1. 1
CHAPTER 5 – FACTORS
INFLUENCING THE TASTE OF WINE

2. 2
CHAPTER 5 – FACTORS INFLUENCING TASTE
Contents
Seven main factors
influence wine quality:
1. Climate
2. Soil
3. Grape variety
4. Viticulture
5. Vinification
6. Annual weather
7. Ageing

3. 3
CHAPTER 5 – FACTORS INFLUENCING TASTE
Climate
 The main factors influencing climate are:
 Latitude
 Aspect (sun facing or not)
 Altitude
 Geographic features (rivers, lakes, hilltops)
 Main wine areas are 30 – 50
o
north and south of the equator.

4. 4
CHAPTER 5 – FACTORS INFLUENCING TASTE
Climate
 Climate can be defined by three elements:
 temperature
 rainfall
 sunshine
 The balance between these three factors
determines whether or not the vine can be
cultivated as well as the quality of the grapes
obtained.
 One should distinguish between the type of
climate in general and the climate of a particular
growth season, for instance the climatic profile of
a particular vintage.
e.g. a warm year in a cold climate...

5. 5
CHAPTER 5 – FACTORS INFLUENCING TASTE
Climate
 An average annual temperature above 10°C
 Rainfall of 500 mm per year
 1,000 hours of sunshine
 The vine requires little in terms of climate; there are very
few limiting factors:
 It is the period between flowering and harvesting that
ultimately determines the quality of the wine.
 Winter frosts (-25°C), spring frosts (-4°C), strong winds,
violent storms, and hailstorms can damage and even
destroy a vineyard.
 Where permitted, irrigation is used to make up the shortfall
in rain.

6. 6
CHAPTER 5 – FACTORS INFLUENCING TASTE
Climate
 Cold climates produce wines which are:
 acidic, pale, low in alcohol,
light and elegant.
 On the other hand, warm climates
produce wines which are:
 high in alcohol, deep in colour,
powerful, low in acidity, tannic.
 There are always exceptions to prove the
rule, i.e. wines said to be "atypical".
 Between these two extremes, a vast
panoply of styles is possible.

7. 7
CHAPTER 5 – FACTORS INFLUENCING TASTE
Soil
Influences from soil on grapes are:
 The soil’s physical properties
(drainage, granule size)
 The soil’s chemical properties
(availability of nutrients)
 The soil’s biological properties
(organic material and living organisms)
Rule of thumb:
 Poor soil gives low yields of quality
grapes (plant’s survival instinct).
 Rich soil gives higher yield of less good
quality grapes.

8. 8
CHAPTER 5 – FACTORS INFLUENCING TASTE
Soil
 Requiring little in terms of nutrients, a vine’s root system enables
them to survive easily by penetrating deep down.
 Vines are cultivated on many different types of soil:
 limestone and marl (Champagne, Chablis, Burgundy, etc.)
 clay (Petrus)
 pebbles, stones (Haut Brion, Chateauneuf du Pape)
 volcanic (Alsace, Switzerland, Sicily)
 sandy or sand-covered (Napa Valley)

9. 9
CHAPTER 5 – FACTORS INFLUENCING TASTE
Soil
 The nature of the soils is one of the
fundamental elements underlying the
concept of ‘typicity’ and the notion of
wine ‘terroirs’.
 Mineral and organic additives can only
partially alter the essential nature of the
soil.
 In terms of wine-making, soil, sub-soil
and grape varieties are the only
constant factors to be taken into
account.

10. 10
CHAPTER 5 – FACTORS INFLUENCING TASTE
Grape varieties
How grape varieties influence quality:
 Different varieties have different fruit
flavours, different ripening
characteristics and react differently to
climate and wine making techniques.
 Different rootstock offer advantages and
resistance to different pests and
diseases.
Skin
Stem
Pips
Pulp
The grape consists of a stem, skin, pulp, juice
and pips – all these play a part in the final
wine flavour:
Pulp and juice contribute fruit flavours, fruit
sugars and acid.
Stem, skin and pips contribute to tannins.

11. 11
CHAPTER 5 – FACTORS INFLUENCING TASTE
Grape varieties
Why use different rootstock ?
The vine louse phylloxera gradually swept through the vineyards
of Europe at the end of the 19th
century, literally destroying them.
The technique of grafting (European vines onto American
rootstock) resulted in the replanting of the vineyards within fifty
years.

12. 12
CHAPTER 5 – FACTORS INFLUENCING TASTE
Viticulture
 Viticulture (vineyard management) plays a vital
role towards fruit quality:
 Compromising between quality (low yields)
and quality (high quality fruit).
 Managing the vine’s growth cycle.
 Controlling unwanted pests and disease.
 Purposely encouraging botrytis cinerea
(noble rot) when making sweet wines.
 Choosing the optimal time to harvest.

