Wines Samenvattingen
Chapter 1; Managing in the Vineyard
A number of factors must be combined to get a good basic product:
- Good soil for the right variety of grape.
- A good climate and micro climate.
- A wine-grower with passion and expertise.
1. Climate & Weather
Wine growing is possible between the 30th and 50th degree of latitude (plaats op de wereld;
binnen bepaalde lijnen). Outside these climatice zones growing wine is not possible (blz: 10).
Climate categories
There are a number of climate categories. In Europe various climate zones are distinguished
(onderscheidend) starting with A to B and C1, C2 & C3, with A being the coolest zone and C3
the hottest. The figures correspond with legislation (wetgeving), stipulation (bepalen)
whether or not in a particular zone tartaric acid may be used or whether sugar mat be
added. Winker-index: new word classification.
Climate classification
Worldwide the climate is classified according to the following types:
Maritime climate: warm summers, mild winters, and the regions are cold due to larger
bodies.
Continental climate: region surrounded by land. Climate is cool.
Mediterranean climate: dry summers, mild winters, rainfall especially during winters.
Sub tropical climate: rainfall in summer, hot summers and little difference between summer
& winter.
Climate aspects
Overview of the most important climatic factors for growing wine:
Temperature: The temperature for growing wine is 10 °C below growing grapes is not
possible. Higher than 25 °C the vine stops growing. Grape varieties between 20 °C and 22
°C
Frost: by night frost the vine can freeze to death. The buds can be sprinkled by water to
make sure they don’t freeze.
Sunlight: Sunlight is needed for the process of photosynthesis. A vine needs 1500 hours of
sun to be able to produce ripe grapes.
Rainfall: A grape plant needs at least 700 mm of rain per growing season. Too much rainfall
can cause rotting; resulting in fungal diseases, rotting of the roots and the plant will die.
Rainfall just before or during the harvest (oogst) can result in a crop that is less
concentrated. Extra water can make a difference between no harvest and a good harvest in
some wine ereas.
Hail (hagel): can cause damage throughout the season.
,Wind: Regular wind has a favorable effect on the vine. Fungus (schimmel) is then less able to
affect the vines. Wind can also have negative effects on the vines.
Global warming: the average temperature has increased by o.0 to 0.6 °C in the past 100
years. Because of this; the upper limit of growing wine has moved up to cooler areas and so
there are more possibilities to use other varieties.
2. Soil and soil (bodem) composition
Soil depth plays an important role in the development of the root system of vines. If a deepl
soil has sufficient water reserve then this is ideal for the mass production of wine, in this
case the roots have to dig deep to get the minerals. When the soil is shallow (ondiep) and
has a limited water reserve then this contributes to qualitatively better grapes and better
wine. The reason for this is that the roots must work hard to get to the nutrients and
minerals. The harder the vine needs to work the better the quality of the wine.
3. The Vine
A vine is an upward-climbing shrub, also called Vitis Vinifera. 5000 grape varieties, 1000 of
them are used to produce wine. Intensive growing is mainly about money; i.e. producing
wine as fast and as cheaply as possible. The vineyards are then efficiently and logically
planted to get a maximum of grapes.
Growing organically is very popular now. The wine philosophy underpinning organic growing
is that the grape must be treated naturally, so that the juice from the grape is pure and
therefore contains only a few harmful substances.
Biodynamic growing is derived from the anthroposophical theory of Rudolf Steiner. This
theory divides nature into four elements: earth, water, air and fire. According to the
anthroposophical theory the vine consist of these elements:
- Earth the root system
- Water the leaf
- Air the flower
- Fire / heat the grape
Pruning & Training
To ensure a good crop each year the plants must be pruned (snoeien) and trained. Pruning
of the vine takes place in the rest period of the plant. In the growing season pruning also
takes place, this is called canopy management. Shoots or even young bunches of grapes are
cut away to give the remaining bunches more concentrate and a higher chance of ripening.
Below the most important pruning methods are described:
Guyot method:
When this method is used a short and long piece is left after pruning. This will result in a
higher yield, because most fertile buds will stay on the vine. Two varieties: single guyot, on
shoot remains and the double guyot method, on both sides of the vine, a shoot is left after
pruning. (Blz 13 voor foto’s)
Cordon pruning method
This method makes it possible for the vines to be at a large distance, with the advantage that
the leaves and bunches are well separated from each other to avoid fungal diseases.
