Bordeaux Wine Guide: Osmosis & Extraction

[Matthias R WHT]

Having examined the appellations of the Médoc, from the grand chateaux
of Margaux just north of Bordeaux, right up to the less glorious but
nevertheless vital estates of the Bas-Médoc north of St Estèphe, I
thought it was time for an interlude. A chance, perhaps, to look at
some of the wider issues for Bordeaux, rather than continuing the
usual appellation run-down that so many wine guides seem to proffer. I
have chosen what is perhaps a rather provocative title for this
section of my guide, for the presence of the words extraction and
osmosis at the head of the page, in large font, perhaps suggests that
these activities are responsible for absolutely all the woes that I
discuss below. This is not, in fact, my intention, but they almost
certainly play an important role in Bordeaux today, in some wines at
least, at some chateaux.

The issue that is up for discussion is one of style. Take a broad
selection of wines from Bordeaux, from recent vintages, and through
tasting them - even if you were completely blind to the identity of
the wines - I suspect you would soon conclude that you were tasting
the wines of the Gironde. Do the same with some mature vintages, from
the 1960s or 1970s, perhaps, when there were a few decent vintages (as
well as a good number of stinkers) to choose from, and I suspect the
experienced taster would come to the same conclusion. Both eras
yielded wines that are readily identifiable as Bordeaux, and yet it is
argued by many that the wines are not of the same style. I will be the
first to admit that it is difficult to judge when comparing mature
Bordeaux to the same wines in their first flush of youth; I do not
have the ability, or experience, or is it just a sense of nerve to
extrapolate backwards from tasting mature wines today. Does anybody
have this ability? Nevertheless, many people who have been drinking
Bordeaux for more than a decade or two maintain that the wines today
are very different to the wines of yesteryear. This is not something
that can be denied, I feel. What is open to debate, however, is
whether, firstly, this is a change for the better or for the worse
and, secondly, why have the wines changed in this manner?


The New Bordeaux

Those who argue that this is a change for the better may put forward a
number of very strong points in support of their case. In particular,
the increasingly widespread availability of good quality wines from
across all appellations of Bordeaux, at all levels, rather than from
just a few famous and yet occasionally irregular names. It is a hard
argument to refute; the wines are more reliable, they say, more
dependable, more predictable in terms of the experience that they will
provide. The flavours are clean and fruit-rich, rather than the
occasionally dirty and questionable character of more ancient wines.
They are textured, rich, may we suggest even hedonistic? Compared to
the wines of decades long since disappeared, dilute efforts that they
were, weak in colour and character, thin and emaciated, today's wines
seem to win hands down. This is the stance the advocates of the New
Bordeaux will take. They prefer the modern wines, fleshy and
concentrated beverages, approachable from the moment the firing pistol
is started, only closing down for an optional awkward moment, a
fleeting phase sometime during the first decade. Scour the wine forums
of the internet and you will find Bordeaux from every recent vintage
available at retail being 'popped and poured'. Much of this activity
is valuable research, of course, but it is also a new way to enjoy
Bordeaux. Many of those who remember the wines of long past decades
admit that the wines were not so approachable in their youth then;
they were lighter, in terms of alcohol, and they were perhaps less
well stuffed, less endowed with new oak, than the wines of today. And
they were perhaps more tannic, or at least the tannins were more
obvious in their youth. But they evolved into fabulous, dry, savoury,
food-friendly wines, a style that for some drinkers epitomised the
region, in fact they were the very raison d'être of wine. And it is a
style that some fear is rapidly vanishing - or has perhaps already
disappeared.


Natural or Unnatural?

Accepting that Bordeaux has changed, is this a natural phenomenon, one
that is perhaps inevitable, or is it solely due to the hand of man? If
a natural development, what processes may be playing a role in the New
Bordeaux? And, perhaps more importantly, if the change in style is due
to human intervention, what less-than-natural technologies are being
employed today which were not in place twenty or thirty or more years
ago?

When looking for a natural explanation for the New Bordeaux the
obvious culprit is climate; it seems very likely indeed that global
warming must have some part to play here. It is not as clear cut here
as it is in some other regions, such as the Southern Rhône, which
apart from the washout of 2002 has had success after success with the
early vintages of the 21st Century, but nevertheless Bordeaux has
certainly seen a number of prodigious vintages in recent years. An
obvious choice is 2005, a great vintage which is surely on a level
with 1961 and 1982, but there is also 2000, another reason for the
Bordelais to celebrate, and of course 2003. The latter may not have
been universally successful, but it is impossible to deny that it was
hot.

