Winemaking – the Perfect Combination of Art & Science
Mother Nature provides the ingredients and the winemaker, using a combination of techniques, turns the beautiful grapes into a delicious sip. Creating remarkable wines is made up of a series of basic components as well as endless variations along the lengthy and complex road. Discover the basics of the winemaking process with an overview of the important steps.
Winemaking begins in the vineyard. And pruning is a vital component, as it controls the health, growth and yields of the wine. Generally done in the winter from December to March, pruning manages the vine by removing excess branches, canes or foliage. It keeps grapevines healthy and productive, and the timing and method can enhance certain aromas and alter the acid content of the wine.
One of the most critical steps is the harvesting of the winegrapes. Sonoma County’s harvest typically begins in August and ends in October. The weather helps shape the timetable and the exact time of harvest is determined by a combination of science and tasting. The ripeness of the grape is measured by sugar, acid and tannin levels to find that perfect balance. Winemakers base their decision of when to pick on the style of wine they wish to produce.
Crushing & Pressing
Once the grapes are sorted, it’s time for de-stemming and crushing. Crushing occurs before fermentation, bursting the skins so that all of the inner solids can be exposed to fermentation. Freshly pressed grape juice that contains the skins, seeds, and solids is called wine must. After the wine must has fermented for 5-7 days, the grape presses begin pressing the wine must, extracting the juice.
For white wine, the winemaker quickly crushes and presses the grapes to separate the juice from the skins, seeds, and solids; preventing unwanted color and tannins from leaching into the wine. Red wine is left in contact with the skins to acquire flavor, color, and additional tannins.
Alcohol is produced by the process of fermentation. Yeasts transform sugars present in the must (or juice) into ethanol and carbon dioxide and can begin fermenting naturally within 6-12 hours. Fermentation continues until all the sugar is converted into alcohol and dry wine is produced. To create a sweet wine, wine makers will sometimes stop the process before all the sugar is converted. Fermentation can take anywhere from 10 days to one month or more.
Once fermentation is complete, clarification begins and solids such as dead yeast cells, tannins, and proteins are removed. Wine is then transferred or “racked” into an oak barrel or a stainless steel tank.
Fining occurs when substances are added to the wine to clarify it. Winemakers will often use egg whites, clay or other compounds to wine to help move dead yeast cells and other solids out of the wine. The substances adhere to the unwanted solids and are forced to the bottom of the tank. A filter captures the larger particles in the wine and the clarified wine is racked into another vessel and prepared for bottling or future aging.
A winemaker has two options at this stage: bottle the wine immediately or give the wine additional aging time. Further aging can be done in bottle, in stainless steel tanks, oak barrels or other vessels. Aging the wine in oak barrels produces a smoother, rounder, and more vanilla flavored wine. It also increases wine’s exposure to oxygen while it ages, which decreases tannins and helps the wine reach its optimal fruitiness. Steel tanks are commonly used for white wines.
Before bottling, different batches of wine can also be mixed to achieve the desired end product. The winemaker can combine wines from different grapes and batches that were produced under different conditions. These adjustments can be as simple as adjusting acid or tannin levels, to as complex as blending different varieties or vintages to achieve a consistent taste.
The final step, and very important to the finished product. Bottling involves timing, vessel type and closures—natural cork, synthetic cork, or screw cap. Each impacts the amount of time needed for bottling and can have different benefits for the wine.