Caballero B. (ed.) Encyclopaedia of Food Science, Food Technology and Nutrition. Ten-Volume Set

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Vintage

Transportation Acceptance weighing

Press

Stems

Stemming crushing

Heating crushed grapes

Heating crushed

grapes

Fermentation on skins

Pomace

Centrifugation

20 8C 40 8C

Yeast

Secondary fermentation

Malolactic fermentation

Cask aging

Stabilizing

Racking

Clarification Fining

Sulfiting

Bottling

Ready for

bottling

Alcoholic fermentation

Close Filtration

Rose wine

Yeast

Fermentation on skins

fig0002 Figure 2 Flow sheet of processing rose

and red wines according to Troost G (1988) Technologie des Weines, 6th edn. Stuttgart:

Eugen Ulmer. (1) Acceptance of grapes; (2) stemming, crushing; (3) heating crushed grapes; (4) pressing; (5) centrifugation; (6)

fermentation on skins; (7) alcoholic fermentation; (8) malolactic fermentation; (9) clarification; (10) racking; (11) fining; (12) sulfiting:

(13) ready for bottling; (14) sterilizing filter; (15) bottling.

WINES/Production of Table Wines 6199

heater by means of a smooth-action pump (3). In

this process, which is also termed plasmolysis, the

semipermeable, cytoplasmic membrane becomes

permeable to the dissolved substances.

0032 Heaters for crushed grapes consist of a system of

tubes in a steam-heated room. It has been established

that heating the crushed grapes to 45–55



Cis

adequate to obtain dark-colored musts. Nowadays,

it is common practice to heat the crushed grapes

above the plasmolysis temperature to about 87



for a brief period in order to inactivate the enzymes

inherent in the fruit, and to kill off the microorgan-

isms. Subsequently, the crushed grapes are cooled to a

moderate temperature.

0033 The pretreated crushed grapes can now be

conveyed directly into a press (4) or into a straining

bin. After heating, processing is identical to that

described for white wine. The use of selected yeasts

for initiation of the fermentation process is strongly

recommended.

0034 After the alcoholic fermentation, the red wines are

developed in the same way as white wines, but with

the difference that the malic acid is degraded to lactic

acid almost completely (8). This ‘second fermenta-

tion’ is brought about by the activity of lactic acid

bacteria, but this frequently happens a number of

months after the alcoholic fermentation.

Development

0035 After fermentation of the must, which may have been

ameliorated or whose acidity may have been adjusted,

numerous processes take place in the young wine. It

develops to a peak, termed maturity. This aging and

finishing process takes place in a tank or in the bottle.

If the maturity peak is exceeded, the wine becomes

‘firne,’ which can still be considered a positive quality

characteristic. However, if this development con-

tinues, the wine will develop a rancid taste and

become ‘maderized’ and oxidized – a sign of rapidly

decreasing quality.

0036 The finishing and aging processes can be influenced

to a certain extent and for this reason one often talks

of ‘developing’ the wine. This involves treating the

wine with the aim of supporting the natural matur-

ation and clarification processes, and to protect the

wine from undesirable changes.

Racking

0037 The first step in the development of wine in the cellar

is racking (10, 10). By this is meant the separation of

lees from the wine by decantation.

0038 Despite racking, visible fine lees can still be sus-

pended in the wine; in any case, the wine contains

invisible colloidal dissolved substances. If the

beverages are to be limpid and clear when bottled

and sold, they must be clarified. This can be done

by centrifugation or filtration. Before filtration,

beverages are usually treated with fining agents,

i.e., a portion of the substances to be separated

out are flocculated, which improves the filtering

efficiency. This treatment is denoted preclarification

and fining of the wines (11, 11). (See Filtration of

Liquids.)

Fining

0039The invisible particles present in the wine consist

largely of polymeric carbohydrates, proteins ac-

counting for 10–20%, and oxidized and condensed

polyphenols making up the rest. All particles

become electrically charged in solution; in wine,

they normally carry a negative charge. If the

negative charge of a wine is altered by adding

particles with the opposite charge, particle repulsion

is neutralized. Particles combine to form larger

aggregates that sink to the bottom or float to the

top, i.e., the particles are flocculated or coagulated.

(See Flocculation.)

0040A number of organic and inorganic substances are

available for treating the wine. With the exception of

silica sol, the inorganic fining agents serve primarily

to prevent turbidity and to eliminate nonbacterial

disorders. In other words, their main function is to

stabilize the wine. Today, fining is usually carried out

with gelatine and silica sol, and bentonite is used for

stabilization. Special effects can also be achieved with

casein, isinglass, albumen, and tannin.

Sulfiting

0041Prior to filtration, the wines must be adjusted to a

certain sulfurous acid concentration. Sulfur dioxide

(SO

) dissolves in wine to form an equilibrium

mixture [1]:

Ð HSO



Ð SO

2

ð1Þ

and it has been added to wines since time immemorial

to improve the storage characteristics. It inhibits the

growth of, or even kills, certain bacteria, and also

prevents browning and oxidation reactions; certain

substances are reduced, and taste is improved. This

versatility makes sulfite indispensable in the cellar.

