Grapes Flashcards
(32 cards)
What are the main components of a grape?
Skins, pulp, seeds, water
What do the skins contribute to the wine?
Tannin, color, flavor
What do tannins contribute to the wine?
Lend structure but also astringency (dryness) and bitterness to red wines
What causes astringency?
Phenolics
What does color contribute to the wine?
Provides an intensity and hue from molecules located in the skins that are different for each grape variety
What does flavor contribute to the wine?
The most important aromas and flavors are found in the skins of the grapes and are unique to each variety. The differences come from the thicknesses of the grapes
What are the components of the pulp?
Water, sugar, acids, seeds/pip
What happens to sugar levels as grapes ripen?
Sugar levels increase as grapes ripen
What happens to acid levels as grapes ripen?
Acid levels decrease as grapes ripen
What do the seeds/pip contribute?
They can add unwanted bitterness if crushed. Winemakers try very hard not to damage the seeds when crushing grapes
What is the process of changing sugar and acid levels called? This process is also when the grapes start to get color in the skins.
Veraison
When does Veraison occur?
40-60 days after fruit set
Why does veraison occur?
Carbohydrates in the roots and trunk transfer sugars to the berries. Sucrose is converted to glucose and fructose.
How can one tell from the seeds when grapes are ready from a tannin perspective?
The seeds turn a nutty brown in color
What is the genus of wine grapes?
Vitis
What is the species of wine grape most wines are from?
Vinifera (Vitis vinifera)
What other species of wine grape can be made into wine?
Vitis labrusca
Vitis riparia
(both native to N. America)
Where is Vitis vinifera from?
Mediterranean, Europe, SW Asia
How many varieties of vinifera exist?
over 10,000
What are the 8 international grape varieties?
Chardonnay, Riesling, Sauvignon Blanc, Pinot Gris
Cabernet Sauvignon, Pinot Noir, Syrah, Merlot
What is important to consider when matching grapes with a potential planting location?
Local wine laws: can this variety even be planted here and/or use the regional appellation name on the label?
Is the grape compatible with the climate? Will it ripen? Or will it get too ripe and become out of balance?
Is the grape compatible with the soil? Does the soil help the grape ripen properly?
Marketability: will you be able to sell the wine you make?
What is viticultural propogation?
Grape vine breeding
What is a vine hybrid?
Vines of two or more different species are are combined to produce a new variety (vinifera is combined with labrusca)
What is an example of a hybrid?
When european species were combined with America labrusca species to help with the phylloxera outbreak. This, however, did not take off and only 5% of global wine grapes are hybrids.
Vidal Blanc, sometimes compared to riesling, cross of Ugni Blanc and hybrid Rayon d’Or. Grown around Great Lakes, Finger Lakes, Ontario, and produces dry and ice wines
