Common element in Winemaking

Question 1

COMMON ELEMENT - Grape constituent

Answer 1

Stem/stalks: tannins

Skin: colour, tannin, flavour

Bloom (waxy surface): natural yeast

Pulp or flesh: water, sugar, acid

Seeds: tannins, bitter oil

Question 2

COMMON ELEMENT - Oxygen

Answer 2

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.

Question 3

COMMON ELEMENT - Sulfur Dioxide SO2

Answer 3

It act as an antioxidant and an antiseptic, protects freshly harvested grapes from bacteria.

Question 4

GRAPE PROCESSING - grape reception

Answer 4

Grapes is checked to eliminate unripe or rotten grape

Question 5

GRAPE PROCESSING - Destemming and crushing

Answer 5

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.

Question 6

GRAPE PROCESSING - Pressing

Answer 6

Separates liquid from solid.
Wine presses are vertical baskets or
Pneumatic presses (rubber horizontal tube, stainless steel cylinder) closed tank (no oxygen)

Question 7

Sugar and Alcohol

Answer 7

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

Question 8

Acidification

Answer 8

Add tartaric acid in powder form.

Deacidification
add alkali (chemical opposite of an acid)

Question 9

FERMENTATION - Alcoholic fermentation

Answer 9

Converts sugar in alcohol and CO2, trough the action of yeast

Question 10

Yeast

Answer 10

There are ambient yeast and cultured yeast (can be add to the must)

Question 11

Temperature

Answer 11

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

Question 12

Malolactic fermentation MLF

Answer 12

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.

Question 13

PRE BOTTLING MATURATION AND BLENDING - Lees

Answer 13

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.

Question 14

Pre bottling maturation

Answer 14

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

Question 15

Blending

Answer 15

It can be use to improve balance and consistency

Question 16

Balance

Answer 16

Free run wine may be blended with press wine to increase the tannins in the final product

Question 17

CLARIFICATION - Sedimentation

Answer 17

Racking process - The wine can be pumped into a different vessel leaving the sediment behind

Question 18

Fining

Answer 18

Hazes or deposit are removed by adding a fining agent.
The clumps formed will then be removed by filtering

Question 19

Filtration

Answer 19

Depth filtration - The filters are made of thick layer of material
Surface filtration - Very fine sieves are used

Question 20

STABILISATION

Answer 20

Tartrate stability - Tartaric acid appear as crystals, harmless and flavorless. Can formed with cool temperature during the maturation process.
Removed with filtration

Microbiological stability - Different forms of bacteria and yeast can spoil a wine.
Clean materials are the key

Oxigen stability - In excess, oxygen can oxidise the wine.
It can be minimise by adding SO2.

Question 21

PACKAGING

Answer 21

Cork - it allows small amount of oxygen to gradually enter the bottle, helps develop tertiary aromas.

Synthetic cork - Made from plastic, made for early drinking wines

Screw caps - They don’t taint the wine, preserve the fruit flavour.

Question 22

Post bottling maturation

Answer 22

Any ageing should be in cool dark place (10-15C) , lying on the side so that the cork remain moist.