(See Preservation of Food.)

0042One of the essential tasks of the ‘free’ SO

is to

bond the small quantities of organoleptically perceiv-

able acetaldehyde, thereby neutralizing its sensory

characteristics. If free acetaldehyde is present in the

wine, the wine creates a sensory impression that is

6200 WINES/Production of Table Wines

labelled rancid, ‘maderized’ and oxidized or ‘sherry

taste,’ and avoidance of this defect is vital in white

wines.

0043 Sulfurous acid has no significance as a preservative

in wine as the permissible maximum contents are

too low.

Stabilization

0044 Although fining and filtration are normally sufficient

to obtain a limpid and clear wine, they can become

turbid again after this treatment or can exhibit

deposits. Colloidal proteins can alter and become

insoluble. Wines containing thermolabile proteins

are most frequently stabilized by treatment with min-

erals containing aluminum silicate. Bentonites are

most suitable for this purpose. It is also possible that

heavy-metal ions will cause discoloration or turbidity

because they may either form insoluble colored

compounds with the wine components or become

insoluble and precipitate out. These phenomena are

primarily caused by iron and copper ions.

0045 In 1922, success was achieved in bonding the iron

and precipitating it to a large extent by adding a

precisely determined amount of potassium ferrocya-

nide (potassium hexacyanoferrate (II)). Subsequently,

it was found that a series of other metal ions, such as

those of copper, zinc, manganese, nickel, and silver,

and the extremely toxic metal ions of lead and

cadmium, could be precipitated out as ferrocyanide

complexes. (See Heavy Metal Toxicology.)

0046 After fining of the wines to protect them against

changes, a further stabilization is normally required

to inhibit crystalline precipitation. This is aimed

chiefly at separating out potassium bitartrate together

with calcium tartrate, i.e., the so-called cream of

tartar. To prevent tartrate precipitation, it is usual to

cool the wine down to a temperature of between þ4

and 0



C for a period of 4–10 days. After fining and

stabilization, the wines must be completely clarified

prior to bottling.

0047 Whereas centrifugation is only suitable for separat-

ing out relatively coarse trub particles, filters can

remove even particles down to the molecular range

from the wine.

0048 Three different types of filter are applied to wine

filtration: the so-called precoat filter, in which the

porous mass constantly reforms during filtration;

the sheet filter, in which the porous mass is prepared

beforehand and placed in the filter; and the mem-

brane filter, which has a defined pore size. Purely

mechanical clarification has a negligible effect on

the chemical composition of white wines. However,

the sensory properties are improved substantially.

Bottling

0049After development of the wine in the cellar, the wine

must be ‘bottle ripe’, i.e., it must be physically, chem-

ically, and biologically stable. White wines in particu-

lar should be optically clear as well as tasting fresh

and elegant to meet the requirements of today’s con-

sumer. In the case of red wines, long aging in wooden

casks is desirable (Bordeaux wines). (See Barrels:

Wines, Spirits, and other Beverages.)

0050A bottling line consists of machines and equipment

for cleaning the bottles, bottling, corking, capsuling,

labelling, packing (in plastic cases or boxes) and pal-

leting (15, 15). The most important feature of bot-

tling of wine is the microbiological stabilization of the

wine to ensure that the bottled wines do not become

turbid due to the activity of microorganisms. In prac-

tice, this means cold-sterile or hot-sterile bottling of

the wine.

0051Central to cold-sterile bottling is bacterial clarifica-

tion of the wine by filtration with fine-pore filter

sheets (sterilizing filters or germ-proof filters) or

membranes (Figure 1 (14), Figure 2 (15) ). The diffi-

culties associated with cold-sterile bottling can be

overcome by heating the wine. For an alcohol content

of c. 10% by volume, a bottling temperature of 55



is adequate.

Classification

0052The composition and nature of a wine depend

on the grape variety, the site and soil of the vineyard,

the climate and growth conditions of the vine, and the

state of the grapes. They are also greatly influenced by

the must treatment, the yeast, and the treatment of

the wine in the development stage. The quality of the

wine generally depends on the amount of volatile

compounds, such as ethanol and aromatic sub-

stances, and the content of nonvolatile compounds,

which are classified under the heading ‘extract.’

0053Wines can be classified, to a certain extent, by the

analytical determination of individual components.

In particular, it can be established whether the legally

defined maximum and minimum limits have been

adhered to. Adulteration by addition of nonpermis-

sible substances such as acids can be detected. (See

Adulteration of Foods: History and Occurrence.)

0054However, it is difficult to make an objective assess-

ment of the quality of the wine with the aid of chem-

ical analysis. Table 1 gives an overview of a number

of important wine components.

0055Classification of a wine, therefore, necessitates a

sensory evaluation as well as the results of chemical

analysis. The current consensus is that analytical and

sensory tests are equally important and complement

WINES/Production of Table Wines 6201

one another. In sensory evaluation of the quality of

wine, color, odor, and flavor are evaluated.

