, From Italy with Wine: From Italy with Wine - Wine production process

Wednesday, July 12, 2017

From Italy with Wine - Wine production process

In this post we want to introduce the wine production process (Vinification), in order to give to all readers the possibility to understand which is the amount of needed knowledge around vines, wine and must. We hope you can enjoy with this article/post.

In the past, wine was only considered a food or supper to be taken to sustain a tiring day.
In the last century in Italy viticulture had a remarkable development by identifying and selecting vines according to climatic and morphological characteristics.
In Italy today, wine is produced in all regions, while in France, for example, there is no possibility above the Champagne region: there is therefore a world-wide geographical frontier that can affect production.

To understand the origin of wine, it is necessary to know the characteristics of the plant from which it originates: the vine.
The vine (from the Latin "vine", derived from the Indo-European viere = curving, braiding) is a climbing shrub, spread in vast areas of our planet between the 20 ° and 50 ° degrees North latitude and 20 ° and 40 ° South latitude It is a very resistant plant, able to withstand up to 15 ° C below zero in winter, but preferring temperatures between 8 ° and 13 ° C for sprouting, between 16 and 20 ° C for the Flowering and between 18 ° C and 23 ° C for ripening.
It prefers limestone, preferably well drained, and good sun exposure. It is tempting atmospheric adversities especially hail and frost in the flowering period as they destroy gems and flowers preventing the formation of fruits and sometimes also damaging the crop of the next.
Humidity in the maturation phase of the grain favors the emergence of diseases such as rot and gray mold or botrytes that cause the rapid alteration of the wine. It is tempting some plant parasites such as Oidium and Peronospera that are fought with sulfur-based (for Oidium) and copper (for Peronospera) preventive treatments. Among the animal parasites the most feared is the Fillossera.
The following map indicates the diffusion of vine in the world:

After the 1940s and 1950s, Italian people went to a different consumption, more following the tastes. A school for the combination of food and wine was created in order to make also sophisticated culinary preparations. Over the last twenty years, the quality of wine became more important of the quantity, given the decline in pro capita consumption.

The factors that contribute to the production of a wine are the following:

- ENVIRONMENTAL EVENTS (climate, etc.)

For example, in Trentino Alto Adige, the vines are broader so that they can better capture the sun's rays, on the contrary in the South the vineyards are tree-like.

Example of vines in Trentino Alto Adige

Example of vines in Sicily

The peel is responsible for the coloring of the wine when it comes into contact with the rest of the must. The tannin of peel and grape juice gives that acid flavor and an astringent feeling.

VINE  BIOLOGICAL CYCLE                                     

The biological cycle of the vine consists of budding, flowering, planting, pickling and maturation.
The budding, that is, the opening of the buds, takes place in March. There are three types of buds: the ready or summer buds that originate only on unproductive branches, dormant or hybrid buds that will open the next year in spring to produce buds with flowers and fruits, latent gems that they remain inactive for several years and only open when needed, for example after a frost, to give unproductive branches.
Flowering, ie flower formation, takes place between the end of April and the beginning of June depending on the latitude. The flowers are hermaphroditic and pollination is anemophilic, that is through the transport of pollen by the wind. 
The development into a fruit is the transformation of flowers into fruits (acini) and usually occurs in July. Only a small part of the flowers (about 15-20%) turns into fruits, the others fall (slicing) or stretch into twigs (spinning), both phenomena are a form of self-regulation of the plant to avoid dispersing their own nutritional availability.
In some particular cases, such as nutritional deficiencies or climatic adversities, there is added a third phenomenon called "acinellatura", which consists in stopping the growth of already formed acins. In the swinging phase, the fruit sizes grow in size and color red or yellow depending on the type of grapes, during this period the grape contains a few sugars and is rich in acids. During the period from picking to harvesting, ripening takes about 40-50 days. During this period, the grape juice increases in volume, continues to color and, above all, is enriched with sugars. In addition, on the skins a white waxy substance known as "pruina" is formed, which protects the grapes from adverse weather conditions and retains the microorganisms carried by the wind which are called yeasts and are responsible for the fermentation.
The first harvest of grapes takes place only three years after planting and is rather poor. Production begins to be satisfactory only after 5 years, the quality of wine progressively improves with the age of the vine, but when the plant reaches 30-50 years production begins to decline until it is inexpensive over the years.

