Learning Outcome 1 Flashcards
What does the skin of the grape provide to the winemaker?
Tannin - thin skin less tannin, thick skin high tannin
(Thin skin can be susceptible to splitting and rot like noble Botrytis)
Colour - red wine making
Flavour
What do the seeds and stems of a grape do
High levels of tannins, if handled roughly then can make the wine taste bitter
What does the pulp of the grape contain?
Made up of water and sugar. Contains acids and sugars
What does a vine require to grow
Sunlight
Warmth
Nutrients
Water
Carbon dioxide
What are the steps of grape formation
Flowering - spring the vine starts to grow it produces a cluster of flowers
Fruit set - once the flower has been pollinated it starts to grow seeds and begin to swell. This is now a grape. Newly formed grapes are small, hard, green and unpleasant to taste
Veraison - by mid summer the grapes have grown large enough that the vine can start the ripening process. Ripening starts with veraison which is the point grapes start to lose their green colour. White grapes become golden and black grapes become red and then purple.
What are the key stages of ripening
Unripe grapes
Ripe grapes
Extra ripe grapes (late harvest/raisined)
What happens to a grapes component as it ripens
At the start of the ripening grapes have very high levels of acid, hardly any sugar and an unattractive herbaceous flavour
Grapes then swell with water and become soft and fleshy
The acidity drops and the amount of sugar rises
As a grape ripens the herbaceous flavours decrease and the signature flavours of the grape develop.
For some white grapes the flavours/aromas change from green fruit to stone fruit to tropical fruit.
Black grapes change from fresh fruit to cooked fruit. Tannins ripen in black grapes. Must be ripe at the time of harvest as can taste bitter
Extra ripe grapes explain the change in grape development
Develop exaggerated ripe aromas and high sugar levels.
After a longer period the grapes turn into raisins as the water content evaporates. This concentrates the acids and sugars.
Dried fruit aromas start to develop
Commonly used to make sweet wines
What is botrytis/noble rot?
Botrytis is a fungus that can grow on ripe grapes.
Makes holes in the skin which causes the water to evaporate.
Ideal conditions if wanting noble rot would be damp misty mornings to allow the growth of fungus followed by warm dry afternoons to limit the growth to prevent it from destroying the grape.
Sweet wines
Tell me what you know about frozen grapes
Healthy grapes are left of the vine through summer and into winter.
When the temp drops sufficiently the water in the grapes freezes.
The grapes are picked while frozen and are pressed before they thaw.
When they are pressed, the ice crystals, along with the skins can be separated from the small amount of remaining unfrozen liquid
This liquid contains high concentrations of acids, sugars and flavours.
Known as ice wines and are sweet
What are the types of climate and what temperature?
Cool 16.5 or blow
Moderate 16.5 to 18.5
Warm 18.5 to 21
What climatic influencers that can effect how your grapes grow
Latitude - closer to the equator too hot. 30-50 degrees north or south are perfect
Altitude - temp drops at a higher altitude
Seas - regions with warm climates by the sea can benefit from cold ocean currents. Conversely vineyards of Northern Europe benefit from a warming influence of warm ocean currents
Rivers - take longer to warm up and also longer to cool down than land. Rivers can be warmer than land providing warmth in cooler regions, helping protect against frost and extending the ripen period. Reflect sunlight which can help ripening.
Air - cool air from the seas and mountains can benefit vineyards. Warmer coastal areas can benefit from cooling breezes from cold seas. Cold air from mountains can move down to lower altitudes at night.
Cloud/fog/mist - all are water vapour that can be seen in the air.
Clouds form above ground level and can block sunlight which slows down photosynthesis. Helps in places like Australia.
Fog forms at ground level and cools down a vineyard. Fog is helpful in California and chile
Mist is a less dense form of fog. Mists that form near rivers during mornings in autumn are essential for botrytis/noble rot.
Mountains - act as a barrier sheltering vineyards from clouds, cold winds and rain. Protection from mountains result in sunny summers, dry autumns and extended growing season.
Slope and aspect - south/ south east or facing the equator will produce riper grapes
Soil - provides the wine with nutrients and water. If many stones on the surface of the soil can absorb heat and warm the vineyard
What weather influences can effect wine growing?
Drought - vines need water, grapes won’t ripen
High levels of rain - can dilute the flavours
Hail - can cause significant damage to vines and grapes.
Frost - can damage and kill the vines new growth in spring
What are the grape growing options
Training - majority trained on trellises
Pruning - typically pruned in winter when dormant. Ensure individual vines retain their shape
Irrigation - flooding the field, putting systems in place for individual vines but this is expensive
Managing weeds, pests and diseases -
Can keep larger animals and birds away using nets or fences. Chemical sprays used for
Yield - amount of fruit produced per unit of area. Some areas have maximum yield. Too high yields have diluted flavours and low levels of sugars.
Harvest - early ripening harvest low levels of sugar, high levels of acid, less ripe flavours. Harvested later and high sugar, low levels acid and riper flavours. Grapes left on the vine start to shrivel, concentrated grape sugar
Can be harvested by hand or machine. Neither is better.
What is a GI?
Geographical Indicator - a legally defined vineyard area
Can be very large covering an entire region or in some instances an entire country
Or they can be very small and be no more than a single vineyard
