Have you ever tasted good wine, like- really good wine? What did it taste like, and what happened to your body? If you’ve tasted good wine, you’d know that it’s quite difficult to explain the feeling as the only thing you’d likely say is- it is perfect! Frankly, that’s the best way to explain wine that is processed.
Of course, more serious wine enthusiasts and connoisseurs will in most cases be able to tell the exact fruits used to make a certain wine immediately it settles on their taste buds, and they are also able to describe the taste. But for regular people, “perfect” works just fine.
Speaking of regular people, for most, wine seems to be a type of luxury that is only consumed on special occasions, and this idea is quite understandable. It’s understandable because really good wines can be quite expensive. On that note, it is worth mentioning that a bottle of 1945 Domaine de la Romanée-Conti once sold for a ludicrous amount of $558,000 at an auction in 2018. This type of wine is usually stored with special wine storage methods and have been left to age for a long while.
Don’t be alarmed, prices like these aren’t very common and it’s actually possible to get somewhat decent wines for as low as $35. When it comes to wine pricing, it really is about the process of making them. Age also is a factor as older wines tend to be more expensive than newly produced ones. It is believed that the older it gets, the better it tastes.
Before anything, let’s get all the major terminologies associated with wine out of the way. First, winemaking is also called vinification and it entails the entire processes involved it its production. The science of winemaking is oenology, viticulture is the growing of grapes, which is the main ingredient in most wines, and finally, a person who makes wine can be called a winemaker or a vintner.
There two types of wines that are produced today. They are still table wines (produced without carbonation) and sparkling wines (produced with carbonation). In this article however, we’ll only be looking at the processes involved in still table wines or non-sparkling wines, as they may also be called. These processes include:
- Juice separation
- Aging and bottling
In winemaking, fresh, fully ripened grapes are the best raw materials. Sometimes, however, these grapes may be harvested before they are fully ripened and mature. This premature harvesting is commonly found in the eastern parts of the United States, and in northern Europe where there isn’t enough heat to aid in the full maturing of grapes.
Grapes that are harvested prematurely usually have a sugar deficiency. This deficiency is corrected by adding grape juice concentrates or by directly adding sugar.
In wine production, the timing of harvesting is key. This is because in grape composition, premature harvesting often results in thin, low-alcohol wines, while late harvesting may lead to high-alcohol, low acid wines.
During harvesting, grapes are cut from the vine and transported to the winery. In Europe, they are placed in large tubs for transporting while in the California and other parts of the world, they are transported in metal gondola trucks. The most common method of harvesting is the mechanical method which involves breaking the vine stems or shaking the berries loose from the clusters. Once the grapes reach the winery, they are carried into the crusher.
In ancient times, grapes were crushed by treading with shoes or with bare feet. Today, thanks to technology, the process is much faster and less pain-staking as harvested grapes are crushed with a dedicated machine called a crusher-stemmer. This machine consists of a perforated cylinder with paddles that revolve between 600 and 1200 revolutions per minute.
This machine saves time as it does both the stemming and crushing at the same time. Before the advent of this machine, the grapes would go through the stemming process before being crushed. In the crusher-stemmer, the berries are crushed and allowed to fall through the perforations of the cylinder.
During this process, most of the stems go out through the end of the cylinder. In the extraction of juice from the grape berries, crushing isn’t always employed, especially in the production of white wine from red grapes. In this case, berries are pressed and not crushed. This process is common in the Champagne region of France.
The crushing stage is very important when it comes to coloring in winemaking. As earlier mentioned, when red grapes are used to make white wine, they are pressed and not crushed. This is done so that the liquid doesn’t mix with the red pigment of the berries. Also red grapes may also be placed into tanks and closed to kill its skin cells, which then allows for easy and seamless color extraction.
There are two main procedures employed in juice separation. One is placing the already crushed grapes in containers that have false sides and a false bottom and are designed to drain juice. Juice that come out from this process are called free run juice. The second is by placing the crushed grapes in a press.
