very different wine to a cooler,
more controlled process. If a winemaker wishes to protect the
delicate fruit flavors of a wine such as Viognier, then
temperatures must be carefully controlled or all its subtleties
will be lost.

Of the external factors that affect the flavor of many types of
wine, Oak is probably the most widely debated. Some wines are
fermented in oak, or just stored in oak for a few months but it
will always have an effect. Additionally the type of oak will
produce completely different flavours. The effect of French Oak
is harsher when young, emphasizing the tannins, but becomes
buttery with age. American Oak is far more redolent of Vanilla
and spice. Russian Oak is not dissimilar to French but is not
yet as widely used. As well as the origin of the oak, there is
the question of 'old' or 'new'. Old oak barrels will impart some
of the flavors of the previous wine and be mellower than new,
some barrels are even 'toasted' to give yet a different set of
flavors. Oak is not the only wood used for barrels, though it
does have the most dramatic effect. One of my favorite wines,
from Chateau Marie De Fou in the Vendee is aged in Acacia
barrels and has truly unique and distinctive characteristics.
The difference between oaked and unoaked wines is probably best
demonstrated with Chardonnay - there are those that say it is
dead without Oak and those who won't touch it with Oak. It is
very much a matter of personal preference.

All types of wine are affected by many things other than these
basic internal and external components, and each will have a
different effect depending on the type of grapes that have been
used in the first place. Most of us start from either the grape
variety or the region from which it came, but why not try
following a more subtle thread in your choice of wine such as
the difference between French and American Oak. These minute
differences in types of wine can lead to some stunning
discoveries and increase your enjoyment of the wines you drink.

About The Author: Brought up in a family of Wine Lovers Chloe
Alster has a broad ranging interest in many types of wine, it's
cultivation, and history as well as the more social aspect of
wine appreciation. Her views and opinions are well respected
within the ranks of fellow enthusiasts. She writes extensively
on Wine related topics at where you
can read more about the components of wine mentioned in this

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