,Bush vine or Gobelet method
This involves a free-standing vine, with a varying number of shoots, which are all pruned
back to about to buds.
4. Pest and Diseases
In addition to weather conditions there are also other threats for the vine.
Blz 13 + 14
Harvesting
The time of harvesting is very dependent upon the weather conditions during the year. By
using a refractometer the increase in sugar content of a grape can be measured day by day.
Harvesting can be done by hand or mechanically. By hand you can make a better selection.
Mechanically is cheaper.
Blz 15 t/m 18
Chapter 2; Managing in the wine cellar
Determining the time of harvesting is one of the most important moments in the whole
process. Sugar content should be as high as possible, while acidity must be sufficiently low.
1. The grape
A grape consists of various elements. The elements almost all play a role in the wine making
process:
o Stalks (Stengels) (tannin looizuur)
The stalks are often removed before the wine is made. The stalks contain a lot of green and
harsh tannin, which is not appreciated in modern wine making. It takes too long before
these tannins are broken down and before the wine is ready to drink. That is why the
bunches of grapes are destemmed before wine production.
o Seeds (bitter oils)
The seeds are very bitter. Therefore, the grapes are often gently crushed so as to avoid
getting tanning oil in the grape juice.
o Skin (colour, tannin, flavour)
The skin contains colour, or polyphenols, aromas, and tannin. If the skin is soaked during
alcohol fermentation then the wine will go red. If the skins are only soaked briefly and only a
little of the colour is transferred then the result is a rosé wine. The longer the skins ferment,
the more tannin or bitter substances will get into the wine. The higher the tanning content,
the longer a wine can be preserved and the higher the bitterness of the wine.
o Pulp (vruchtvlees) (water, sugar, acids, flavourings)
80% of a grape is grape juice or pulp. The colour of the pulp is transparent and will never be
able to give red wine without the effect of the skin. That is why white wine is made of the
pulp only. The amount of sugar per liter juice gives an indication of the possible alcohol
percentage in the wine. Each 16.5 gram of sugar per liter of juice produces 1% of alcohol.
The level of acidity of a grape varies between 4.5 and 8 grams per liter.
, Sugar can also be added, that is called chaptalization. If a grape lacks acidification is
sometimes permitted. De-acidification is done with grapes that contain too much acidity.
Tannin can be added if the young wine contains too little tannin.
o Yeast (micro organism on the surface of the skin)
Without yeast cells there would be no alcoholic fermentation and they are therefore
essential in wine-making. To make sure that fermentation will start, cultivated yeast is used,
which is added to the juice.
2. White wine production
- Harvesting (handpicked or by machine)
- Transport to winery (cool and fast to prevent oxidation)
- Crushing
- Pressing
- Alcoholic fermentation
- Filtering
- Maturation
- Bottling
Skin contact: skins will be soaked with the juice briefly at a temperature of 4 °C. This causes
extra aromas from the skin to be absorbed by the juice. One could also choose to press the
grapes at the same time. The juice, after clarification is fermented:
ALCOHOLIC FERMENTATION: YEAST + SUGAR ALCOHOLIC + CARBON DIOXIDE GAS (CO2) +
WARMTH.
Alcoholic fermentation is the conversion of the sugars, by means of yeast into alcohol and
carbon dioxide. Alcoholic fermentation takes place at a temperature of 14 to 20 °C. This
process takes two or three weeks. After fermentation the wine is pumped into clean tanks
and the dead yeast cells are left behind. Most white wines do not undergo malolactic
fermentation.
MALOLACTIC FERMENTATION = MALIC ACID LACTIC ACID
This is the conversion of the sour malic acid into the gentler lactic acid. The bacteria present
in the wine cause this process. Most white wine that is produced nowadays must be drunk
within two or three years after harvesting.
3. Red wine production
- Harvesting
- Destalking / crushing
- Alcoholic fermentation with skins & pips
- Malolactic fermentation
- Pressing
- Maturation & Filtration
- Bottling
