1. What is Wine? Flashcards
What is wine?
What does alcoholic fermentation require?
By products of fermentation?
Wine is fermented grape juice.
The grapes are crushed to release their juice. Alcoholic fermentation is needed to change the grape juice to wine.
Yeast and Sugar
Alcohol and Carbon dioxide
Skin and Pulp
Parts of a Grape
Tannins come from Black grape skin
Two principal types of grapes:
white and black grapes.
On the inside, the grapes look similar
* Grape skins are the key difference:
Black grapes have deeply coloured skins that contain tannins.
White grapes have a golden colour.
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Pulp
It is soft and fleshy.
The colour of the pulp is the same regardless of the colour of the grape skin.
Contains grape juice, which is made up of:
water, sugar and acid.
Tannins make your mouth feel dry.
Alcoholic Fermentation
The fermentation process
How is the level of alcohol in wine measured?
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Alcoholic fermentation requires yeast
Yeast are microscopic organisms that eat sugar and convert it into alcohol and carbon dioxide gas. - This process continues until the yeast have eaten all the sugar. The alcohol stays in the newly made wine and in most cases the carbon dioxide escape into the atmosphere.
sugar + yeast —- fermentation—-> alcohol + carbon dioxide
alcohol by volume (abv): i.e. 10% abv means that 10% of the liquid is alcohol
Growing Grapes
How Grapes Grow
What is flowering?
- Every year a grape vine flowers in the spring
- Flowers become grapes which ripen in the summer
- The grapes are picked in the late summer
- Each flower will become a grape
When a cluster of grapes vines flowers
What happens when grapes ripen?
- The grapes swell with water
- Sugar levels in the grapes rise
- Acid levels in the grapes fall
- Flavours become riper
- White grapes change from green to golden
- Black grapes change from black to purple
Where do grapes grow?
To grown and produce good quality fruit, grape vines need sunlight, heat and water
* the right levels of sunlight and heat to grow
* winters that are cold enough for them to rest
Climate can have a defining impact on the characteristics of the grapes
Where Grapes Grow
Cool Climate Regions
+30 to 60 degrees north of the Equator
Germany, northern France
- Regions with cool climates are closer to the poles
- E.g. Germany and northern France
- Average temps. are low and sunlight weaker in regions near the Equator
- In some years, grapes can struggle to ripen
- In cool climate regions it is common to grow white grapes
Colder climate = lower levels of sugar + high levels of acidity
Where Grapes Grow
Warm Climate Regions
-30 to -60 degrees south of the Equator
Parts of Australia, of South Africa and of California
- Regions with warm climates are closer to the Equator
- E.g. Parts of Australia and parts of California
- Average temps. are high, sunlight is more intense, and grapes ripen consistently
- In warm climate regions it is common to grow black grapes
Warmer climate = higher levels of sugar + lower levels of acidity
Grapes’ flavours taste riper in warmer climates!
Making White Wines
How are white wines made?
Describe the process
Black grapes are gently pressed before fermentation…
- Crushing: White grapes are crushed after picking. This releases some of the grape juice
- Pressing: The crushed graoes are pressed to release the remaining juice
- Fermentation: Yeast are added to the grape juice and some of the fermentation starts. In stainless steel tanks or oak barrels
- Maturation: Once fermentation has finished, the wine can be stored in stainless steel tanks or in oak barrels
- Bottling: The wine is transferred to bottles
Black grapes can be used to make white wines.
Black skins= Clear juice
…this can give juice suitable for white wine production.
Making Red and Rosé Wines
How are red wines made?
Describe the process for red and rosé wines
For Rosé Wines: See ‘Draining in footnotes.
- Crushing: Red grapes are crushed after picking. Grape skins and juice are put into the fermentation vessel.
- Fermentation: Yeast are added to the grape juice and skins, and fermentation starts. Colour and tannins are extracted from the skins by mixing them thoroughly with the juice.
- Draining: Once fermentation is finished, the newly made wine is drained off the skins
- Pressing: The grape skins are pressed to release remaining wine.
- Maturation: Wines can be stored in stainless steel tanks or oak barrels.
- Bottling: The wine is transferred to bottles.
Crushing > Fermentation > Draining > Maturation > Bottling
Rosé wines
Draining: The juice is drained from the skins after a few hours. It is pink in colour. It finishes fermentation without the skins.
Types of Wine
Types of Wine
Still, Sparkling and Fortified wines
There are three types of wine:
Types of wine are NOT the same as Styles of wine!
STILL WINES
- The majority of wines fall in to this category.
- They are still and between 8% and 15% abv. The majority are between 11.5% and 14% abv.
- Many still wines are named after the region in which they are produced. E.g. Sancerre and Burgundy from France; Rioja from Spain; and Chianti from Italy.
- Other wines are named after the grape variety used to make them. E.g. Pinot Grigio; Chardonnay.
Types of Wine
Types of Wine
Still, Sparkling and Fortified Wines
There are three types of wine:
SPARKLING WINES
- These are wines that are bubbly or fizzy
- The fizz is caused by the carbon dioxide gas produced by fermentation and trapped in the wine. When the wine is opened the gas escapes as bubbles in the wine.
- Examples include Champagne from France, Méthode Cap Classsique (MCC) from South Africa, Cava from Spain and Prosecco from Italy.
- Sparkling wines are made all over the world
Types of Wine
Types of Wine
Still, Sparkling and Fortified Wines
There are three types of wine.
FORTIFIED WINES
- These wines have extra alcohol added to them, therefore have higher levels of alcohol ranging from 15% to 22% abv.
- Examples include Sherry from Spain and Port from Portugal.
Styles of Wine
STYLES of Wine: White, Red and Rosé
All three types of wine can come in a variety of styles.
COLOUR of a wine can be determined by the grape variety used as well as the way the wine is made.
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WHITE wines are typically made using white grapes. Chablis (France) and Riesling (Germany).
Is it possible to make a white wine from black grapes.
The colour in black grapes come from the skins, therefore if skins are seperated from the juice before fermentation, a white wine can be made. - RED wines must be made using black grapes. The coloured grape skins stay with the grape juice during fermentation, bringing colour to the wine. Rioja and wine made from the Cabernet Sauvignon grape.
- ROSE wines are made from black grapes. The grape juice is left in contact with the grape juice for a short period before it is drained. The juice is only lightly coloured by the skins. E.g. White Zinfandel
The style : Colour, Structural characteristics, Aromas and flavours