13. 13
CHAPTER 5 – FACTORS INFLUENCING TASTE
Viticulture – The life cycle of
the vine
 The vine is a wild creeper which can
grow in any type of soil and virtually
any type of climate.
 A member of the genus Vitis, of the
variety Vitis Vinifera, its roots enable it
to thrive, thus its abundant vegetation
must be tamed in order to produce fruit
and not just leaves and branches.
 Since the advent of phylloxera (end of the 19th
century),
European vines are now grafted onto American rootstock.
 The vine is a rustic and hardy plant, but it requires great care
and attention in order to produce good quality fruit.

14. 14
CHAPTER 5 – FACTORS INFLUENCING TASTE
Viticulture – The life cycle of
the vine
 Once planted, the vine initially develops
its root system, then its shoots and
leaves.
 Beyond that age, it is a question of finding
the right compromise between quantity
(lower yields) and quality (the nature and
composition of the grapes change).
 The first fruits only appear in the third
year. The vine is a perennial plant that
can live a very long time, but the optimum
age for quality is when the vine is aged
between 7-25 years.

15. 15
CHAPTER 5 – FACTORS INFLUENCING TASTE
Viticulture – The rhythm of the
seasons

16. 16
CHAPTER 5 – FACTORS INFLUENCING TASTE
Viticulture – The annual growth
cycle
Winter End of winter Beginning of spring
Spring

17. 17
CHAPTER 5 – FACTORS INFLUENCING TASTE
Viticulture – The annual growth
cycle
Beginning of summer Summer
End of summer
Late harvesting or
vendanges tardivesHarvesting

18. 18
CHAPTER 5 – FACTORS INFLUENCING TASTE
Viticulture – Winter
 The pruning of the vine begins from the onset of the first hard
frosts at the beginning of winter: the vine is in a state of rest.
 Pruning has several objectives:
 bringing shape and order to the
vegetation
 limiting the development of the
plant
 controlling the production of
grapes
 prolonging the life of the vine, by
promoting new growth.

19. 19
CHAPTER 5 – FACTORS INFLUENCING TASTE
Viticulture – Spring
 The warming of the soil prompts the vine to burst into bud.
At this time of year, the buds and young leaves are very
fragile and susceptible to the ravages of frosts in colder
climates.
 The first leaves appear.
 At the end of spring, the first
inflorescences (bunches) are
visible and develop whilst waiting
to blossom.

20. 20
CHAPTER 5 – FACTORS INFLUENCING TASTE
Viticulture – Summer
 The flowering results in the creation of berries.
 Warm dry weather conditions are required to
obtain optimal results: in their absence, the yield
of the vine is dramatically reduced as a result of
millerandage (poor berry set-up) or coulure
(shatter), poor or abnormal fruit set.
 The grapes grow larger and develop pigment
(véraison).
 Leaf growth is trimmed and managed in such a
way to obtain the largest leaf surface area
possible, in order to optimise photosynthesis and
the development of sugars in the grape.
 Depending on the climatic conditions, the threat
of attack by diseases and insects is ever present.

21. 21
CHAPTER 5 – FACTORS INFLUENCING TASTE
Viticulture – Autumn
 The harvest takes place at the end of summer or
the beginning of autumn, depending on latitude
(September/October in the northern hemisphere,
March/April in the southern hemisphere). The
date is chosen according to the maturity of the
grapes.
 The grapes are harvested by hand or by
machine.
 The fall of the leaves marks the end of the
active period as the vine prepares to enter
its period of rest.
 In the case of late harvesting or
vendanges tardives, the grapes are picked
in a state of over-ripeness in order to
obtain high concentrations of sugar.

22. 22
CHAPTER 5 – FACTORS INFLUENCING TASTE
Vinification
 Vinification (the art and science of wine making) plays an important
role in the final flavours and balance of the wine:
• Different extraction and fermentation
techniques will result in different levels of
tannins, colour, alcohol levels and residual
sugars.
• Different post-fermentation treatments
provide different results in terms of acid
balance, tannins, colour and flavour
balance.

23. 23
CHAPTER 5 – FACTORS INFLUENCING TASTE
Vinification stages
• Stage 1 – Treatment of the grapes
immediately after harvest and before
fermentation.
• Stage 2 – Crushing and pressing the
grapes
• Stage 3 – Fermentation
• Stage 4 – Choice of fermentation
vessel
• Stage 5 – Other processes
• Stage 6 – Treatments after
fermentation
• Stage 7 – Maturation
• Stage 8 – Finishing and bottling

24. 24
CHAPTER 5 – FACTORS INFLUENCING TASTE
Vinification – Red wine-making
Red grapes
Destemming
Stems
removed
Roller
crusher
Addition of
sulphur dioxide
Grape harvest de-
stemmed and crushed
Pump
Fermentation vat
Must at 30°C
Pump
Cooling liquid
Cooling liquid
Cold water
Cooling
Must cooled to 25°C
Remontage
Marc
Must
Spraying of
the marc cap

