Winemaking

Use of Sulphur

On February 7, 2008, in Use of Sulphur Dioxide, wine geeks, Winemaking, by ngorevic

Sulphur Dioxide is a very important compound in the winery, where it used as an antiseptic, an antioxidant, and to kill yeasts at certain times. Sulphur will kill bacteria that can form in the must and during the fermentation process. In most wineries, the natural yeasts present on the grape skins are killed with sulphur and then cultivated yeasts are used instead. It is again used after fermentation to make sure any yeasts in the wine are gone, which could affect the flavor of the wine.

Their is a certain myth you might hear about in the United States. This myth is caused by the label you see on every bottle of wine, that says " This product contains sulfites." I had been told at one point that the FDA requires the addition of sulphur as a preservative, when wines are imported from other countries. The idea is that when winemakers in Europe make wine to be sold in the United States, they are forced to add these nasty chemicals to the wine. Someone also told me that the lack of sulphites in foreign wines is the reason why when you drink wine in Italy, you never get a hangover. I can tell you authoritatively that this myth is absolutely false. Wines from Europe have just as much sulphur in them as wines made in the United States. There may be some small scale producers (like people who make wine in their garage), but you'd never see any of that wine here. Sulphur is indespensible in the winemaking process. It's use is very controlled by law, and the amounts that are used are very small. The amount of sulphur in one typical dried apricot, for example , is far more than what is in one entire bottle of wine. The only people that really need to be concerned about sulphur in wine are asthmatics, for whom sulphur can provoke all kinds of nasty symptoms. These people are the reason we have the label in the United States. Because of our litigious nature, wineries must protect themselves against the possibility of an asthmatic suing for damages. As for the reason you don't get a hangover in Italy, I suspect it may have something to do with the amount of food you eat there, and perhaps even that the food is much fresher and therefore nutrient-rich, counteracting the deleterious effects of alcohol. But you'll have to decide for yourself on that one.

Chaptalization

On February 7, 2008, in Chaptalization, wine geeks, Winemaking, by ngorevic

Sometimes when grapes are grown in cooler climates, the sugar level in the grapes will not be high enough to produce enough alcohol to make good wine. In this case, although it is usually legally controlled, a process called chaptalization is used. Chaptalization is named after Comte Chaptal, the Napoleonic Minister who invented it. In this process, sugar is added to the must, either before fermentation or during it. This additional sugar will convert to alcohol the same way the natural sugar inside the grapes will, so the alcohol level will be slightly increased. Chaptalization, when done in moderation, can produce an excellent wine. If it used too much, however, the wine will taste too strong, as the alcohol level will be out of balance in comparison to the amount of fruit in the flavor.

Tagged with: Chaptalization

Must

On February 6, 2008, in wine geeks, Winemaking, by ngorevic

Must is a term that refers to the grapes as they maker their way through the various processes in the winery, before they are fermented. Basically must is another word for grape juice in the winery.

Tagged with: Glossary

Getting Juice out of the Grapes

On February 6, 2008, in Getting the juice out of the grapes, wine geeks, Winemaking, by ngorevic

After the grapes are harvested, when they arrive at the winery, they are put on conveyor belts, where workers pick out unripe grapes and other undesirable foreign particles. To get the juice out of the grapes, they must first be crushed, and then pressed. Usually a machine called a crusher/destemmer will remove the stems and crush the grapes just enough to puncture the skins. Some juice will run off the grapes (called "free run juice") and be collected. A limited number of wines are made from free run juice only. From there, the grapes will enter a press. The most modern and frequently used press today is a horizontal press, that has an inflatable plastic bladder inside it. The outside of the press has slots in it, so as the bladder gradually expands, the juice runs out of the slots. This pressing process happens slowly, so as to avoid crushing the pips which would release their bitter flavor.

Grape Parts

On February 6, 2008, in Grape parts, wine geeks, Winemaking, by ngorevic

A grape is made up of several different parts. Most of the grape is made of water, and this water eventually ends up in the wine. In fact, in ancient times, wine was an excellent source of clean water, which added to its popularity. Grapes also contain sugar, pips (seeds), skin, and pulp. All of these parts are important when it comes to making wine:

Sugar's role in winemaking comes into play during fermentation, because yeast processes sugar into alcohol. The amount of sugar in the grapes is very important, as an indicator of ripeness. There are several different scales used to measure ripeness in vineyards, depending on the vineyards location in the world. In France, they use the Baumé scale, in Germany, Oechsle or KMW, or Brix in California. All of these scales measure the must weight, or the density of the juice inside the grape. All of these scales provide an approximate judge of how high the alcohol content of wine will be from a given grape. As the harvesting season approaches, workers will comb the vineyard testing grapes on one of these scales, and the winemaker will use this information to decide when to harvest.
The pulp in almost all grapes, including black grapes, is colorless. You might think that black grapes have a dark pulp and excrete dark juice, but in fact all grapes juice looks like clear grape juice.
The color of red wine instead comes from the dark skins, that are soaked in the juice for a time during fermentation to provide that color as well as tannins.Grape skins also have natural yeasts living on them, which start the fermentation process once the grapes are crushed.
The pips, or seeds, inside grapes contain tannins, but also a bitter astringent flavor that does not taste good in wine. For this reason, grapes must be crushed carefully, so the pips are not broken. With modern winemaking advances, this is rarely a problem today.

On February 6, 2008, in wine geeks, Winemaking, by ngorevic

Winemaking, or Vinification, is the process of turning the harvested grapes into wine. Sometimes the vitculturist and the winemaker are the same person, and sometimes not. You can't make really good wine from bad grapes, but you can make bad wine from good grapes, so vinification is just as important as viticulture. If the winemaker is not the same person as the vitculturist, they will need to work closely together at harvest time, to make sure that the grapes arrive at the right time. This is particularly complicated in larger operations, as the different grapes will reach ripeness at different times, and as the winery will have a limited amount of grapes it can handle at one time. The workload must be organized so the grapes are processes in a timely fashion.

Noble Rot

On January 30, 2008, in Making Sweet Wine, Noble Rot, Viticulture, wine geeks, by ngorevic

Noble Rot is a form of the botrytis cinerea fungus that can form some of the greatest sweet dessert wines in the world. For this to happen, the exact right conditions must develop, and there are only a few places in the world where this happens, most notably in Bourdeaux (Sauternes) and Germany. It requires damp mornings and dry afternoons. When this happens, the rot attacks the ripe grapes, and eats the water inside the grapes without breaking the skin. By sucking out the water, the sugar in the grape becomes concentrated, allowing a wine to be produced that is both high in alcohol and sugar. In addition, the fungus flavors the wine in it's own special way, adding notes of honey and marmalade. This process is tricky, and requires a great deal of hand-picking. Pickers must go through the vineyard several times, each time picking only those grapes that are affected by the rot in just the right way. Some years the fungus just isn't created, and entire crops are lost. Because of the unpredictability, and extreme level of care required to produce these wines, they are always very expensive. And they are amazing!