WHITE WINE VINIFICATION Flashcards
Why is there no SO2 added during transportation of grapes from vineyard to cellar?
SO2 will aid extraction. Not only from the skins, but also from seeds, stems and other stuff that might be in the harvest bin.
Which two options do you have to protect your freshly harvested grapes during transport (or waiting in the cellar to be processed)?
Dry ice
Sorbic Acid
Name 5 requirements for successful skinmaceration
Healthy and uniform grapes
Protected by CO2
8-20 hours maceration
Temperature around 13C
Crushed or destemmed grapes
Elaborate on grape pressing
Pneumatic press, without oxygen
Progressive pressure 0,5-2,5 bar
(optional) Addition of 50 g/l SO2
Temperature < 20C
What is a practical disadvantage of whole bunch pressing?
Less amount of grapes can fit in the press. Making the reception process longer
Name 2 advantages of whole bunchpressing
Limits oxidation
Binds proteins so more stable and less bentonite needed
Name 3 aims of clarification
Less turbidity
Decrease reduction odours
Decrease green aroma’s and bitterness
At what NTU level do you have risk on sluggish fermentation? What is a normal NTU rate?
Sluggish: Lower than 100 NTU
Normal: between 15/100-250 NTU
How much active dry yeast (ADY) do you need to inoculate a tank?
10-15 g/l or 10 to 6 cells/ml (often in prepared matter)
Name two measurements to prevent MLF
Lower temperature to 10-12C
Add SO2
Name 3 results of MLF
Lower AC
Better biological stability
Increased complexity
Why is neutral oak or light toasted oak never used on white wines?
The oak will release too much harsh tannins
What does SB / R / Manseg / Petite Arvine / M / CS have in common?
They are all susceptible for high production of volatile thiols
What compound, found mainly in the grape skin can protect from oxidation?
Anthocyanin
What fermentation temperature is producing the highest amount of volatile thiols?
20C
Describe in 3 terms an ideal growing season
Long
Moderate waterstress after veraison
Reaching full ripeness
Name 3 results of low N
Decreased aroma potential
Higher amount of phenolics
Less glutathione
Why does SB need more bentonite?
SB has naturally higher levels of protein
Which compounds are responsible for the ‘coffee’ aroma
H2S in combination with furfural
Resulting in furfurythiol
Does AF in oak increase or decrease oakiness in the final wine?
Decrease
What do SB and SEM each contribute to the blend?
SB: freshness and fruitiness
SEM: richness and texture
Which variety is mostly aged in barrel, SB or SEM?
SEM
Name 3 compounds that are released by lees ageing
Glutathione
Sulfur amino acids
Mannoproteins
