Vinification Flashcards
*What creates volatile acidity in wine?
Acetaldehyde converts to Acedic acid which the alcohol and creates volatile acidity.
Acetaldehyde - Aceidic Acid - Volatile Acidity.
*What causes Volatile Acidity to be a fault in wine?
- excessive acetic acid has been produced by the acetobacter (bacteria responsible for turning wine to vinegar) in the presence of oxygen.
- Yeasts require nitrogen to work, and low levels of nitrogen in the must leads to the formation of hydrogen sulfide (H2S), a highly volatile compound reminiscent of rotten eggs.
- H2S levels may also be affected by the addition of SO2
- access acetic acid and oxygen
In degrees, what temperature does Yeast live?
50°F to activate
113°F dies
(50F-113F)
*Give two examples of wild yeast?
Kloeckera
Candida genera
*What is Ambient Yeast?
naturally occurring in the winery not the vineyard
Name 2 méthodes for reducing (removing) alcohol form wine/
Spinning Cones
Reverse Osmosis
What are the stages of reverse osmosis?
Permeate - water / alcohol -distilled/added to retentate
Retentate - wines aromatic compounds
What is the difference between ‘Pigage’, ‘Remontage’ and ‘Delestage’?
Pigeage - punching down
Remontage - pumping over
Delestage - drain whole tank. Refill
What is the difference between Vin de Goutte and Vin de Presse?
Vin de Goutte - free run (high quality)
Vin de Presse - pressed wine at the end
What is Soutriage?
‘Racking’ movement of wine from its barrel, to a clean barrel.
Define collage.
‘Fining’ of a wine
What is debourbage?
(white wine making)
- stage where the juice settles
At what temperature do tartrate crystals precipitate out of the wine?
(during cold stabilization)
- around 25F degrees
To produce rose, blending is prohibited in the EU for what wines?
Wines below PGI level.
What is the difference between ‘Maceration’ and ‘Saignee’ in the production of Rose wine?
- Maceration :
- leaving juice in contact with skins to extract color.
- Saignee :
- intentional by product of red wine making.