Common element in Winemaking Flashcards
COMMON ELEMENT - Grape constituent
Stem/stalks: tannins
Skin: colour, tannin, flavour
Bloom (waxy surface): natural yeast
Pulp or flesh: water, sugar, acid
Seeds: tannins, bitter oil
COMMON ELEMENT - Oxygen
in winemaking: a fruit driven wine will reduce the contact with oxygen (anaerobic winemaking) by adding carbon dioxide in winery and piking the grapes at night.
in maturation:
- fruit driven wines will continue to mature in stainless steel, completely full (No oxygen)
- wine matured aerobically are store in oak. this helps soften the tannins and gives more complexity to the flavour.
COMMON ELEMENT - Sulfur Dioxide SO2
It act as an antioxidant and an antiseptic, protects freshly harvested grapes from bacteria.
GRAPE PROCESSING - grape reception
Grapes is checked to eliminate unripe or rotten grape
GRAPE PROCESSING - Destemming and crushing
Are both optional process.
Crushing should not involve the seeds as they are quite bitter
Crushing means that the grape juice and skins would already start to macerate. Cold maceration extract more flavour and colour.
GRAPE PROCESSING - Pressing
Separates liquid from solid.
Wine presses are vertical baskets or
Pneumatic presses (rubber horizontal tube, stainless steel cylinder) closed tank (no oxygen)
Sugar and Alcohol
Rectified Concentrated Grape Must can be added in cooler climates condition where sugar may be insufficient.
This will also increase the level of alcohol in the final wine because there is more sugar available for the yeast to turn to alcohol.
Sugar can be also added from sugar beets, a process called chaptalisation.
Another option is to remove water from the juice, which concentrate the sugar and can lead to a wine that is higher in alcohol
Acidification
Add tartaric acid in powder form.
Deacidification
add alkali (chemical opposite of an acid)
FERMENTATION - Alcoholic fermentation
Converts sugar in alcohol and CO2, trough the action of yeast
Yeast
There are ambient yeast and cultured yeast (can be add to the must)
Temperature
Lower temperature for white wines avoid the loss of aromas and floral characteristics.
Higher temperatures are necessary for the extraction of colour and tannins from black grape skins.
Excess heat can be prevent by pumping over, punching down
Malolactic fermentation MLF
Once the alcoholic fermentation has finished, this fermentation is carried out by lactic acid bacteria.
They convert the tart malic acid into softer lactic acid.
it may be encouraged by raising the temperature of the wine and by not adding SO2 after the alcoholic fermentation.
MLF reduces acidity, creates a buttery flavour and creamy texture.
PRE BOTTLING MATURATION AND BLENDING - Lees
After fermentation, dead yeast cells fall at the bottom of the fermentation vessel. White wine can be kept in contact with lees during pre-bottling maturation in order to add extra flavour and richer texture.
Pre bottling maturation
To survive maturation a wine needs sufficient level of tannins, acidity and or alcohol, and they must have flavour that will develop in an interesting way.
Primary fruit aroma are retain by bottling the wine after just few months.
the maturation affect flavour by adding oak flavour or by allowing oxidation to take place
Blending
It can be use to improve balance and consistency