When to harvest? From week to week, oenologists study the grapes of the vine by evaluating the balance between acids and sugars:

As time goes on, acids diminish as sugars grow.

The equilibrium point should be the ideal time to harvest and this is determined by the team (winemaker, agronomist, etc.) following the evolution of the vineyard and berry ripening.
Grape ripening is therefore an extremely conditioning factor for the quality before the must and then the wine:
- If you want to get a rich acid product you have to anticipate harvest (usually white wine);
- However, for a wine rich in sugars it is necessary to delay it (usually red wine).

After cutting it, the bunch is transported to the cellar.
During transport, be careful not to crush it in the baskets because excessive weight may break the grapes and cause an early fermentation (acetic acid) due to the unwanted release of pulp and liquid.
A technique for increasing the presence of substances at the top of the cluster is the cutting of the lower part of the same during the growth phase.

To prevent the substances contained in the rasp (pectin, tannins, cellulose, resins) from giving the product a negative or undesirable effect, prior to the pressing of the grapes, the de-structure is performed, i.e. the separation of the grapes from the central axis supporting them.

After further selection of the grapes (discarded broken or molded ones), pressing is obtained by:

  • A solid part (15-20% skins, 3-6% yields)
  • A liquid part (65-75% minimum)
If the pressing was excessive, the emission of bitter substances would be jeopardized

The must obtained with the pressing has this composition:
- Water 70-85%
- Sugars, glucose, also called "grape sugar", most commonly found in partially immature grapes, fructose, in large proportion in grapes with full maturation. Sugars are generally present in hot areas because they are produced by chlorophylline photosynthesis
Carbon Dioxide + Water = Sugar + Oxygen
The percentage of sugars present in the must will determine the alcoholic strength of wine according to this algorithm:
Sugar content x 0,6 = alcohol content%
(1g of sugar yields 0.6ml of alcohol);

 - Organic acids, tartaric tartaric acid, the most characteristic of grapes, acidic sour acid from sour taste, more present in colder areas, citric acid with a fresh taste but much less present than others. The total "acidity" of a must is determined by the sum of:
       - "Fixed" acids (tartaric, malic, citric, other minor acids)
       - "Volatile" acids (acetic acid, present to a lesser extent).
If the acidity is adequate the wine is lukewarm and fresh, if it is too low it is flat, if it is high it is hard; Total acidity is expressed in grams of tartaric acid, from 4x1000 to 9x1000;
- Polyphenols (tannins and dyes), substances that determine the color and taste of wine; They are present in the skin and the razors and also act as antioxidants (for this reason white wines are more delicate as they contain less). They rank in:

  • Anthocyanins (dyes), which give red wine to young wines;
  • Flavons (dyes), important for the color of white wines;
  • Leukoconuts and catechins (tannins) that, in addition to the color of white wines, have the astringent taste;
Nitrogenous substances, which are fundamental for yeast growth and therefore for fermentation (to inhibit it, i.e. Asti spumante)
- Pectic substances (pectin, gums, mucilage), which increase after maturation and decrease after fermentation; Gums and mucilages may be responsible for abrasion;
- Odorous substances ("terpèni"), are present in peels in very variable percentages in the different grapes;
- Minerals, in their entirety defined as "ash" (iron, calcium, copper, etc.), determine the clarity and sapidity of wine; these are absorbed by the ground or by contact with the equipment;
- Microorganisms, are classified in
  • Yeasts, responsible for alcoholic fermentation; In the case of grapes affected by mildew, select yeasts used to purify a "purity fermentation", which will be absolute if there are no original organisms, relative if they are still present;
  • Bacteria, some of the diseases of wine, others capable of producing "malo-lactic" fermentation (lactic acid)
  • Molds, generally damaging to grapes and its derivatives (in the case of Botrydis Cinerea, on the other hand, it determines the formation of very good aromas and flavors (eg Frascati Cannellino)
- Enzymes, proteins that increase the rate of generally harmful chemical reactions
- Vitamins, microelements