Physiology and Toxicology

0056 The value of a wine lies in the combination of sensory

impressions such as odor and taste and the specific

effect of the alcohol, which together make drinking in

moderation a pleasurable experience. The predomin-

ant component is the ethanol, which enters the blood-

stream relatively rapidly as it is easily absorbed by the

mucous membranes in the mouth and stomach, but

mainly in the small intestine.( See Sensory Evaluation:

Sensory Characteristics of Human Foods.)

0057As is the case with all other aliphatic alcohols,

ethanol affects the central nervous system, causing

anesthesia and intoxication. It is degraded chiefly in

the liver, where, in the first stage, acetaldehyde is

formed by alcohol dehydrogenase, this is converted

to acetic acid in the second stage by aldehyde hydro-

genase and is metabolized to carbon dioxide and

water in the citrate cycle. (See Alcohol: Metabolism,

Beneficial Effects, and Toxicology.)

0058Sulfur dioxide is the only component with any

toxicological significance that is used in the develop-

ment of wine. Approximately 95% of the sulfite in

the wine is absorbed by the body. It is oxidized to

sulfate by the sulfitoxydase present to some degree in

all body tissue. The latter is essential for the human

body and is needed for the degradation of sulfur-

bearing amino acids. The oxidation of sulfite to sul-

fate takes place with amazing speed. To date, it has

not been possible to detect sulfurous acid in body

fluids. The sulfate is discharged almost completely

via the urine within 24 h, as has been demonstrated

in tests using radioactively labeled sulfur. For this

reason, there is, at present, no evidence that sulfurous

acid poses a threat to health if it is added to wines in

the legally permitted concentrations.

See also: Acids: Natural Acids and Acidulants; Colorants

(Colourants): Properties and Determination of Natural

Pigments; Filtration of Liquids; Flocculation; Heavy

Metal Toxicology; Port: The Product and its

Manufacture; Ripening of Fruit; Sensory Evaluation:

Aroma; Taste; Sherry: The Product and its Manufacture;

Tannins and Polyphenols; Vermouth; Wines:

Production of Sparkling Wines; Yeasts

Further Reading

Amerine MA, Berg HW and Kunkee RE (eds) (1982) The

Technology of Wine Making. Westport, CT: AVI.

Bergner KG and Lemperle E (2001) Weinkompendium, 3rd

edn. Stuttgart, Leipzig: Verlag Hirzel.

Farkas J (1988) Technology and Biochemistry of Wine.

Montreux: Gordon and Breach.

Gollmick F, Bocker H and Gru

nzel H (eds) (1991) Das

Weinbuch. Leipzig: Fachbuchverlag.

Gussek KD and Bocker H (1990) Der Wein (Lexikon).

Leipzig: Bibliographisches Institut.

Jackson RS (1994) Wine Science: Principles and Applica-

tions. London: Academic Press.

Jakob L (1995) Lexikon der O

nologie, 3rd edn. Neustadt:

Verlag und Druckerei Meininger GmbH.

Jakob L (1997) Der Wein, 10th edn. Stuttgart: Verlag E.

Ulmer.

Lea AGH and Piggott JR (eds) (1995) Fermented Beverage

Production. Glasgow: Blackie.

tbl0001 Table 1 Important components (g l

1

) of wines

Alcohols

Ethanol

Table wines 50.0–110.0

Dessert wines 104.0–176.0

Methanol

White wines 0.02–0.1

Red wines 0.09–0.75

Glycerol 3.5–25.0

Butylene glycol c. 0.6

Isobutylene glycol c. 0.12

Sorbitol c. 0.02

Acids

Total

White wines 4.0–9.0

Red wines 4.0–6.0

Malic 0.0–6.0

Tartaric 0.5–4.0

Malic 0.8–3.3

Succinic 0.5–1.3

Citric 0.0–0.3

V olatile acids

Acetic 0.15–1.2

Carbonic 0.0–1.5

Sulfurous acid free 0.002–0.05

Sulfurous acid bound 0.08–0.40

Sugars

Fermentable 0.0–150.0

Nonfermentable 1.0–2.5

Arabinose 0.5–0.8

Tannins

White wines 0.05–0.4

Red wines 1.0–2.5

N itrogen compoun ds

Total 0.1–0.9

Protein nitrogen 0.03–0.04

Proline 0.14

Glutamic acid 0.21

Histamine 0.0–0.22

Mineral matter (ash) 1.5–3.0

Potassium 0.5–2.5

Magnesium 0.07–0.24

Calcium 0.1–0.2

Sulfate 0.15–1.0

Nitrate 0.015

From Gollmick F, Bocker Hand Gru

nzel H (eds) (1991) Das Weinbuch.

Leipzig: Fachbuchverlag, with permission.

6202 WINES/Production of Table Wines

Ribe

reau-Gayon J, Peynaud E and Sudraud P (eds) (1972–

1977) Traite

d’Oenologie, Science et Techniques du Vin.

