Winemaking - MA Questions 28.07.20 Flashcards
(40 cards)
Name two researchers who simultaneously isolated the first malolactic bacteria culture in the 50s.
Émile Peynaud in France and Brad Webb in California.
Name the main sugars found in grapes.
Glucose and fructose.
Aproximately how many grams of sugar would be need to obtain 1% alcohol?
Approx 17 grams.
Name two acids formed during fermentation.
Lactic and acetic.
Would a wine with a low PH require more or less SO2 for microbial stability ?
Less.
What is the difference between condensed and hydrolysable tannins ?
Condensed tannins are polymers of flavonoids that are extracted from grapes. The term tannin, used generally, refers to these. Hydrolysable tannins are derived from oak and comprised of non-flavonoids.
Define Anthocyanins.
A family of pigmented compounds responsible for the vibrant color of young red wine. They are found in the skins of the grapes.
Name the polyphenols that are largely responsible for bitterness in wine.
Catechins, mainly present in seeds and stems.
Which compound is responsible for bell pepper like flavours in Cabernet Sauvignon ?
Methoxypirazines.
Which enzyme produced by botrytis is responsible for rapid oxidation ?
Laccase.
Which esters are responsible for strawberry, kirsch, banana and bubblegum like flavours in wines made using Carbonic Maceration ?
Ethyl cinnamate and isoamyl acetate.
What is flash detente ?
A technique similar to thermovinification that accelerate the extraction of red grapes by exposing them to very high heat for a short period of time. Useful for creating an acceptable product out of low-quality or compromised fruit.
What is débourbage ?
Settling of the must followed by racking.
Explain flotation.
A method of clarification, in which gas is pulsed through the juice, and the solids float to the top of the liquid. The solids may be skimmed off or the tank may be drained, leaving the solids behind.
What is the difference between pumping over (remontage) and delestage ?
During pumping over the liquid is pumped from the bottom of the tank over the skins floating at the top. For delestage (rack and return), once a day, the entire volume of the liquid in the fermenting vat is drained off into a second vat and then is returned to the original vat by spraying it over the skins.
Name one region where the submerged cap fermentation is used for a greater extraction.
Piedmont.
Name two European oak species.
Quercus robur and Quercus petraea (or Quercus sessilis).
What is Ouillage ?
Topping every two weeks to replace the volume of wine lost to the atmosphere.
Which enzyme can be added to a finished wine to prevent malolactic fermentation ?
Lysozyme, derived from egg whites. It will not protect against yeast or acetic acid bacteria.
Which fining agent can be used to remove yeast including Brettanomyces ?
Chitosan, derived from the exoskeleton of crustaceans.
What is selection massale ? .
The selection of budwood for replanting from a number of vines throughout the vineyard, rather than single clones resulting in a broader genetic diversity
Which species of Vitis are mainly used for rootstock ?
Vitis Riparia, Vitis Berlandieri and Vitis Rupestris.
How is the Gobelet system known in Italy and Spain ?
Albarello and en vaso.
Which training style is preffered for Pinot Noir in Champagne ?
Cordon de Royat.