In nature, the vine grows spontaneously climbing on the trees and propagates through the birds that eat the fruits. Grapes are the fruit with a higher sugar content, making it particularly attractive to birds favoring their spread. When it reaches full ripening, the grains break out and the juice comes out. The high degree of juice of juice and the presence of yeasts, naturally contained in the grapes, involves the natural fermentation of alcoholic sugars by spontaneously forming the wine. The acids still present in the mature grapes make acid the juice, whose pH is usually less than 4, which promotes yeast growth and the control or complete elimination of many undesirable microorganisms. Part of this acidity remains in wine and along with alcohol content plays a bactericidal role, eliminating many pathogenic agents for humans, particularly those responsible for food poisoning that may otherwise be contracted by drinking contaminated water.
The wine is therefore a spontaneous product, discovered by some of our ancient progenitors.
In fact, the cultivation of vine and the practice of vinification is contemporary to the birth of peasant civilization, that is to the transition from nomadic to sedentary life that has been one of the first important steps in human history. 

Some examples of red vines:
Pinot Nero
Refosco dal Peduncolo Rosso

Some examples of white vines:
Pinot Bianco
Pinot Grigio

Figure related to actual process vine --> wine:

It is characterized by the absence of contact between must and vinegar (maceration).
The steps are:
  • Grapes separation to remove the logs
  • Pressing of the grapes
  • Grubbing to remove the marc (white wine can then also be produced with red grapes as the peel gives the color)
  • Integrity, decantation, filtration, centrifugation
  • Alcoholic fermentation at a temperature of 18-22 ° C
  • To separate the wine-flower from the lees (dead cells, coagulated substances, precipitated salts)

It is characterized by maceration, that is, the contact of the must with the marc, to migrate the substances contained in the skins and the grapes to the liquid and thus give the product the color and aroma appropriate.
The steps are:
  • Clotting the bunches in a soft way
  • Grapes separation to remove the logs
  • Alcoholic fermentation by making contact with must and grape marc; at a temperature of 25-28° C lasts 5-8 days for young wines, 15-20 days for those suitable for aging
  • Rolling-submerging-replacement fermentation to avoid stratification at the top of the marc
  • To separate the wine-flower from the lees (dead cells, coagulated substances, precipitated salts) and vinegars (peels and grains)
  • Twisting of the marc to obtain a "1st" twisting to be joined by the wine-flower to correct it (the residues of the subsequent twisting are used instead for vinegar and distillates)

A white vinification of red berries is carried out with little pigmentation (i.e. Pinot Grigio) or mixing white grapes and red grapes.
Alternatively, it may be a reduced red wine-making: the slightest maceration time on the marc gives a lesser color.
There are "chiaretti" (the most similar to the red ones) and the "cerasuoli" (closest to the whites).

It is applied to get the "novel", who must have at least 11° alcohol.
The whole bunches are placed inside special 50-70 hectolitre tanks, in which, after producing the vacuum, CO2 is emitted, at 30°C for 5-10 days. Indigenous yeasts migrate from the skin to the flesh in search of oxygen and water, triggering an intracellular fermentation process. At the end of the cycle, vinification is carried out in red with a slight crushing and a further fermentation of 3-4 days.
Marketing can not take place before 6th November, day of deblocage, while the final date for bottling is December 31 of the same year of harvest.

