Winemaking And Maturation Flashcards
What part does oxygen play in the making of wines that are dominated by primary flavours?
No part, oxygen is detrimental to primary fruit flavours and the winemaking will try to avoid the grapes making contact with oxygen
What four ways can a winemaker prevent grapes getting into contact with oxygen?
Using antioxidants such as sulphur dioxide
Picking grapes at night when temps are lower as chemical reactions happen slower at lower temps
Keeping grapes chilled until they reach the winery
Airtight tanks are filled with Carbon dioxide or nitrogen to keep oxygen out
What is the method called when wine is limited to oxygen contact?
Anaerobic or protective winemaking
Do wines that have been protected from oxygen during winemaking ever benefit from oxygen during maturation?
No wines that have been protected from oxygen in the winemaking process. Wines made to have primary flavours dominate should be matured in stainless steel vats or concrete inert tanks
Are oak barrels airtight?
No they are not airtight they allow small amounts of oxygen into the barrel which then reacts with the wine altering the flavours
What benefits does allowing small amounts of oxygen into the barrel and reacting with the wine?
Softens tannins in red wines
Adds further complexity of flavour as primary flavours fade and tertiary flavours develop
Colour changes to more of a brown in reds and orange in whites
Which size oak vessel offer more oxidation to the wine?
Smaller vessels such as 225 litre oak barriques as they offer a proportionately large surface area of wood to wine
How long can wines be kept in oak barriques for?
2 years max as the oxidation levels will be too high
Is there an exception where wine is kept in 225 litre oak barriques for longer than two years?
Yes in fortified wines such as Olorosso Sherry, tawny port and rutherglen muscat which is deliberately oxidised
What flavours do fortified wines which have been oxidised produce?
Pronounced flavours of caramel, nuts and toffee
What process happens when the grapes reach the winery?
This is grape reception. This is where the grapes are given their first dose of SO2.
For premium wines, grapes are individually sorted.
For high volume wines, this isn’t possible
Is destemming and crushing mandatory?
Both aren’t optional, as grapes arrive at the winery without stems if they are machine harvested.
What does crushing achieve?
Crushing is where a machine or somebody standing on the grapes breaks the skins and liberates a quantity of juice. This is free run juice
Should the seed be crushed?
No the seed should not be crushed as it will release bitter oils into the wine
What is pressing?
This is when liquid from the grape and solid constituents are separated.
What is the difference in the pressing process when making white and red wines?
White wines should be pressed before fermentation
Reds will be pressed after fermentation so that the wines can extract tannins and colour from the skin
What is grape juice commonly referred as?
Must
In cooler climates, there may be insufficient natural sugar to give the wine a satisfactory alcohol level. How can a winemaker increase sugar levels?
The winemaker can add RCGM (rectified concentrated grape must) which is colourless, odourless syrup like liquid
When can RCGM be added?
Either before or during fermentation
What is the process called when RCGM is added to a wine to increase sugar levels?
Enrichment
How does enrichment increase alcohol levels in the wine?
The presences of extra sugar in the wine before fermentation allows the yeast to convert sugar to alcohol
Enrichment is forbidden in many countries. Why?
Because it can produce a wine that tastes hard and thin and there are insufficient flavours to balance the artificially elevated alcohol
What is chapitalisation?
Where sugar from sources other than grapes is added, such as sugar beet
Winemakers can remove water from wines which can concentrate flavours. But what are the downsides of this?
They concentrate other compounds such as tannin and acidity
