THE BORDEAUX CLIMATE AND WINEMAKING
The Bordeaux climate could be classified as oceanic-temperate, with
moderate temperatures in both winter and summer. There are on average
2,000 hours of sunshine per annum. The nearby Atlantic Ocean has a
major effect on the difference between day and night
temperatures. Cool nights in the summer help to keep acidity levels in the
grapes high, also helping ensure that they stay healthy. Cool night-time
temperatures also have an important effect on the aromas and flavours
produced in the grapes.
The Weather
As the weather warms up in March or April the buds on the vines start
to burst. At this time of the year frosts can be a problem. In 1991, a
large part of the crop was lost due to temperatures as low as -7
degrees Celsius in mid-April.
Annual rainfall is about 700-800 mm. Summers are often sunny and dry,
the weather is normally very pleasant, although temperatures have been
known to reach 40 degrees Celsius!
Excessive or untimely rain and other problems like hail (especially in
spring and summer) cause more harm as the growing season
progresses. Rain during the later stages of the growth cycle is not
desirable because the roots carry water directly to the grapes, thus
diluting the final wine. However, this depends on the type of soil. Gravely
soil allows rainwater to drain away very quickly, whereas clay-based
soil retains water. At this stage, moist soil can encourage nearly
ripe grapes to rot.
A particular problem is hailstorms, which can wipe out the whole crop
in minutes. The hailstones can easily be as big as eggs - damaging
more than just the vines. Hailstorms are very localized, so
generalizations should not be made about their effects throughout a
given region or vintage.
The ideal weather for harvesting is dry and slightly windy. The wind
helps evaporate the morning dew and the grapes can be gathered in
perfect condition. Moisture and rain not only cause grapes to become
diluted, but water can also cause grey rot. Great wine can only be
made from first class grapes and so quality-conscious viticulturists
try to do everything they can to avoid rot and produce top quality
grapes. Hand picking will allow us to only process the healthy
grapes. Rain, however, causes many other complications to the vintage
routines, too.
It must be said as well that global climatic change seems generally to make
the weather conditions and waterfall more variable from one year
to another.
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