25. 25
CHAPTER 5 – FACTORS INFLUENCING TASTE
Vinification – White wine-making
Fouloirs à
rouleaux
Whole white
grapes
Press
Pump
Pompe
Pump
White grapes
Racking tank
Deposit of
solids
Fermentation tank
Temperature
18-20°C
Temperature control
Draining
Crusher
Addition of
sulphur
dioxide

26. 26
CHAPTER 5 – FACTORS INFLUENCING TASTE
Vinification – In search of
colour Extraction of polyphenols (colour + tannins).
 Colouring matter: flavins (white wines) and anthocyanins (red
wines) are naturally present in the grapes.
 The tannins (red wines only) are found in the skin, the pips and
the stem of the grape. They are responsible for the astringent
sensation when tasting wine.
 Their concentrations change, depending on the ripeness of the
grapes (yields), the age and the state of health of the vines.
 The duration and the temperature of the maceration affect the
concentration of the tannins and anthocyanins.
 The polyphenols, produced naturally, help protect the wine
(antioxidants).

27. 27
CHAPTER 5 – FACTORS INFLUENCING TASTE
Vinification – In search of
colourColouring
intensity
Sangiovese
(Tuscany)
Nebbiolo
(Piedm
ont)
G
am
ay
(Beaujolais)
PinotNoir
(Burgundy)
Tem
pranillo
(Spain)
Syrah
(Rhône
valley)
Cabernet-sauvignon
(Bordeaux)
M
albec
(Argentina)
M
erlot
(Bordeaux)

28. 28
CHAPTER 5 – FACTORS INFLUENCING TASTE
Annual weather conditions
Perfect conditions would be:
• A cold winter – inhibit growth, rest the vine, frosts to kill diseases
(but not the vine), rain for moisture reserves
• A warm spring with gentle rain for growth, warm settled period
after flowering
• A hot summer with a little rain to swell the fruit
• A fine, dry autumn to complete
ripening and for the vintage.
Main climatic dangers from spring
until harvest (early autumn) are:
• Severe frost.
• Hail.
• Strong wind.

29. 29
CHAPTER 5 – FACTORS INFLUENCING TASTE
Ageing
 Colour
 Aromas
 Taste
 Other aspects
 Balance of the wine

30. 30
CHAPTER 5 – FACTORS INFLUENCING TASTE
Ageing – Red wines
Aged wine
hints of orange/brown
fully mature
Tannic wine
dark red, garnet
coloured, maturity
Young wine
vermillion/purple
cold regions

31. 31
CHAPTER 5 – FACTORS INFLUENCING TASTE
Ageing – Red wines
Grape variety Young Mature Fully mature
Cabernet
Sauvignon
Pepper, blackcurrant Leather, cinnamon,
cloves,mushrooms
Truffles, spices
Cabernet
Franc
Red fruits, pepper,
vegetal notes
Leather, mushrooms Spices
Merlot Raspberries, red
currants, blackberries
Leaf mould, leather,
moss, tobacco
Leather, truffles
Pinot Noir Cherries, blackcurrant,
raspberries, strawberries
Humus, mushrooms,
roses
Leather, game,
fruits in alcohol
Syrah pepper, violets
blackberries
Spices, leaf mould,
liquorice
Truffles, mild
spices, humus
Depending on the type of wood and the length of maturation,
the perception of notes of vanilla will be more or less intense.

32. 32
CHAPTER 5 – FACTORS INFLUENCING TASTE
Ageing – White wines
Young wine
grey-green tints aged
in stainless steel vats
Mature wine
yellow with hints of
gold matured in wood
Mature sweet wine
strong golden yellow
very mature

33. 33
CHAPTER 5 – FACTORS INFLUENCING TASTE
Ageing – White wines
Grape variety Young Mature Fully mature
Sauvignon Gooseberry,exotic fruits,
citrus fruits
Smokey, silex, box
wood, lime blossom
Chardonnay Lime blossom, acacia,
honey, white flowers
Broom, heather,
butter
Hazelnuts, toasted
almonds, honey
Semillon Grapefruit, lemon,
acacia
Honey, wax Toast, coffee, butter
Riesling Exotic fruits, pineapple,
cinnamon, lemon
Apricot, peaches,
honey
Gingerbread,
hydrocarbons
Depending on the type of wood and the length of time aged, perceived
notes of vanilla will be more or less pronounced.

34. 34
CHAPTER 5 – FACTORS INFLUENCING TASTE
Ageing – Other changes
 The tannins polymerise to a greater or lesser degree,
forming a deposit in the bottle which requires decanting.
The sentation of astringency fades with age.
 The perception of acidity also changes in the same way,
creating more supple, well rounded wines, when mature or
fully mature.
 The sugar and alcohol content is more stable, any
perceived differences are solely the result of changes in
acidity and tannins.