Biological Ageing Flashcards
To what alcohol level wines are fortified for biological ageing?
to between 15% and 15.5%.
Why is wine fortified to 15%/15.5% in biological ageing?
This is the ideal strength for the development of flor
Why is a second classification is important in biological ageing?
Because the producers need to see if the flor develops correctly on these wines and whether it has a style and character that is suitable for its respective solera system.
What will happen to the wines that fail to make the grade suitable for solera system?
Wines that fail to make the grade are either refortified and sent for oxidative ageing or rejected altogether.
What does biological ageing require?
the presence of flor
What is flor made up of?
a number of yeast strains
What does flor do?
The yeast strains form a thick layer on the surface of the wine. They feed off the alcohol (and other nutrients) in the wine and oxygen in the atmosphere to produce carbon dioxide and acetaldehyde.
What is acetaldehyde?
Produced by the flor, it is the acetaldehyde that that gives biological aged Sherries their unique flavour.
What does flor need to thrive?
On order to thrive, flor needs precise levels of alcohol, temperature and humidity.
How does flor sensitivity to the ambient conditions affect the final Sherry?
Flor’s sensitivity to the ambient conditions is such that the temperature and humidity of an individual bodega and even a butt’s position within it can influence the style of the maturing Sherry.
What is the maximum abv that flor can tolerate?
Flor cannot thrive in a wine with an abv above 15.5%
What is an ideal condition for flor to thrive?
Flor favours cool to moderate temperatures and high levels of humidity.
Describe the lifecycle of flor
Flor grows more vigorously in the spring and autumn and dies back in winter and summer.
Why is topping up the butts important?
The flor is constantly consuming alcohol and other nutrients and therefore regular additions of new wine is needed to keep the flor supplied with these nutrients. In order to maintain a ready flow of nutrients between the criaderas, wine is drawn off the solera at frequent and regular periods throughout the year. This affects the style of wine as well.
Is it possible to keep the flor culture alive indefinitely?
yes, but wine taken from these solera systems rarely has an average age greater than 3 to 4 years. As the average age of the wine increases the overall level of nutrients in the oldest criadera and solera drops and by the time the average age reaches 7 years the levels are sufficiently low that the flor can start to fail and oxidative characteristics develop.