The horizontal press is more commonly used today because it applies pressure on both sides making the process faster. For drain pulps however, the continuous screw-type press is mostly used, while for white musts, the Willmes press is largely used. The Willmes press is made up of a perforated cylinder that has an inflatable tube. In this method, the tube is inflated after the crushed berries are thrown into the cylinder. The inflated tube presses the grapes against the sides of the rotating cylinder, causing the juice to flow out through the perforations. With this method, pressing can be done efficiently without the use of manual labor which is used in traditional basket pressing. Click here to learn more about wine pressing.
In the production of red wines, continuous presses in which seeds, juice, and skins are fermented together is more practical and largely employed. In this process, juice separation is made very easy because the skins become less slippery after fermentation. Also, as opposed to unfermented musts, the quantity of free run juice is much greater.
Once the juice is fully separated from the must, fermentation is allowed to take place. Naturally, if the juice is left on its own, it will begin fermenting with 6 to 12 hours with the help of yeasts in the air known as wild yeast. Some wineries employ this natural fermentation process, however, for some reasons, many vintners prefer to use a strain of yeast of their choosing. One of such reasons is that natural fermentation with the aid of wild yeast is often unpredictable, but in the case of artificially added yeast, the end result is usually predictable.
Regardless of which fermentation method is employed, the process is allowed to continue until all the sugar present in the juice is converted to alcohol. The duration of the fermentation may be as long as a month or more in some cases. The level of alcohol gotten however, isn’t determined by the duration of the fermentation period, but by the quantity of sugar contained in the must. It is interesting to know that in the production of sweet wine, the fermentation is stopped before all of the sugar is converted into alcohol. When it comes to alcohol levels, in cool climates, 10% is considered normal as is an alcohol level of 15% in warmer regions.
After fermentation, the clarification process is started immediately. In this process, dead yeast, proteins, and tannins are removed from the wine. This process is either done in stainless steel tanks or in wooden barrels. The clarification process involves both the filtration and fining processes.
In fining a substance is added to the already fermented wine to aid clarification. It mostly involves adsorption, chemical reaction, and physical movement. When fining agents like gelatin or bentonite are added, protein cells and dead yeast are adsorbed. With gelatin and tannins, adsorption of suspended compounds may accompany chemical reactions. Some level of clarification will occur when silica or any other inert material is added to a cloudy wine.
In ancient times filtration was done using clothes with rough screens. The wine is poured through them and the residues are left on the cloth. Today, filtration is done using filter pads made of cellulose fibers that have varying porosities. Some filters have pore sizes that are small enough to get rid of yeast cells.
Through refrigeration, yeast growth can be prevented as low temperatures are unfavorable for yeast growth. Also, lower temperatures help to speed the precipitation of potassium acid tartar or cream of tartar which is important because when the cream of tartar precipitates slowly, it causes cloudiness. To induce this quick precipitation, the temperature is usually lowered to temperatures between -5 and – C for one or two weeks.
Many wines often contain some protein that causes clouding by precipitation and sometimes by reacting with metals like copper to form aggregates which also form clouds. As earlier mentioned, protein could be removed by adding bentonite, however this process is accelerated when the wine is heated. Although seldomly employed in modern wine clarification, protein may be precipitated by pasteurization done between 70 and C.
Aging and Bottling
The quality of many wines improves as they age. This is because with time, acidity decreases, the wine stabilizes, and there is further clarification as more unwanted substances are precipitated. Aging of wine is usually done in wooden oak barrels to allow the escape of oxygen, alcohol, and water. All of these combine to improve the aroma and flavor of the wine.
When wine is bottled, it is done precisely to prevent as much oxygen as possible as from entering the bottle. In wine bottling, there are two methods usually employed. The first involves filling the bottle from the bottom with a tube inserted into it; this method is called bottom filling. The second method involves first flushing the bottle with carbon dioxide before it is filled. Visit https://www.wired.com/2014/10/whats-wines-tastes-better-age/ to understand why aging improves wine taste.
The processes involved in the production of sparkling wines are slightly different. Basically, carbon dioxide is prevented from leaving the must during fermentation. Champagne is a very popular sparkling wine and costs much more than regular sparkling wines.