Chapter 5 - Factors influencing taste (NXPowerLite)

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CHAPTER 5 – FACTORS INFLUENCING THE TASTE OF WINE

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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

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Climate The main factors influencing climate are:

Latitude Aspect (sun facing or not) Altitude Geographic features (rivers, lakes,

hilltops) Main wine areas are 30 – 50o north and south of the

equator.

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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...

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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.

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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.

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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.

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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)

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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.

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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

PulpThe 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.

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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.

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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.

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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.

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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.

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Viticulture – The rhythm of the seasons

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Viticulture – The annual growth cycle

Winter End of winter Beginning of spring

Spring

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Viticulture – The annual growth cycle

Beginning of summer Summer

End of summerLate harvesting or vendanges tardivesHarvesting

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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.

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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.

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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.

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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.

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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.

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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

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Vinification – Red wine-making

Red grapes

Destemming

Stems removed

Rollercrusher

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

Rem

on

tag

e

Marc

Must

Spraying ofthe marc cap

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Vinification – White wine-making

Fouloirs àrouleaux

Whole whitegrapes

Press

Pump

Pompe

Pump

White grapes

Racking tank

Deposit ofsolids

Fermentation tank

Temperature18-20°C

Temperature control

Draining

Crusher

Addition of sulphurdioxide

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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).

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Vinification – In search of colourColouring

intensity

Sangi

oves

e

(Tus

cany

)

Nebbi

olo

(Pie

dmon

t)

Gam

ay

(Bea

ujol

ais)

Pinot

Noi

r

(Bur

gund

y)

Tem

pran

illo

(Spa

in)

Syrah

( Rhô

ne v

alle

y)

Caber

net-s

auvi

gnon

(Bor

deau

x)

Mal

bec

(Arg

entin

a)

Mer

lot

(Bor

deau

x)

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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 springuntil harvest (early autumn) are:• Severe frost.• Hail.• Strong wind.

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Ageing

Colour

Aromas

Taste

Other aspects

Balance of the wine

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Ageing – Red wines

Aged winehints of orange/brown

fully mature

Tannic winedark red, garnet

coloured, maturity

Young winevermillion/purple

cold regions

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Ageing – Red winesGrape variety Young Mature Fully mature

CabernetSauvignon

Pepper, blackcurrant Leather, cinnamon,cloves,mushrooms

Truffles, spices

CabernetFranc

Red fruits, pepper,vegetal notes

Leather, mushrooms Spices

Merlot Raspberries, redcurrants, blackberries

Leaf mould, leather,moss, tobacco

Leather, truffles

Pinot Noir Cherries, blackcurrant,raspberries, strawberries

Humus, mushrooms,roses

Leather, game,fruits in alcohol

Syrah pepper, violetsblackberries

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.

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Ageing – White wines

Young winegrey-green tints agedin stainless steel vats

Mature wineyellow with hints of

gold matured in wood

Mature sweet winestrong golden yellow

very mature

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Ageing – White wines

Grape variety Young Mature Fully mature

Sauvignon Gooseberry,exotic fruits,citrus fruits

Smokey, silex, boxwood, lime blossom

Chardonnay Lime blossom, acacia,honey, white flowers

Broom, heather,butter

Hazelnuts, toastedalmonds, 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.

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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.

Chapter 5 - Factors influencing taste (NXPowerLite)

Documents

taste climate climate

main factors

taste of wine

constant factors

limiting factors

taste soil influences

terms of climate

taste climate cold climates