I, Analyse et Contro

le des Vins (1972); II, Composition,

Transformation et Traitements des Vins (1966); III,

Vinifications, Transformation du Vin (1976); IV, Clari-

fication et Stabilisation. Materiels et Installations

(1977). Paris: Dunod.

Troost G (1988) Technologie des Weines, 6th edn. Stuttgart:

Eugen Ulmer.

rdig G and Woller R (eds) (1989) Chemie des Weines.

Stuttgart: Eugen Ulmer.

Production of Sparkling Wines

S Buxaderas and E Lo

pez-Tamames, University of

Barcelona, Barcelona, Spain

Background

0001 Carbonic acid gas and the capacity to form

bubbles are the characteristics that differentiate

sparkling wines from other types of wines on the

market. These wines are consumed for the most part

in cocktails, aperitifs, and special occasions (wed-

dings, baptisms, birthdays, etc.), probably because

they are considered elegant wines. They are required

to have a clear sparkle, a perfect tonality (especially

white sparkling wines, the most popular kind), a

harmonious bouquet, and a refined and attractive

presence. These qualities can be achieved only with

raw materials of the best quality and a meticulous

elaboration, which explains their tendency to be on

the expensive side.

0002 Although sparkling wines are mostly consumed in

social events, in the producing countries, different

types of sparkling wines are prepared for other occa-

sions. The brut type (dry or almost dry) may be drunk

as a table wine, as an aperitif, or with fish, and also

along with cheese. Others are dessert wines, such

as the sparkling Asti, or appetizer wines, such as

Prosecco.

0003 Sparkling wines are gassy beverages in which the

carbon dioxide is found in a state of oversaturation

(generally, 4–6 bar at 20



C). When the wine is

poured into a glass, CO

is rapidly released as a result

of the difference in pressure between the hermetically

sealed bottle and atmospheric pressure. The efferves-

cent CO

bubbles reach the wine surface forming,

during the first seconds, a great volume of foam,

which seconds later, is reduced to a foam collar. The

endogenous or exogenous origin of the CO

allows

these wines to be classified into two large groups:

natural sparkling wines (those produced by the

Champenoise, Charmat method (or similar methods),

or the ‘pearl’ wines, which have a natural ‘sparkle’)

(Figure 1), and those carbonated artificially (aerated

sparkling wines).

0004In the first case, a dry wine to which sugar (sac-

charose or concentrated must) has been added is

refermented or subjected to a second alcoholic fer-

mentation either in a sealed bottled (as in the Cham-

penoise method and other similar methods) or in

pressurized tanks (as in the Charmat method). Other

sparkling wines are processed by refermentation of a

must partially fermented using their own sugar. In

these products, the pressure of carbon dioxide forms

effervescence, but it does not reach the values neces-

sary to form foam. These wines can also be included

within this group, since the CO

origin is endogen-

ous. In the European Union (EEC regulation of the

1493/99), the denomination of sparkling wine is only

applied to those wines that, when uncorked and

poured into the glass, are able to form foam. This

would explain why pearl wines, which do not reach

the 3.5 bar of CO

pressure (measured at 20



C), are

not considered sparkling wines, but semisparkling

wines. In the second case, gassy carbon dioxide of

exogenous origin is added directly to a wine (aerated

wines), thus creating the more modest types of

sparkling wine.

Champenoise Method

0005The first historical information concerning the prep-

aration of a sparkling wine dates back to the seven-

teenth century in France. At the end of that century,

the abbot Dom Perignon (1638–1715) tried to

rationalize the natural tendency of Champagne

wines to sparkle lightly in the bottle. The Champen-

oise method, probably because of its geographical

proximity, expanded to the north of Spain (Catalo-

nia) around 1842 (Montferrant Cellar) and 1878

(Codorniu Cellar).

0006At present, within the European Union (EU), the

Champagne region in France (located in the Epernay

and Rheims area) is the only region that can use the

denominations of the Champenoise method and

Champagne for the production of sparkling wines.

Other natural sparkling wines produced in other

regions of France are known as vins mousseux.In

Italy and Spain, the Champenoise method is desig-

nated classic (metodo classico, Talento wines, and

Spumanti Metodo Classico) and traditional (me

todo

tradicional, Cava wines), respectively. These spark-

ling wines are considered to be of premium category

WINES/Production of Sparkling Wines 6203

when their quality is guaranteed by a Certified Brand

of Origin (CBO) (quality wines called p.s.r., ‘pro-

duced in specific regions,’ according to the EU’s ter-

minology) (EEC regulations 823/87 and 2043/89).

The regulations that entitle natural sparklers to re-

ceive a CBO are strict and establish the authorized

grape varieties and their place of cultivation, the

maximum yield per vineyard (kilograms of grapes

per hectare), the viticulture, and the winemaking pro-

cesses, sometimes to the point of specifying details

such as the type of material to be used in ageing

wine and the period of this ageing. In the USA, the

denomination of Champagne for sparkling wines

produced according to the method champenoise (or

called ‘fermented in the bottle’) can appear on the

label on the condition that the geographic place of

its processing is mentioned (and thus labeled as

Californian Champagne, New York Champagne, and

so on).

