The Wine Making Process Joins Science And Art
Written by Tim on April 17, 2013
Making wine joins scientific technique and artistic blending of ingredients in a process similar to cooking. Wine makers can ferment all types of fruit to make wines, but 99.9% of the world’s wines come from grapes, which make the most popular vintages with the subtle flavor notes that aficionados appreciate. Grapes grow in many regions, but France, Australia, Chile and California wines enjoy the most favorable appraisals by wine experts.
Wines get their names and flavors from the types of grapes used and the soil and weather where the grapes grow. In the northern hemisphere, grapes bud in late March and continue to develop throughout the summer. Vitis Vinifera grapes include Chardonnay, Merlot, Riesling, Cabernet Blanc and Cabernet Sauvignon, which grow in European climates. Hybrids include Chambourcin, Vidal Blanc, Blanco Noir, Villard Noir and Seyval Blanc, and these grapes grow well in France and the United States. American grapes include the Concord, Delaware, Niagara and Catawba, and they come from the Vitis Labrusca family. Grapes from the Vitis Rotundifolia family, such as Scuppernog, Magnolia and Carlos, grow well in warmer regions not usually known for wine making.
Grape Harvesting Yields to Modern Technology
The classic wine making techniques of past centuries included crushing the grapes by foot, but modern technology and health concerns have changed this practice. After the harvest, the slurry of crushed grapes and their juices gets treated with antimicrobial chemicals, nutrients and yeasts to begin the fermentation process. The slurry of grapes, yeast and juice is called must.
At this point, grapes get separated into white and red wine varietals. Grapes destined to produce white wines have the skins and stems removed. Red wines include the skins, which provide the tannins that produce the deep red colors of fine wines. Fermentation takes place in large casks, stainless steel tanks or oak barrels.
Fermentation is the process by which yeast converts sugar into alcohol and carbon dioxide. Some grapes have enough sugar naturally, but wine makers add sugar to other varieties to increase the alcohol content of the finished wine. Maceration describes contact between the grape skins and juices. During active fermentation, the skins often rise to the top of the must and form a cap. Wine makers want to maximize color and flavor extraction, so they punch the cap and remix the solids and liquids. Some devices spray the juices over the floating caps. Both techniques release heat and intensify flavors.
Blending Produces Distinctive Vintages
Accomplished wine makers blend grapes, sugar content and chemicals to achieve the right balance of acidity, sweetness and flavor, a subjective process that each wine drinker performs personally by selecting wines for meals, social occasions and celebrations. Wine makers adjust pH levels, sugar content, acidity, and grape percentages to improve color or add distinctive flavor notes.
Acidity levels make a tremendous difference in the finished wines. The pH balance influences flavor because lower acidity increases oxidation that enhances flavor. High-acidity levels resist bacterial infections that could spoil wines. Blenders add acids to the must to adjust pH levels to achieve the perfect balance of flavor, color and safety.
Oak adds flavor and allows small amounts of oxygen to interact with the wine during the fermentation process. However, oak casks and barrels don’t last forever, so stainless steel tanks have become increasingly popular for wine fermentation. Wine producers often add oak chips to the must to introduce the flavor notes that fermentation in oak traditionally imparts.
The yeast eventually convert all the sugar into alcohol, and the tanks allow the owners to remove the liquid from the settled solids for secondary fermentation. This process allows a bit of aeration that further develops flavors. Once fermentation has finished, wine makers face the challenge of clarifying wines, which describes removing unwanted particulates that float in the liquid.
Filtering removes most of the particles and adding egg whites binds the froth to smaller particles and helps them settle on the bottom of tanks, removing dead yeast cells and other debris that make wines appear cloudy. The result is a bright, clear and sparkling vintage that appeals to the eye, nose and palate.
Final Aging and Bottling
The vintners age wines in temperature-controlled environments to develop flavors. White wines typically age for six months before bottling. Red wines often take one or two years to develop their flavors fully. Oak barrels add tremendous flavor during this time.
During the process, carbon dioxide helps extract flavors and color from the grapes. Yeast converts sugar into alcohol, but the process also produces residual heat. Wineries cool the fermenting must to prevent flavors from evaporating during fermentation. Chilling the wine to 28°F helps turn sediment into crystals, which wineries remove by filtration and clarification.
In about six months, the wine clears and all fermentation stops. At this point, the wine gets siphoned into sterilized bottles and corked. People store wine bottles on their sides at 55-degrees Fahrenheit to preserve the flavors, and many wines age well because flavors continue to intensify during storage.
Flavor Distinctions Come from Growing Conditions
The viticulture process involves complex interaction among several influences. Soil, water, light, grape type, geology, topography and chemical additives affect the flavor of finished wines, and consumers enjoy the benefit of choosing wines that fit their personal flavor preferences.
Growers must stay vigilant for signs of disease, drought, and insect pests to ensure strong grape harvests. Ideal conditions produce superior vintages that oenophiles cherish. The growing conditions, local culture, raw materials and wine making traditions influence the flavor of particular vintages, so consumers often appreciate their wines by knowing a little something about how they get made.
Leaves, Herbs and Flowers Create Signature Flavors
Wine makers often blend grape varieties to get distinctive flavors, and some add herbs and flowers from the local ecologies to complement flavors. Oxygen and bacteria exposure could ruin a vintage, so consumers taste each bottle after uncorking to ensure that the wine has survived its astonishing journey intact. Each bottle of wine tells a unique story of the growing, fermentation and bottling process, which is why people sample uncorked wines to make sure the bottles haven’t turned. Tasting the wine means the story has reached its climax. The tasting process is anything but routine because it introduces vintages and palates, capping an extraordinary process.