The Bordelais do not deny the influence of climate change on Bordeaux.
Speaking in February 2008 at a vertical tasting of his wine, Mouton-
Rothschild director Hervé Berland informed his audience that
temperatures in Bordeaux are today, on average, 1ºC higher than during
the last 40 years. The changing climate brings less summertime
rainfall, which he feels is beneficial for the wines provided the
drought is not so serious as to impair the health of the vines, and
that the water table is maintained by rainfall during the other
seasons. In fact, Berland seemed somewhat unfazed by rising
temperatures, but cited other freak weather conditions, such as
unseasonal hail or frost, as potentially more damaging and a more
pressing concern. Nevertheless, Berland's optimism was not
unassailable; he concluded that although Bordeaux has benefited from
climate change so far, if the change is extreme it may alter the face
of Bordeaux beyond recognition. He even went as far as to suggest
climate change would push vignerons towards different grape varieties,
but I find the concept of the INAO approving Mourvèdre and Syrah
(these are my thoughts, not Berland's) for planting on the Médoc very
unlikely. Nevertheless, these statements do seem to indicate that the
Bordelais - some at least - accept that climate change is influencing
the style of the New Bordeaux. But it is not the whole story.


Unnatural Interventions

Without doubt there have been many recent influences on Bordeaux other
than climate change. These are what we might term unnatural
phenomenon, evidence of human intervention. This is not to say, of
course, that such actions are inherently inappropriate; after all, all
wines are the produce of intervention. The very processes of pruning
and training - universal, essential vineyard practices - can be
regarded as a manipulations on the eventual quality of the fruit of
the vine, and thus of the final wine. The difficulty comes with
teasing out which practices are essential and which not, and which
practices are aimed at improving quality and which are aimed at a
certain style of wine, one that for some does not typify Bordeaux. I
suspect, however, that it is impossible to draw well defined
divisions; quite simply, many practices have an effect on both quality
and style.

Today Bordeaux is still in a recovery phase; the last century or so
has seen replanting after phylloxera, global war, economic depression
and further replanting after the devastating frost of 1956. Many
vineyards and estates suffered, and so did the quality of the wines.
But today, boosted by greater, more global interest in the wines of
Bordeaux, there is more investment in the region, and the last few
decades have seen frenzied activity in the vineyards. At last there is
capital for replanting and retrellising, as I have seen at Chateau
Preuillac, where whole vineyards were being cleared and replanted with
more suitable varieties, at a different planting density, on a new
trellising system. Alongside new vineyards comes new expertise,
individuals with a better understanding of the science of viticulture,
and a closer attention to detail. Practices that are now widespread
were once regarded as madness, but today few would deny the beneficial
effects of green harvesting, removing bunches of fruit before they
ripen to ameliorate the quality of those bunches that remain. On other
practices, however, perhaps we are less certain; at many estates you
will find workers leaf stripping and bunch thinning, to expose
ripening fruit to the sun. And in some cases the hangtime is
prolonged, the fruit left on the vine as long as possible to reach
maximal ripeness, removing any chance of green flavours, but also
changing the style of the eventual wine. Later picking, for instance,
may well result in fruit with lower acidity, which will have a clear
and tangible effect on the finished product, shifting it away from the
more austere style of yesteryear.

In the chai there is similar investment; traditional equipment, such
as the wooden basket press to the left, pictured in the grounds of a
château in the Entre-Deux-Mers, has been superseded by newer designs.
Pneumatic presses and stainless steel water-cooled fermentation vats
are now the norm, although a few estates do cling onto oak or even
concrete vats. And with new equipment comes new methods. Destemming
the fruit reduces stalk-derived characteristics, and how the wine is
worked in the vat can have a marked effect; a long maceration
increases extraction of colour and tannins from the grape solids.
There are many wines of Bordeaux today exhibiting the effect of over-
extraction; dark wines in possession of huge walls of tannin towering
over the fruit, and their spiritual home seems to be on the right
bank. I find them undrinkable and with an uncertain future, and yet I
see wines I consider to be over-worked receiving high marks from other
tasters on wine discussion forums, and indeed from established
critics. Clearly, one man's meat really is another man's poison.

This episode in my guide to Bordeaux does not pretend to be an
exhaustive guide to all the new techniques and technologies that may
play a role in Bordeaux today; to provide such detail would require a
whole book (and indeed there are books on such topics available).
Nevertheless, it is worth looking at one or two of the perhaps more
incongruous practices to illustrate what the Bordelais are doing today
that they were not doing 50 or 100 years ago. Extraction we have
already discussed; clearly an essential element that has always had a
part to play in the winemaking process, it is the inappropriate
extreme to which extraction is taken by a handful of producers that so
markedly influences the wine. Other techniques, however, are
completely new to the region, or indeed new to winemaking altogether.
The aim of many such techniques is to increase the concentration of
the wine, a process in which principally water is removed. The desire
to complete such a task is perhaps understandable; with such a
technique, nature's failings may perhaps be corrected. Dilute musts
from a wet harvest, the fruit swollen by an abundance of rain, may be
returned to their rightful state. There are any number of methods by
which this achieved, but they focus around three core techniques;
boiling, freezing or molecular filtration.


Boiled, Frozen or Filtered?