0007In the Champenoise method, as well as in the

classic and traditional methods, there are two pro-

duction stages: preparation of the base wine (pressing

of the grapes, clarification and fermentation of the

must, and clarification and stabilizing of the wine)

Aerated wine

Semi-sparkling wines

Charmat method

Champenoise or

traditional method

Transfert method

White wine vinification

Base wine

(grape sugars, sometimes

addition of concentrated must)

Moscato d9Asti

Frizzante

Vinhos verdes

Refermentation

Prosecco

Asti espumanti DOCG

Sekt QbA

Champagne AOC

Cava DO

Talento DOG

fig0001 Figure 1 Process for making sparkling wines.

6204 WINES/Production of Sparkling Wines

and the sparkle stage (bottling and ‘tirage’ process,

second fermentation, ageing of the wine on its lees,

elimination of yeast or riddling, disgorging and add-

ition of the ‘expedition liqueur’). The differences

detected among the Champagne sparkling wines, the

Spumanti Metodo Classico, and the Cava are due to

the different grape varieties used, the viticultural eco-

system of the geographic area, and the enological

practices applied (type of pressing, blending (cou-

page) of the wines that will make up the base wine,

yeast strains used for the first and second fermenta-

tion, period of contact with the yeast during

maturation, etc.).

0008 The French grape varieties Pinot noir, Pinot meu-

nier, and Chardonnay are the main varieties used all

over the world to produce natural sparkling wines (in

Italy, England, USA, Australia, New Zealand, etc.).

Sometimes, these wines are blended with wines from

other varieties that may or may not be native to the

area. In Italy, Pinot blanc is also used. In England,

these varieties are blended with hybrid varieties (e.g.,

Bacchus, a cross between a Silvaner and Riesling

hybrid with a Mu

ller-Thurgau grape, and Kerner, a

cross between Riesling and Schiave grossa grapes)

and other English varieties (e.g., Schonburger). Span-

ish Cava is probably one of the few exceptions. The

main grapes used are native varieties (Macabeo, Xar-

ello, and Parellada) as a way of fostering Cava’s dis-

tinctive sensory characteristics. Only the foreign

variety of Chardonnay is allowed for white sparkling

wines and the Pinot noir variety for Cava rose

Base Wine Preparation

0009 This preparation involves off skin fermentation, but

with certain peculiarities. Grapes are picked in 20–

25-kg lugs (in Italy and Spain) or 35-kg lugs (in

France) so that the grapes reach the winery un-

crushed. It is better to avoid the release of phenolic

compounds from the broken skins and the reactions

of enzymatic oxidation. That is also why grapes

are pressed gently with mechanical or pneumatic

horizontal or lateral presses, which have replaced

the old vertical basket presses. The free-running

juice produced during the loading of the press and

the grape juice, which is extracted with very gentle

pressure, are used to produce the highest-quality

natural sparkling wines, whereas the must obtained

by increasing the pressure is used for lower-quality

sparkling wines or other wines such as table

wines The regulation of the Champagne Certified

Brand of Origin (A.O.C., ‘Appellation d’Origine

Contro

e)’ and that of Cava (D.O., Denominacio

de Origen) requires a 66.6% must yield, which is

slightly higher (max. 70%) for the Talento (D.O.C.,

‘Denominazione di origine controllata’). Approxi-

mately 2.7 l are obtained from 4 kg of grapes, consti-

tuting the free-running juice and the juice of the first

press fraction.

