The Humble Wine Grape… So what’s the story?
WHITE OR RED GRAPES
WHITE OR RED GRAPES RED GRAPES
Inside the grape the juice is clear… The colour comes from the skin!
…over 10000 grapes types
Vitis Vinifera
1
= 600 – 800 grapes or 10 Clusters 1 Ton of grapes = 720
720
= 7200 Clusters
Parts of a Grape
Stalk •
tannins
Skin • • •
colour tannins flavours
Seed •
bitter oil
Pulp • • •
water sugar acids
Waxy Coating •
Yeast (fermentation)
Pulp • Pulp is mostly made up of water and Sugar. The Sugar is needed by the Yeast which lies on the skin of the grape. It eats the sugar which is called fermentation. • During the ripening process the Sugar level increase and the juice becomes a little denser. • This density is measured to control ripening of the grapes. • In the Pulp contains acids like Tartaric and Malic acid.
Acidity helps: • to balance the sugar and alcohol; • the wine freshness; • to bring out the fruit flavours; • it age.
“Tannins are naturally occurring chemical compounds in grapes that contribute colour and sensory properties to the wine. They react with proteins in your mouth to give a sense of astringency. There are six times more tannins in red wine than in white.”
The Basic Wine Handbook
Tannins help: • with the taste; • the wine bitterness and fullness; • a wine age.
The flavour compounds that you find in the skin and in the pulp are very unique to each grape variety. They are primarily responsible the aromatic qualities in the wine.
Perfect Wine
Fruit
HARMONY & BALANCE Acidity
Tannins
So where can you grow these wine grapes?
Cooler climates where acidity is higher gives: • Lighter; • Crisper; • Less intense wines. Warmer climates where acidity is lower gives: • Rounder; • Fatter; • More intense wines.
Certain grapes ripen at different times, so picking the grapes is a very tricky and skillful job.
Macroclimate – large geographic area Microclimate – small geographic area
Things to remember: • Sunshine
• Rainfall
• Heat
• Wind
• Frost
• Soil
Sunshine • Minimum – 1500 hours of sunshine; • Red grapes need more sun than white grapes; • Cooler climate areas are not known for quality reds - Alsace, Germany as examples.
Heat • If the average temperature during the grown season is not at around 15 degree - the vine won’t produce; • If the temperature is too high – the vine will shut down; • If the temperature is too low – it will kill the vine; • Rivers, lakes and oceans can help to moderate the temperature.
Frost • This is not good if it hits when the spring buds have appeared; • It can kill the harvest;
• There are several expensive ways to help reduce the effect of frost, but it is very hard to save the whole vineyard; • For every 330 feet above the sea level the temperature drops about 1 degree. It also adds a few more weeks on the ripening period.
Rainfall • Need a minimum of 28 inches of water during the growing season; • Rain in spring is more valuable that later in the season; • If the rain hits at the wrong time – it can burst the berries;
• If there is not enough rainfall, certain parts of the world are allowed to irrigate.
Wind • Keep grapes dry and free from disease; • Moderate the temperature.
Soil • Grapes like bad soil; • If soil is too fertile it encourages unwanted vegetative growth; • The more the grape has to work to find nutrients the stronger the wine; • Best soils are porous, drain well and have moderately acidic. They also good at retaining heat;
• Having the correct soil type can have a major influence in the quality and price of wine you produce; • There are many different soil types.
A Vine can produce tons of grapes; The more grapes on a vine, the less quality the grape will be; Less grape bunches on the vine, the more mineral and taste concentration in the grape.
The Vine
Harvest •
When grapes are picked it is called the Harvest;
•
The number of grapes harvested is called the Yield. Quality winemakers like to focus on Low Yields. This is done by cutting away bunches of grapes before they develop and is called the Green Harvest;
•
Viticulture is the word giving to the art of growing grapes.
•
In the northern hemisphere the harvest takes place from August – October;
•
In the southern hemisphere the harvest takes places from February –April.
•
Grapes are harvested when there is an optimum sugar developed in line with the acid levels.
•
Brix is a unit of measurement for sugar levels (e.g. 22 degree Brix is considered the ideal measure for a wine).
Picking • Pick too early and grapes are under ripe and tart; • Pick too late and grapes are over ripe, jammy and have no character; • Weather is the key. Rain at harvest dilutes the grape and can cause fungal disease; • Not enough sunshine means grapes don’t ripen to their potential; • Picking grapes by machine is fast and efficient; • Picking grapes by hand is slow, costly but increase the quality of the grapes picked.
The Wine Making Process 1. Harvested grapes are put into a crusher (destemmer); 2. Then the grapes are crushed into a pulp and the juice is called ‘Must’; 3. This Must is pumped into a press for white wines and a tank for red. (White wine Must is pressed immediately so there is colour extracted from the skins. Red wine Must is allowed steep on the grape skins for weeks. The winemaker can decide how long so he can determine the level of colour extracted. This is called ‘Maceration’); 4. Its important in the Press that the juice is not too squeezed otherwise the juice can become cloudy and astringent! 5. The best juice is called Free Run (This is the juice that runs off before the Pressing has started);
The Wine Making Process 6. The juice is then Fermented (Yeast eats the sugar in the grape, creation alcohol and Co2 given off); 7. Many white wines are fermented in a steel tank. Many reds are fermented in oak barrels. Fermentation can be done in a steel or wooden and even concreate tanks. Fermentation is temperature controlled; 8. If temperatures are too low it will not spark of the yeast to start eating the sugars, too high - it can stop the fermentation; 9. When Fermentation is complete – the wine is Racked (moved) to an another vessel to mature. Racking removes, solids, less (dead yeast cells) that are at the bottom of the tank; 10. When the wine is finished it can either be bottled or laid to rest for 6 months up to a number of years to age and mature.
Oak barrels are usually used to mature the wine. This all adds to the cost of wine. Barrels are costly and are only used for a couple of years. Usually French or American oak is used – it helps the wine to develop different favours and can add to the complexity of the wine.
Glass bottles have been round since the Phoenicians. Nowadays in certain parts of Europe different regions have to use certain shape bottles (Mosel, Bordeaux, Burgundy, Champagne etc.). It takes about the 200 - 300 grapes to make one 750 ml bottle. Bottle Sizes: A lot of the sizes where names after Biblical Kings: Magnum 1,500ml – 2 bottles Jeroboam 3,000ml – 4 bottles Rehoboam 4,500ml -6 bottles Methuselah 6,000ml – 8 bottles Salmanazar 9,000ml – 12 bottles Balthazar 12,000ml – 16 bottles Nebuchadnezzar 15,000ml – 20 bottles.
Some clarifying agents may be used to speed up the process, such as egg white, fish bone, bulls blood. It is only used in parts per million. Vegan friendly wines are very fashionable so now more natural agents are being used.