The first of these three methods is low pressure evaporation; here the
must is held under vacuum, and under such low pressures the water in
the must will boil off at much lower temperatures than is otherwise
the case, the usual boiling point for water being about 100ºC at a
pressure of 1 atmosphere. Rapid evaporation of water at a temperature
of 20ºC in theory does no harm to the wine as this temperature is no
higher than that achieved during fermentation, although there is
surely a risk of volatile substances other than water evaporating from
the wine under such conditions. The technique also requires the
installation of some very expensive equipment. If we were to look for
a parallel but perhaps more natural process, the method is analogous
to traditional production techniques utilised in Italy, particularly
Valpolicella, where grapes are dried in warm, ventilated rooms. Both
evaporation and its natural analogy are manipulations, although the
latter has been in use for centuries (which doesn't automatically make
it 'right') whereas the former is a much more recent practice (and
this doesn't automatically mean it is 'wrong'), but neither
traditionally have a role in Bordeaux.

Freezing is another method utilised to reduce water content, and here
the natural analogy is the process of making eiswein, where frozen
berries are harvested and pressed in extreme weather conditions to
facilitate the separation of the sugar- and acid-rich juice from the
frozen water crystals, thus increasing the concentration of the wine.
In the winery the technique is known as cryo-extraction, and it was
developed by Jean Merlaut, of Chateau Rayne-Vigneau, in conjunction
with Professors Chauvet and Sudraud from the University of Bordeaux
and the newly installed regisseur Patrick Eymery. The technique as it
is used in Bordeaux, particularly in Sauternes, is perhaps more a
response to the climate and the condition of the grapes at harvest,
rather than an attempt to imitate the eisweins of Germany, although an
increase in sugar contencentration is certainly one effect. Botrytis
cinerea, the cause of noble rot, requires very specific conditions,
and with a damp harvest there is a danger that the beautifully
shrivelled and sugar-rich berries will turn to grey rot, and that
quality will be reduced or even ruined altogether. This was a
particular problem with the 1982 harvest, and Jean Merlaut agreed to
some trials of freezing the berries in order to remove water, leaving
only the rich, botrytised juice, thereby potentially eliminating the
problem of a wet harvest and the swollen, water-logged grapes that
result. Naturally, however, the process has its problems and also its
detractors, who claim that concentration in this way will only
accentuate the flaws already present in the wine, a reasonable
argument. Nevertheless, today it is a method accepted and utilised by
many chateaux in Sauternes, not just Rayne-Vigneau.

Finally, modern techniques allow for the removal of water from must
using methodologies that depend on molecular size. The method, reverse
osmosis, has gained some notoriety as being the ultimate in
manipulation; unlike cryo-extraction and low pressure evaporation,
there is no natural analogy. As the name suggests, the process is the
opposite of osmosis, a process whereby osmotic pressure (which is a
result of the concentration of solute, meaning anything dissolved in
the water) on either side of a water-permeable membrane forces water
to move from one side, the side of low concentration, to the other,
the side of high concentration. In reverse osmosis a new physical
pressure is introduced to the high concentration side, which forces
the water in the opposite direction. The process has been used for
many years to produce drinking water from seawater, the pure water
forced by pressure through the permeable membrane whilst the salty
solute remains within. The same process may be applied to wine, but
here the water obtained is a waste product, it is the increasingly
concentrated wine that remains which is the final and desired product.
As you might imagine, the pressures required to drive water through
the membrane may be considerable. It is a technique which, like those
above, may concentrate flaws just as readily as flavours, nevertheless
it is rumoured to be in wide use in Bordeaux. The image of a reverse
osmosis machine, above, was snapped in a dark (hence the poor quality
of the image) anteroom in the chai of a well-known Bordeaux chateau.
Despite the frequent denials, many regisseurs are in fact putting
these technologies to use.

That these techniques are in use is undeniable. That climate change is
happening, and that it is having an effect on the vineyards of many
European wine regions seems, to me at least, to also be undeniable. I
think that the effect on the wines of Bordeaux is certain; the wines
today are different to the wines of just a few decades ago. Whether
this is regarded as a problem, however, is down to the individual and
his or her palate. Some wines that are coming out of Bordeaux today
are superb, but it is not so much a question of quality, but rather a
question of style. A shift towards this new rich, concentrated, fleshy
and textured style is often described as Parkerisation, a conscious
shift in the style of the wines towards one deemed to be desirable to
the critic Robert Parker, the most influential critic of the wines of
Bordeaux that the region has ever seen. There is of course no proof
that this is true, no-one to publicly confess that they have changed
their wines for Parker, and there are plenty who decry the theory as
nonsense. Whereas it is certain that the blame for climate change does
not lie at his feet, we must nevertheless acknowledge that - because
Parker points can bring great financial reward - in some cases at
least, the Parker effect must play a role. What will happen with
Parker's retirement (should that ever happen), or as he hands over the
reins of The Wine Advocate to his ever-burgeoning team of writers,
will be fascinating to observe.

In the next instalment we will return to the vineyards, and to the
right bank, a region where Parker is very much at home. First, St
Emilion, and then Pomerol.



- Wine Doctor.