0010The must is treated with sulfur dioxide to block

polyphenol oxidase and prevent uncontrolled fermen-

tation. Before alcoholic fermentation occurs, the must

is racked by physical methods (sedimentation for

12–24 h, then filtration or centrifuging) and its acid

and sugar levels corrected. The cold climate of the

Champagne region and Germany is responsible for

the high acid but low sugar levels, thus necessitating

chaptalization (addition of sugars). Musts obtained in

the Mediterranean climates of Italy, Greece, and

Spain have sufficient quantities of sugar to ensure

a minimum alcohol content of 9–9.5% of base

wines, but it is often necessary to add tartaric and/or

citric acid. Alcoholic fermentation is carried out at

16–20



C so as to minimize the loss of aroma. Tem-

perature control is facilitated when fermentation

occurs in stainless steel tanks, which incorporate a

refrigerating system (double jacket). Since fermenta-

tion may take several days to finalize, wine is devatted

before fermentation is completed to prevent the ap-

pearance of mercaptan compounds resulting from

prolonged contact with the lees. Dry wine, with a

residual sugar content usually no higher than

1.5 g l

1

, is left to settle for several months (cloudy

wines). During this time, it is clarified by sedimenta-

tion, and if this is not adequate, fining agents are

employed (bentonite, gelatine, caseinates, etc.). Mal-

olactic fermentation is favored only when the acidity

is excessive (15 g of malic acid per liter). Malolactic

fermentation should not occur in the bottle, since this

would increase the CO

pressure, and colonies of

lactic bacteria would form viscous lees attached to

the inside of the bottle. Tartaric stabilizing involves

precipitation of tartrate salts. Tartaric acid and its

salts become less soluble in hydroalcoholic solution

when sparkling wine is at a low temperature. To

prevent tartaric crystals forming the tank temperature

is reduced below 0



C(4



C). Finally, a sterilizing

filtration is carried out (base wine). Generally, the

base wine is not a monovarietal wine. The blending,

or coupage, among wines of different characteristics

can be done in the tank for tartaric stabilization or

before filtration to yield a base wine with more

rounded sensory properties. It is permissible for

some natural sparkling wine labels to indicate

the proportion of monovarietal wines used in the

preparation of the base wine (as in France, Italy,

Germany, USA, and South Africa), but in other coun-

tries, such as Spain, Greece, and Argentina, the wine

varieties may be mentioned, but not the proportions

of the blend.

WINES/Production of Sparkling Wines 6205

Fermentation and Aging in Bottle

0011 The settling of the sparkle, or prise de mousse phase,

starts with the ‘tirage’ process, when the wine is

bottled, and the sugar and yeast solution are added.

The ‘tirage liqueur’ is added to the base wine (55 ml

of wine-liqueur mix per liter). The composition of this

liqueur is: 1–2 million cells of yeast per milliliter,

500 g of saccharose per liter and 0.1–0.2 g of ben-

tonite per liter to agglutinate the lees during riddling,

and/or ammonium phosphate (50 ml hl

1

) and others

compounds to stimulate yeast growth. The bottle

glass is usually thick to withstand the CO

pressure

generated by the second fermentation (5–6 bar at



C before opening). The bottles are hermetically

sealed with a cup-shaped plastic insert, known as a

bidule, and a metal crown cap, and are stacked hori-

zontally in bins or along cellar walls, at a temperature

of 12–14



C. The settling of the sparkle phase varies

in duration; a minimum of 9 months for Cava and

15 months for Champagne and Spumanti Metodo

Classico. This length of time is sufficient for the

second alcoholic fermentation to take place and for

the exchange of compounds between the yeasts and

the wine. However, the ageing period for natural

sparkling wines tends to be much longer. Yeast au-

tolysis is believed to occur 9 months after the tirage.

This enzymatic process implies the release of com-

pounds from the cell walls followed by a progressive

dissolution of the cytoplasmic compounds in wine.

Between the 12th and 18th month, marked changes

are detected in the wine composition (the content of

polysaccharides, peptides, and free amino acids rises,

and that of proteins falls). Undoubtedly, the special

ageing of natural sparkling wines depends on this

contact between the wine and the less of the second

fermentation, but the reducing atmosphere created by

the CO

also plays a part. The complex reactions that

take place during the settling of the sparkling wine are

still under study, but they are known to give rise to

each wine’s special and characteristic bouquet

(matured aromas and flavors that supply the fruity,

nutty, yeasty, and toasty notes). The most frequent

ageing period is 2–3 years, although in some cases, it

may be up to 6 years, but sparkling wines tend to lose

their freshness if left to age excessively. When the

wine has reached the desired ageing, the dead yeast

cells have to be eliminated through the riddling

(remuage) process. The sediment that has accumu-

lated in the bottle on the side on which it has been

lying is directed to the mouth of the bottle and is

gathered in the bidule of the inverted bottle. In

manual riddling, the bottles are placed in classical

racks, called pupitre, at an angle of 25–30



from the

ground. Bottles are progressively given an 1/8 twist,

and their inclination is also increased, so that the

sediments slide to the mouth of the bottle. At the end

of the riddling operation, the bottle is neck down and

the sediment is in the bidule, ready for disgorging.

Classical hand riddling requires many specialized

workers and lasts for 1, 2, or more months. This is

why most wineries have replaced the racks with 500-

bottle bins, which rest on an inverted octagonal pyra-

mid. Each change of the octagonal face on which the

bin is resting represents the 1/8 spin of the rack. At the

same time, bascule guides increase the inclination of

the bin until it is vertical. The most sophisticated

riddling system has replaced the mechanical control

of the bin movements on the octagonal base with

automatic riddling machines. These modern systems

take only 2–4 weeks to do all the riddling. There are

also automatic racks (Pupi-matic) that continually

shake and tilt 240 bottles. The process only lasts 10

days but requires more workhands to load and

unload the rack than the bin system, whose unloading

into the disgorging machine is mechanized. The

bottles sitting in the neck-down position facilitate

the disgorging process. The mouth of the bottles is

plunged into a freezing solution of ethylene glycol

(45%). When the crown cap is removed, the ice plug

with the frozen sediment shoots out of the bottle due

to the CO

pressure. Pressure loss is approximately

1 bar, and wine loss is 10–15 ml. The volume lost is

restored by adding the filling solution or ‘expedition

liqueur’. This is made up by wine recovered from the

disgorging, or an aged wine, to which sugar and

sometimes liquor (e.g., Armagnac, brandy, or rum)

