WSET PART 2 Flashcards
What is sustainable viticulture?
-Man made chemicals are not prohibited, but use restricted
-Integrated pest management
What is organic agriculture?
-Only a very limited number of the more traditional treatments against pests and disease is allowed and only in small quantities
-Accreditation is required from an organic certification body if the producer wishes to display the organic credentials of their grapes on the label
What is biodynamic agriculture?
-Adopts organic practices, also incorporates philosophy and cosmology
-Vineyard soil seen as part of a connected system with planet earth, air, other planets
-Preparations are used to fertilize the soil and treat diseases, ward off pests
What is machine harvesting?
-Shakes trunk of vine and collects ripe berries as they fall off, leaving stalks behind
-Good for speed
-Can work through the night
-Only on flat or gentle slopes and for grapes not easily damaged
*Cant be used to pick grapes for wine styles that require whole bunches
What is hand harvesting?
-Pickers cutting off individual bunches of grapes with secateurs
-Slower/expensive
-Allows for grape selection
-Essential for noble rot
-Less damage
-Grape stems are retained
-Good for steep vineyards/slopes
Seeds/Stems?
- Both contain tannins
-Seed have high levels of bitter oils
-Stem only available if hand harvested
Skins?
-High flavor compounds which gives grapes varietal character
-Tannins/color compounds
Tannins?
-Before veraison- Very bitter/astringent, but will fall as grapes ripen
Pulp?
-Water is largest component in grapes pulp
-Sugar is the 2nd largest, yeast uses it to make alcohol
-Acids also found in pulp
(Tartaric is most abundant, followed by malic)
What is used to keep oxygen in wine to a minimum?
-Antioxidants such as sulfur dioxide
-Picking grapes at night, effects of oxygen reduced because chemical reactions occur more slowly at lower temperatures
What is sulfur dioxide?
-Antioxidant + Antiseptic
What does SO2 do?
Protects the grape juice and wine from the effects of oxidation
What is the level of toasting?
-The temperature and length of heat exposure
-It affects what flavors the barrel contributes to the wine
What are inert winery vessels?
-Used for fermentation
-Can be used to temporarily store finished wine
-Most made of stainless steel or concrete
-Do not add flavor to wines or allow oxidation
What is must weight?
Level of sugar in the juice
When does pressing take place for whites?
Reds?
Whites- Before fermentation
Reds-After fermentation
What is RCGM
Rectified concentrated grape must- Colorless, odorless syrupy liquid
-Helps raise alcohol in wine
-More sugar available for yeast to turn to alcohol
What is alcoholic fermentation?
Conversion of sugar into alcohol and CO2 through the action of yeast
If winemaker wants to stop fermentation before all sugar has been converted?
Can kill or remove yeast by adding SO2 or adding grape spirit
What are other by products of alcoholic fermentation?
Heat and flavor compounds
2 ways to control fermentation?
Yeast and temperature management
What do ambient yeasts do?
-Increase complex flavors in final wine, but can’t control which yeasts are present
-Can also have variation between batches
What are cultured yeasts?
-Individual strains of S. Cerevisiae which consistently perform and produce attractive flavors
-They limit potential complexity of wine
What do lower temperatures do for wine?
Avoid loss of the most volatile aromas which often have a floral character
-Can encourage development of fruity flavors in whites
What do higher temps do to a wine?
-Too high, can kill yeast
-Needed for extraction of color and tannin from black grape skins
What is Malolactic fermentation?
-Takes place once alcoholic fermentation has finished and is carried out by lactic acid bacteria
-Covert tart malic acid into softer lactic acid
-Softens and reduces acidity, creates buttery flavors and produces CO2
How to avoid MF?
Storage at cool temperatures, the use of SO2, filtering out bacteria
Dead yeast cells that fall to the bottom in a few hours?
Gross lees
Smaller particles that settle slower?
Fine lees
Main alcohol in wine?
Ethanol
Most abundant component in wine?
Water
3 acids?
Tartaric, Malic, Lactic
What is blending?
-Improves balance, attains consistency, achieves a certain style
-Usually carried out after fermentation or during maturation