In the first years that I started drinking it, I remember finding it extremely difficult to recognize the scents, the fruity notes rather than the spicy ones, or even just to understand the quality of what I was drinking. I tried to memorize the names of the grapes or the terms used by the experts, but I could not understand where I sat as a part of the little big world that is oenology.
Then I took courses, I started studying something and above all, I wanted to understand and learn the process of making wine. It may seem trivial, but it’s not easy at all. There are infinite aspects, steps or details that, even if very small, can totally change the final result.
I remember that before proving a didactic approach, the idea of producing a wine frightened me: I saw too many passages, too many notions and too many facets in it that it seemed impossible to memorize everything. Lateral thinking helped me, a less demanding but gradual approach.
First of all, what is wine? Wine comes from grapes, which through certain processes make must and then go on to fermentation: in this phase the yeasts – already present in the wine or in some cases added – begin to eat the sugars: in this way the gradation is obtained.
This is a more than approximate description, as I said before, wine has infinite passages and variations that take years of study and practice to get to know all its aspects. I am not the most prepared person in this regard, but we can say that I have some basic notions that allow me to choose a good bottle when I go to a restaurant or appreciate one wine over another. This is not enough, but I would say it is a good start.
Not many days ago, chatting with an extremely passionate sommelier friend of mine, I had a few more processes explained in more detail. I tried to report some here, in writing, but I want to specify that this little information is for those who know little or nothing about wine. Although it may seem approximate, I think that as a first approach it may be useful not to go into detail but to know only the main processes.
First of all, the grape has a pulp consisting mainly of water, sugar and acids. During the harvest, or when the time comes when the grapes reach the right level of ripeness, they must be stored without any damage and stored in such a way as to avoid starting the fermentation processes ahead of time.
The grape seeds contain the tannins, acids, minerals essential to give substance to the wine after fermentation. These are so important that, before the harvest, their correct maturation is also checked: the wine could be bitter if they have not reached the right maturation.
Then the must is created, that famous compound that we have surely seen in some films where someone crushes grapes with their feet. The must, with the slushy consistency of a semi-solid liquid, has a percentage of sugar that reaches up to 35% (even more for dried grapes). Sugars are divided equally into fructose and glucose – and both can undergo fermentation.
At this point, in more conventional wines, selected yeasts are often added to ensure that the wine acquires certain olfactory characteristics. In organic wines, on the other hand, selected but neutral yeasts are used, that is, they only help to start the fermentation but do not bring any variation in the aromas. On the other hand, in biodynamic and natural wines (terms that by law cannot be used) fermentation is spontaneous, therefore without the addition of external yeasts.
The vinification (fermentation) takes place in stainless steel containers or directly in wood (a technique widely used by the French, the so-called “Batonage”). This process is made possible thanks to microorganisms (saccharomycetes) that transform sugars into alcohol. As we said before, by law selected yeast cultures can be added.
When the fermentation is over, the racking takes place: the so-called “flower-wine” is transferred to wooden or concrete containers where it stabilizes and acquires body and aromas, becoming wine in all respects.
The pomace is pressed to extract other wine (very rich in tannin and sugar) which is added or not to the flower-wine according to the desired characteristics.
After racking, the wine can undergo numerous treatments or “corrections” aimed at improving its commercial characteristics.
Blend: blending of two or more wines with different characteristics, in order to improve various properties (for example increasing the alcohol content).
Refermentation: it consists of refermenting the wine that still contains sugars, adding fresh marc or selected microbial cultures; this is done for those wines that need to acquire sparkle, such as prosecco, sparkling wine or champagne.
Concentration: takes place by bringing the wine to freezing temperature and separating the aqueous part that solidifies. In addition to blending, it is the only system allowed in Italy to increase the alcohol content.
Correction of acidity: occurs with the addition of acids (to increase it) or with the addition of bases (to decrease it).
Color increase: occurs by adding more peliphenols – substances contained on the peel that release color. Or by clarifying with the use of vegetable coals.