Hot wine making is a continuous system that allows rapid vinification and can be used for molded or immature grapes treated directly or after pressing / squeaking.
The liquid was heated to 90°C and then poured onto the solid part of the marc, to obtain a temperature around 65°C.
Another mode is to heat the whole mass up to 60-70° C for a time varying from half an hour to a few hours. The treatment results in an excellent extraction of the pigments and the inactivation of enzymes, in particular of the oxidase, and hence allows less use of SO2.
The defect of this technique is that the organoleptic characteristics are of standard quality and not of high quality.

Continuous wine-making is to immerse in the bottom of the fresh fermenter and to extract it in the upper part of the wine itself that is formed as the lighter alcohol tends to stratify upward.
Given the introduction of fresh must in an environment where fermentation has already begun, the fermentation time decreases and therefore this process saves time.
From a qualitative point of view, a higher alcohol content is obtained, an early malolactic fermentation, an intense color and a lower percentage of methanol.

Alcoholic fermentation consists of the transformation of the sugars present in the must in ethyl alcohol more carbon dioxide (more heat):
Sugars = Ethyl alcohol + Carbon Dioxide

This task is carried out by yeasts that can exert a rapid, strong or slow and delicate action. For this reason yeasts are also selected and added by expert hands.
The total alcohol content of a wine is the sum of the alcohol (the indicated on the label expressed in volume%, eg 12.5%) and the potential alcohol, which would be obtained if the residual sugars were also fermented ( Sweet wines, eg: +/- 2).

There are ad hoc containers in steel to prevent the ideal temperature being exceeded (18-22 ° C for whites, 25-28 °C for reds).
Care should be taken not to stay in environments where the must is fermented because this process emits CO2 (carbon dioxide), making the environment saturated and therefore deadly to man.
During the first period, the fermentation is said to be tumultuous because the red must for the development of CO2. Subsequently, fermentation begins slowly after the rinsing.
In the case of red wines, the fermentation may last 5-7 days for young and ready-made wines, 15-20 days for wines with very color, aromas and extracts suitable for aging.
Always for the reds there is a third stage, malolactic fermentation.

Malolactic fermentation consists in the conversion of malic acid to lactic acid more carbon dioxide:
Malic acid = lactic acid + carbon dioxide
This process, which begins spontaneously in the spring when the temperature rises, is used to reduce the degree of pungency (typical of malic acid) and to make the wine softer (the bacteria work between
20-25° C and Ph ranges from 3.7 to 4.
It comes in ISO9000 containers or in barriques, features 225 liter barrels that release woody, spicy, vanilla substances to the right extent.
The tannin released by the wood is called gallic or noble. It is a characteristic of red wines and makes them more balanced and lighter in color.

To support any deficiencies in the original must, so-called corrections are made, which can be summarized as follows:
- Increase or decrease of
  • Sugar degree, if maturation was incomplete. Italian legislation prohibits the use of sucrose for which cuts are made with more or less sugar-rich musts. An example is the so-called concentrated and rectified must (MCR) that is obtained by evaporating water and creating a mini-must to be used to supplement other poor musts) or from the muddy drop (rendered unslotted for the action of SO2);
  • Degree of acidity, if the vintage was cold and humid. Use of tartaric acid or citric acid to elevate acidity, salts such as calcium carbonate or cuts with less acid musts to reduce it;

- Specific pressures (more or less energetic)
- Contact with the marc
- Cuts with other musts to modify:
  • color
  • Amount of tannins
  • extracts

There are some must-treats that are made using selected yeasts to compensate for any deficiencies or enhance the characteristics of the must:
  • Clarification, to avoid turbidity
  • Filtration, centrifugation, to obtain greater clarity
  • Pasteurization, to eliminate unwanted microorganisms
The must complex treatment is the use of sulfur dioxide (SO2) which eliminates bacteria, blocks fermentation, blocks oxidation (white), accelerates reddish (red) dissolution, slashes (clarification), produces "Mute must" (ineligible).

There are a lot of other technical things about wine and its production, but for the moment we stop here and in case you are curious, please ask for more infos in the comments here below.

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