or a fortified wine is generally added. Sparkling

natural wines in the EU receive different appellations,

depending on the amount of sugar added to the ex-

pedition liqueur: Brut nature < 3 g l

1

(only residual

sugars), extra brut 0–6gl

1

, brut < 15 g l

1

, extra dry

12–20 g l

1

, dry 17–35 g l

1

, medium dry 33–50 g l

1

and sweet > 50 g l

1

. Sweetness tends to disguise some

defects in the wine. Therefore, natural sparkling

wines of premium quality are the brut nature and

extra brut wines, which contain only the residual

sugar of the second fermentation or have been

sweetened only very slightly. For these natural spark-

ling wines, the raw material and the production pro-

cess must be impeccable. The bottle used in the

settling of the sparkle is the same bottle that reaches

the consumer, corked, foiled, and duly labeled.

The Charmat or Granvas Method (or Bulk

Method)

0012The basic difference in this method compared with

the Champenoise method (fermentation in the bottle)

6206 WINES/Production of Sparkling Wines

is that the second fermentation is carried out in a

Charmat tank (a sealed tank that traps the carbon

dioxide gas produced during the second fermenta-

tion). This is the main method used in the USA,

Australia, and New Zealand) (Table 1). The period

of time during which the wine is in contact with the

lees of the fermentation distinguishes the short

Charmat from the long Charmat. Young and fruity

wines preferably should not lose these sensorial char-

acteristics by ageing in contact with the yeasts. The

organoleptic result of ageing on the lees reduces their

value. This is the case with the Italian Asti and

Prosecco. The production method most suitable for

these is the short Charmat.

Short Charmat Method

0013The base wine (monovarietal or coupage) ferments in

a Charmat tank to which the ‘tirage liqueur’ (sugar,

nutrients, and yeast) has been added. This liqueur has

a similar saccharose concentration to that used in the

Champenoise method, but less volume is added

(44 ml instead of 55 ml of wine-liqueur mix per

liter). Then, 10% of yeast-enriched wine is added to

the sweetened base wine. The ideal temperature for

fermentation is 12–13



C. When the desired CO

pressure has been reached (approximately 4 bar),

the temperature of the Charmat tank is reduced to



C to arrest the fermentation (with 10% of residual

sugars). The low temperature causes the suspended

yeast to sink to the bottom. The next step is to trans-

fer under pressure the partially decanted wine, al-

ready bubbly, to the Charmat tank where it will be

cold stabilized. When the wine is transferred from one

Charmat tank to another, it is filtered or centrifuged

to separate it from the lees, thus ensuring minimal

contact between the wine and the lees to prevent the

yeast from absorbing bouquet notes. Filtration by

counter-pressure uses a gas (usually carbon dioxide)

to compensate the empty volume of the Charmat tank

while it is being emptied of the wine. The gas that is

introduced will be at least 1 bar higher than the

pressure of the sparkling wine to ensure that it

remains invariable. This is also why the gas intro-

duced into the second Charmat tank, which will re-

ceive the sparkling wine through the filter or hermetic

centrifuge, remains at the same pressure as that of the

sparkling wine. The gas used most often is nitrogen,

rather than compressed air or carbon dioxide. Com-

pressed air is not favored because of the negative

influence of oxygen on wine. In some countries,

such as France, Italy, or Spain, the use of industrial

carbon dioxide is forbidden in cellars that produce

natural sparkling wines, and can be employed only by

companies that produce artificially gasified sparkling

wines. However, it is possible to use the carbon diox-

ide that is recovered from the alcoholic fermentation

as a compensation gas. If necessary, tartaric cold-

stabilizing (4



C) is carried out when it has not

previously been applied to the base wine. The wine

is then refrigerated at 0



C to prevent liquid loss,

especially between the bottling and corking process.

0014There are several sparkling wines of excellent qual-

ity that deserve special attention, such as the Moscato

d’Asti (a semisparkling wine, according to the EU’s

denomination) and the Asti spumate (Asti DOGC:

denominazione di origine controllata e garantita)

tbl0001 Table 1 1998 world production

of sparkling wine

Origin Type of

sparkling wine

Quantity

of sparkling

wine bottled

produced

(10 0 0)

Percentage

of the

sparkling

wine type

Argentinean Others 23.148 100

Australian Method traditional 17.700 34.3

Others 33.900 65.7

Austrian Sekt 18.024 86.6

Frizzante 2.832 13.5

Others 84 0.1

Brazilian Method traditional 1.302 6.4

Others 19.050 93.6

Canadian Method traditional 1.061 13.4

Others 6.859 86.6

Chilean Others 10.104 100

Chinese Others 15.342 100

French Champagne 272.160 53.2

Method traditional 22.232 4.3

Others 217.056 42.4

German Sekt 257.904 59.1

Others 178.320 40.9

Greek Others 888 100

Italian Method traditional 16.925 9

Asti 49.968 26.9

Prosecco 26.472 14.3

Others 92.196 49.7

Japanese Others 1.650 100

Mexican Method traditional 324 45.0

Others 396 55.0

New Zealand Method traditional 4.464 41.4

Others 6.312 58.6

Portuguese Others 12.924 100

Russian Others 2652 100

South African Method traditional 663 6.2

Others 10.116 93.8

Spain Cava 190.508 81.4

Others 43.632 18.6

Swiss Others 264 100

Turkish Others 204 100

Ukrainian Sekt 90 100

Uruguayan Others 408 100

USA Method traditional 40.440 33.3

Others 80.856 66.7

Venezuelan Others 666 100

Data provided by Freixenet, S.A. cellar.

