Aging Flashcards
What are yeasts?
Yeasts are microscopic single-celled fungi that reproduce by budding or sporulation and produce enzymes that trigger the fermentation of sugars, thereby creating various compounds. including alcohol.
What is the dominant yeast during fermentation.
Saccharomyces cerevisiae
What is the chemical equation of alcoholic fermentation?
one molecule of sugar (glucose/ fructose) is converted into two molecules of ethanol and two molecules of carbon dioxide, as shown in the formula.
C6H12O6 → 2C2H5OH + 2CO2.
What are the considerations for the use of commercial yeast?
It is more widely used, requires hydration, quick and easy to prepare, allows for a lower consumption of yeast (and so is more economical), less exclusive. **
What are the considerations for the use of selected yeast?
The preparation process is a lengthy one, a technique of progressive volumes is used, confer exclusivity, requires a higher level of staff training, give the resulting wine more personality. **
Are selected yeasts also Saccharomyces cerevisiae?
Yes, there are thousands of different selected (indigenous) and commercial strains of Saccharomyces cerevisiae.
Why is Saccharomyces cerevisiae the most predominant yeast in wine fermentation?
high resistance to the presence of alcohol and carbon dioxide. **
What is the etymology of Saccharomyces cerevisiae?
sugar, fungus, beer
What are examples of the “tertiary aromas” in Cava?
dried fruits, nuts, baking bread **
What process allows the bubbles of Cava to be created?
The producer must add the tirage liqueur.
What is tirage liqueur?
a mixture of base wine, sugar (sucrose, concentrated grape must, rectified concentrated grape must or partially fermented grape must) and yeast
How is carbon dioxide generated in Cava?
Yeasts generate carbon dioxide gas in a natural and endogenous way.
What is autolysis?
Once the fermentation of the yeast is complete, it gradually dies inside the bottle and begins to break down creating proteins that are integrated into the wine. More technically, a biological process by which a cell destroys itself. [Apoptosis is intentional programmed cell death whereas autolysis is unintentional digestion of the cell from within.]
What are lees?
the remains of the yeast
What is the relationship between autolysis and the wine’s aromas?
During autolysis, amino acids are released and volatile compounds are formed that contribute to the wine’s aroma (esters, higher alcohols); referred to as “tertiary aromas.”
