Lesson 2 The Vineyard From Soil to Harvest
Objectives After reading this chapter, you should be able to display an understanding of how grapes are grown for wine production. describe the annual growing cycle of a grapevine. explain how the grapevine s environment affects the crop it produces.
Introduction Great wines are made from great grapes, and the ultimate quality of a wine is determined in the vineyard as much as it is at the winery. Many fruit crops are grown with an emphasis on appearance. Premium wine grapes are one of the few crops that are still grown primarily for their flavor.
Factors that affect the vineyard There are two factors that influence the character of grapes from a given vineyard: environmental and cultural. Environmental factors are all the natural attributes of the vineyard site. Cultural practices are all the actions performed by the grower.
Grapes Used for Winemaking Grapes are the preferred fruit for wine production. Grape juice has all the attributes necessary for fermenting the juice. The outside of the grape berry is covered with a waxy layer that contains naturally occurring yeast. The great majority of wine produced in the world is from grapes.
Vitis vinifera There are many species of grapes worldwide, but the overwhelming majority of wine produced is from the species Vitis vinifera. This species is native to Asia Minor. Within the species Vitis vinifera there are over 5,000 named cultivars; only a fraction are grown commercially.
Soil and Site Soils that are shallow or low in nutrients will put pressure on the grapevines resulting in lower cropload with less vegetative growth. If there is less vegetative growth, the grape clusters will not be as shaded by the leaves; sun exposure on Cabernet Sauvignon clusters will give them more fruity aromas and less of a herbaceous aroma. Grapes grown in fertile soils can also produce high-quality fruit, but they must be managed properly.
Soil and Site (continued) There are a number of parameters that go into a soil s makeup: The parent material or rock of which it is comprised The size of the particles the soil is made of The chemical composition of the soil The organic matter and nutrients in the soil The depth of the soil
Soil and Site (continued) A vineyard on a south-facing hillside will absorb more sunlight and be warmer than the north side of the hill. Grapevines need adequate, but not excessive, nutrients from their soil for healthy growth. Hillside vineyards have better drainage but will be more susceptible to erosion and wind damage. Cold air will settle into valleys and low-lying areas on still mornings without wind making these locations more susceptible to spring frost and winterkill.
Climate Climate has a great influence on wine grape quality. Grapevines do best in temperate zones between 25 and 35 Celsius. Grapes also require adequate rainfall or irrigation to support growth and crop development.
Climate These broad weather conditions of a particular wine-growing region are defined as the macroclimate. The weather in a particular vineyard or portion of a vineyard is referred to as the mesoclimate or microclimate.
Techniques of Grape Growing Before the vineyard is planted, the site must be chosen and prepared for planting the grapes. The soil can be tested and amendments to it can be inserted it if necessary. Pests and diseases can be controlled by using a rootstock that is resistant to them or by fumigating the soil before planting.
The Growing Season Grapevines lose their leaves and go dormant over the wintertime. A dormant vine is more tolerant of cold temperatures This dormancy creates an annual cycle of the growing season that begins in the spring and ends in the fall after harvest.
The budbreak Bud break is when the grape starts its annual growth cycle. Tiny buds on the vine start to swell and eventually shoots begin to grow from the buds. The growing season begins in the early spring usually between February and April in the Northern Hemisphere. When the average temperature reaches 50 F (10 C), the vines end their winter dormancy.
Bloom Flower clusters at the base of the young shoots look like miniature clusters of grapes. About eight weeks after budbreak, they begin to bloom. Once fertilized, a grape flower will begin to develop into a berry. If a flower is not fertilized, it will drop off the cluster in a process called shatter. For optimum pollination, warm, even temperatures are desired, without too much wind or wet weather.
Véraison Véraison is the beginning of ripeness and starts in mid to late summer about eight to ten weeks after bloom. At véraison: The hard and green berries begin to swell and change color. The sugar from photosynthesis is now going into fruit development instead of vegetative growth. Irrigation is diminished to help the fruit ripen by slowing vine growth.
Harvest Six to ten weeks after véraison the grapes will be ready for harvest. The time of harvest depends on the variety, the weather conditions, and the degree of ripeness desired. To determine when the grapes are ready to be picked, samples are taken and analyzed for flavor, chemistry, and appearance. The decision to harvest is based on the maturity of the fruit as well as operational concerns.
Harvest (continued) Grapes can be picked either by hand or by machine. Hand picking is gentle to both the fruit and the vines is selective: only the healthy ripe fruit is picked requires more labor
Harvest (continued) Mechanical harvesters are not as gentle or selective. have the advantage of also being operated at night so that they will bring in cooler fruit. require less labor (more cost-effective). Both methods, if done properly, can provide the winery with high-quality fruit.
