Vinification Flashcards
The transformation of grape juice into wine
What is Vinification
The transformation of grape juice into wine
What is Alcoholic Fermentation
The metabolism of yeast cells converts sugars grape must into ethyl alcohol (ethanol) and carbon dioxide (CO2). Heat is generated during the process.
What is Grape Must
Must is freshly crushed fruit juice that contains the skins, seeds, and stems of the fruit.
Why is additional Sulfur dioxide added?
Additional sulfur dioxide is added to the fermenting Must or Juice beforehand to prevent oxidation and bacterial contamination, and to ensure rapid fermentation
Below 50 degrees, most yeast will ___.
Above 113 degrees, most yeast will ___.
below 50, Most yeast will not act.
above 113, most will die.
White wine fermentation are on the Cooler or Hotter side of fermentation?
Cooler to preserve fruit and freshness
Red wine fermentation are on the Cooler or Hotter side of fermentation?
Red wine is fermented on hotter scale of fermentation to increased the extraction of color, tannin and flavor compounds.
What is stuck fermentation?
A sudden shut down of yeast activity
define : Autolysis
A chemical reaction between the wine and the lees by which enzymes break down the dead yeast cells, producing amino acids and releasing proteins and carbohydrates into the wine. It imparts characteristics in a wine such as richness and creaminess as well as aromas of bread dough, toast or brioche. It is a key element of the traditional method of making sparkling wine, such as Champagne.
What is Lees Contact?
Lees, also known as Sediment, are leftover yeast particles from autolysis which is the self-destruction of yeast cells by enzymes created from fermentation. As strange as this may seem, lees are used in white and sparkling wines to add beneficial textures and flavors.
the dead yeast cells leftover from fermentation, can enhance an aging wine with added richness, flavor and aroma complexity, and can also bind with excess tannins.
What is Batonnage?
French term for stirring the lees during the aging and maturation of wine.
What are the two types of yeast?
Cultured (controlled) yeast and Ambient (Wild) Yeast.
What is reverse osmosis?
it separates the wine into two parts (Permeate - Water and Ethanol) and Retentate (wines aromatic compounds) allowing adjustments to alcohol level before recombining.
What is Acidification?
The addition of acid to must or to a finished wine.
What is tartaric acid?
The principal acid in grapes and wine; contributes to taste and stabilizes color. Unlike malic acid, tartaric acid does not decline as grapes ripen. Tartaric acid can precipitate out of solution in bottled wine to form harmless tartrate crystals resembling shards of glass.
What is Malic Acid?
A sharp, tart acid found in grapes as well as in green apples. Less-ripe grapes or grapes grown in cooler climates can contain high levels of malic acid; the resulting wines often contain aromas and flavors reminiscent of green apples. It is converted to smoother lactic acid during malolactic fermentation.
What is Malolactic Fermentation?
Also known as Secondary Fermentation, lactic acid bacteria converts harsh malic acids into softer lactic acids and carbon dioxide. it rounds out a wine texture.
What is Diacetyl?
The compound responsible for buttery aromas in wine, is a byproduct of malolactic fermentation.
What is Carbonic Maceration (Maceration Carbonique)?
Carbonic maceration is the process that occurs when intact bunches of red grapes are fermented in a sealed vessel that has first been filled with carbon dioxide.
Long version of Carbonic maceration
Whole bunches of grapes are placed in vats, which are then sealed and filled with CO2 to remove the oxygen.
This triggers a process within the grapes known as intracellular fermentation. Once alcohol levels reach around 2% abv, the grape skins split and release their juice.
Carbonic maceration extracts some colour from the grapes but little tannin, generally creating red wines that are light in colour, low in tannin and which have a soft, fruity wines character.
Wines made in this style include Beaujolais Nouveau and are often best when drunk young and sometimes even lightly chilled.
Read more at https://www.decanter.com/learn/advice/carbonic-maceration-54082/#Ji8adME2GHCqJhMO.99