Correction of tannins: the decrease is carried out with the addition of albumin or gelatin, the increase with the addition of oenological tannin.
Clarification: it is carried out with filtration (mechanical or by adsorption), through albumin, gum arabic or with the cold.
Centrifugation: carried out after draining and pressing to remove the yeasts; during or after fermentation.
Clarification: once bovine blood, egg white or milk were added; currently, casein, gelatin, isinglass or mineral compounds such as bentonite, silica or potassium ferrocyanide and metatartic acid are used.
Refrigeration: consists of keeping the wine at temperatures slightly above freezing (from -4 to -8 degrees) for at least 5-6 days. In this way, various advantages are obtained: solubilization of any added carbon dioxide, increase in alcohol content, precipitation of unwanted substances, decrease in microbial load and premature aging processes.
Most of the wines are consumed the year following the vinification. Only a few are destined for aging: those with a high content of alcohols, polyphenols, acids, which greatly refine their organoleptic characteristics.
Aging usually lasts from 3 to 5 years, only very few wines withstand the test of additional time. After reaching the top of the organoleptic characteristics, the wine becomes “past” and begins a more or less rapid decline until it becomes undrinkable.
White wines are the least suitable for aging: most after 1-2 years take on a bitter taste, a rancid aroma and an amber color.
Aging usually occurs in two phases: the first in the presence of oxygen (in wooden barrels) and the second in the absence of oxygen (in the bottle).
The main transformations are:
- color: transition to brick-red and brown-yellow thanks to the precipitation of polyphenols;
- transfer of substances from the wood of the barrel;
- formation of acetals which give typical aromas and aromas of aged wine;
- resinification which gives the wine a resinous flavor.
To shed more light on the various types of wine production, I tried to summarize the basic notions in a few simple lines.
By definition, biodynamic wine is that wine obtained from grapes of biodynamic agriculture, a methodology formulated in the 1920s by Rudolf Steiner. Biodynamic agriculture is a type of cultivation that tends to preserve the naturalness of the soil and its products. All the innovations that have concerned agriculture are canceled and we go back to the origin, with a few more notions. The certified body by which biodynamic wines are recognized is private and is called Demeter.
In this cable only grapes coming from certified organic farming are used; this means that all pesticides, synthetic fertilizers, pesticides or herbicides are prohibited. Then there are agricultural practices that are born with the aim of preserving the fertility of the soil and sustainability.
The few products allowed in this type of agriculture must have certified organic origin.
The producer undergoes an evaluation process by a certification body for what concerns the entire production process; the wine can be placed on the market only if the outcome is positive.
In addition, all stages of production, from the vineyard to the bottle, are traced through suitable document flows and a logo will be placed on the label showing the certification of the product and the certification body that carries out the checks.
To date, there are no legally recognized and internationally shared regulations to be followed to produce “natural wine”. There are, however, producer associations (the French ones are the oldest and most well-known), including national ones, which bring together producers of natural wines and which aim to respect the association’s internal rules.
The so-called “natural” wine is generally produced by those small winemakers who, while adhering to all the “naturalistic” principles of organic and biodynamic agriculture, do not want to adhere to regulations, certifications, and the like.
In practice, they do not use synthetic products or invasive practices.
The philosophy of natural wine is conceived so that the product is obtained without using any of the substances allowed in winemaking by the other methods (apart from very low quantities of sulfur dioxide). Similarly, the common chemical-physical procedures of the cellar are not used for the treatment of musts and wines (allowed for organic wine, and some, for biodynamic).
Those who claim to produce natural wines often appeal to the concept of local wine, as a key to making wine respecting the cycles of nature and, above all, to favor the expression and typicality of the area (native vine, soil, climate, tradition ).
These are the general guidelines for a first approach to wine and everything that lies behind a bottle. As already mentioned above, I know well that every single passage written above should be deepened and dissected in its infinite details, but from personal experience I think it may be useful to understand broadly how to pass from grapes to wine, and then, at a later time, to be able to go into detail and learn even more.
The nice thing about this world is that you never stop learning and with every sip we always manage to appreciate something more.