WINES/Production of Sparkling Wines 6207

(Table 2). The Moscato d’Asti is thought to be origin-

ally from Piamonte in Italy, and as ancient as Cham-

pagne. There are dessert wines produced from muscat

grapes (Moscato bianco) and with a low alcohol con-

tent (4.5–5.5%), which differ from the sparkling

wines previously described in that the base wine is a

must wine whose second fermentation is carried out

using sugars from the grapes of origin. In the past, the

artisan production of the Moscato d’Asti meant that

alcoholic fermentation had to be arrested when the

desired alcohol content, CO

pressure, and quantity

of residual sugars had been reached. Successive filtra-

tions and the elimination of nitrogenated compounds

gradually diminished the fermentation process until

the critical point was reached. This point was deter-

mined by the percentage of nitrogen present and the

quantity of live cells that made the wine incapable of

fermenting when exposed to low-temperature, alco-

holic, and reducing (CO

) conditions. At present, the

procedure for producing Moscato d’Asti is essentially

the same, but modern techniques are available to

facilitate the process (temperature of 3



C, steriliz-

ing microfiltration, and the use of selected yeasts).

The filtered must is left to lie at 0



C for 12–15

months. During this time, as soon as incipient fermen-

tation is detected, the must is filtered and refrigerated

again to eliminate and deactivate any yeasts, and it

reaches a maximum alcohol content of 1%. Once the

ageing period has passed, selected yeast strains are

added, and the must is left to ferment at a controlled

temperature of 18–20



C. When an alcohol content of

4.5–5% is reached, and approximately 80 g of residual

sugars per liter are left over, fermentation is stopped by

refrigeration at 3



C, followed by microfiltration

and bottling. In some cellars, the product may be

pasteurized to ensure that a second fermentation

does not reoccur. The difference between the Moscato

d’Asti and the Asti spumante is the alcohol content

and CO

pressure in the bottled product. Asti spu-

mante ferments aged must wine with 1% alcohol in a

Charmat tank until an alcohol content of 7.5–9% is

reached. As for the pressure, once fermentation has

started, CO

is released, but when the product ap-

proaches the 5% alcohol content, the Charmat tank

valve is closed. The pressure in the tank will reach 6–7

bar at 20



C so as to ensure a pressure of 3.5 bar once

the product is bottled.

Long Charmat Method

0015This method is used to produce sparkling wines with

organoleptic characteristics that are closer to those

achieved by the Champenoise method, especially

wines of the Pinot and Chardonnay varieties. This is

because the period during which the wine remains in

the Charmat tank of fermentation is prolonged for

several months (minimum 6 months). Wine ageing in

contact with the lees gives rise to the development of

aromatic compounds typical of this special ageing

process. Another difference with respect to the short

Charmat is that the sugar added for the second fer-

mentation should be the necessary one to obtain a dry

sparkling wine with a pressure of around 6 bar. Once

the 6-bar pressure (measured at 20



C) is reached, the

wine is kept in contact with its lees for 9 or more

months at room temperature and with intermittent

riddling. The riddling is delayed 2 or 3 weeks before

the end of the ageing period, and the wine is then

decanted. The decanted wine is centrifuged, and at

the exit, a dosage pump injects expedition liqueur

suitable for the type of sparkling wine desired.

Then, the centrifuged wine is filtered into the Char-

mat refrigeration tank. The refrigeration temperature

tbl0002 Table 2 Enological characteristics of some natural sparkling wines

Parameters Cava Champagne Moscato d’Asti

Asti Spumante Talento

Etanol (% v/v) 10.8–12.8 > 11 4.5–6.5 7–9.5 > 11.5

Total acidity (g l

1

) > 5.5 > 5.5 > 5 > 5 > 5.5

Residual sugar (g l

1

) < 3 < 3 > 50 > 50 < 3

Extracto seco (g l

1

) 13–22 > 16 > 15 > 17 > 16

Pressure CO

(bar) > 3.5 > 3.5 < 1.7 > 3 > 3.5

Aroma/notes Butter Fruity Ripe fruits Muscatel Fruity

Honeysuckle Floral Muscatel Cooked apple

Honey Woody Terpenes: linalool,

nerol, geraniol

Furanic oxydes

Breadcrumbs Spicy a-terpineol

Nuts Bread Ho-trienol

Color Pale yellow Golden yellow Yellow, made of straw Pale golden, made of straw Yellow with

golden shadeStraw-colored

Green tint

A semisparkling wine.

6208 WINES/Production of Sparkling Wines