General Vinification for Sparkling Wine Flashcards
(147 cards)
In what style of sparkling wine is whole bunch pressing preferred?
-traditional method premium champagne
What is the advantage of whole bunch pressing?
- it is gentle and therefore less extraction of phenolics (tannin and anthocyanin) and solids
- stems act as a drainage channel for juices to run thus minimising pressure needed in the press
What is the disadvantage of whole bunch pressing?
Which presses are commonly used in whole bunch pressing?
- basket presses and pneumatic presses
Give a disadvantage to the basket press
-less juice extracted in order to avoid risk of extracting low molecular weight solids from the seeds
What effect in terms of sensation does low molecular weight phenolics contribute?
-bitterness and coarse mouthfeel
What is the priority in pressing black grapes for sparkling wine?
-speed to decrease maceration and extraction from skins
-
What are press fractions?
-parts of the pressed juice differentiated by the pressure at which they were pressed from the grapes
(extra info: the first press fraction has the intermediate zone of the pulp , the next is the central zone close to the seeds and the last is the primary zone next to the skin - hardest to press as attached to skin so releases the most phenolics from the skin)
What is free run juice?
-the 60-70% of juice which runs out of the grape when it is crushed (ie. split)
Which has highest phenolics, free run or press juice?
Press juice is highest in phenolics
Why separate press fractions?
For Blending Options
For SHORT MATURATION wine for early consumption, what is the dominant juice?
-Press Juice as it is faster maturing
Are all solids removed before fermentation and why?
-no, they aren’ because some solid is required for both primary and secondary fermentation
What process happens between pressing and first fermentation ?
Clarification
What can be used to removed excessive tannin or color before fermentation?
- casein
- PPV (powdered plastic removing browning and astringency) from
- gelatin (fining agents)
What is used to remove larger solids from the grape must?
- racking to removed the juice from settled sediment
- centrifugation
- flotation using an inert gas
Why is it a good idea to chill your juice during clarification?
To avoid oxidation
At what temperature range does the first fermentation take place?
14oC to 20oC
What fermentation vessel is usually used in first fermentation?
stainless steel
why is the principle vessel used for 1st fermentation
temperature control
Easy cleaning
Large format
what does the temperature of the 1st fermentation encourage?
- maintenance of the delicate primary flavors
- yeast activity
What is a low pH environment like for yeast?
-stressful
What must a winemaker consider when selecting yeast strain?
- if it can remain active in low pH and alcoholic high stress environments in the ferments
- if it promotes aromatics like thiols and esters (good for fruity non-autolytic wines)
Is it common to use the same yeast for first and second fermentation?
yes. The yeast same yeast is usually used for both