Dormancy At the first frost after the harvest, the leaves will fall off marking the beginning of the winter dormancy period. While the vine is dormant, no new growth occurs and it is much less sensitive to cold weather. Vineyard operations during dormancy include adding fertilizers and soil adjustments. a cover crop that may be planted to control erosion. pruning the vines.
Pruning After a vine is established, the process of pruning removes almost all the new growth from the previous year. Each bud left on the vine will produce a new shoot in the spring, and the amount of the next season s crop is determined by the number of buds.
Pruning (continued) The most important concept in pruning is balance. This is where the vine is left with the appropriate amount of buds to produce the correct cropload. Overcropped vines will have a difficult time producing enough sugar to get the grapes ripe. Undercropping also has undesirable consequences because if there is not enough crop the vine will put too much energy into vegetative growth.
Organic Viticulture Organic viticulture is the practice of growing grapes without the use of any manmade substances. In an organic vineyard, weed control is done by tilling or planting of cover crops. Elemental sulfur can still be used to combat rot, but synthetic chemicals cannot be used. Excellent grapes can be grown organically, but the extra handwork required makes them more expensive to grow.
Sustainable Viticulture Sustainable viticulture promotes agricultural practices that allow the minimal use of pesticides in the vineyard. This encourages the development of a natural vineyard ecosystem with predatory insects to help combat grape pests. Sustainable grape growing is a popular option because it provides much of the benefits of organic farming, with less risk and a lower cost of labor.
Major Grape Varieties Although there are thousands of varieties of Vitis vinifera that are grown for winemaking, only a few make up the vast majority of production.
Cabernet Sauvignon The classic variety of Bordeaux, it is one of the most popular varieties grown worldwide. It is a late season ripener with loose clusters and thick-skinned berries that make it resistant to rot. It is known for its excellent color and tannins combined with complex flavor. In 1997 DNA research determined that Cabernet Sauvignon is a cross between Cabernet Franc and Sauvignon Blanc. While 100 percent of Cabernet Sauvignons are often made with great success, blending with other Bordeaux varieties makes a more balanced and complex wine.
Chardonnay One of the best known white varieties, Chardonnay comes from the Burgundy and Chablis regions of France. It is a mid-season ripener allowing it to be grown in cool regions. A versatile variety can be made in a number of styles. Chardonnay s popularity resulted in extensive planting in California throughout the 1980s and 1990s.
Grenache Grenache is the most popular grape in the Southern Rhône Valley, where it is the mainstay of the Rhône blend Châteauneuf du Pape. It has ripe, fruity, plum-like flavors with moderate tannins qualities that make it useful for blending with Syrah, which can be more tannic. It thrives under warm growing conditions and can support a large cropload on fertile soils. In cooler areas with a lighter crop, it produces much better wine.
Merlot Merlot is from the Bordeaux region where it is sometimes made into a wine by itself, but more often is blended with Cabernet Sauvignon. It has similar flavors to Cabernet but has a softer mouth feel and gets ripe earlier in the season. Merlots have become popular because the good flavors and the lighter body make it more approachable with novice wine drinkers. Its consumer acceptance has made it one of the most widely planted grapes in California. Its success has led to overplanting.
Pinot Gris/Pinot Grigio This is known as Pinot Gris in France and Pinot Grigio in Italy. The parent of Pinot Blanc, Pinot Gris itself is mutated from the red variety Pinot Noir. Although it produces a white wine, the clusters have a light pinkish/brown color. It is an early season ripener and is popular in cool regions with short growing seasons. It is currently one of the fastest growing varieties in America in terms of consumption, due to imports as well as new plantings.
Pinot Noir The primary grape of Burgundy, it has a reputation for producing excellent, long-aging wines. It also has a reputation for being both difficult to grow and make into wine. Pinot Noir has many clones, from those that are suited to sparkling wine production to Burgundy clones for table wine. It ripens early and does best in cool conditions. It is a delicate wine and must be treated very gently at the winery so that the balance and flavor is not lost.
Summary Growing premium wine grapes is collaboration between the winemaker and grower. The vintner lets the grower know what qualities are wanted in the fruit, and the grower manages the vineyard in a way that will deliver them. Market conditions in the wine business also affect prices where popular varieties in high demand to the consumer are worth more than varieties that have fallen out of favor.
Summary (continued) The best grapes are usually produced from vineyards that have a long and mutually beneficial relationship with the winery. In these situations, a trust between the grower and the winemaker develops, and the grower knows exactly what kind of fruit that the winemaker wants.