Quiz - Extraction to Maturation for Red Wines Flashcards
What are the solutions tannins and anthocyanins are most soluble in?
Tannins - More soluble in alcoholic solutions
Anthocyanins - More soluble in aqueous solutions
Which factors affect extraction of anthocyanins, tannins and flavors from the grape skins?
- Management of the skins and juice
- Temperature
- Time on skins
The following factors don’t affect the extraction:
1. Ageing on the lees
2. Exposure to SO2
Which wine component is the source of color in young red wines?
Anthocyanins
Which winemaking processes can help promote or reduce color stability in red wines?
The following promote color stability:
1. Micro-oxygenation
2. Barrel ageing
The following reduce color stability:
1. Addition of S02
2. Lees ageing
Which wine component found in the skins of black grapes make them less vulnerable to oxidation than white grapes
Phenolics
How long does pre-fermentation maceration (cold soaking) often last for red wine?
3 to 7 days
What are the two alternative terms for cold maceration?
Cold soaking and Pre-fermentation maceration
If a winemaker chooses to use flash détente or thermovinification when producing red wines, what quality levels of wine will they likely be aiming for?
Mid-level
What is the name of the oxidative enzyme produced by grey rot in botrytised grapes that the high temperatures used in flash détente and thermovinification can help denature?
Laccase
Match the various cap management techniques to their respective French names.
Punching down – Pigeage
Pumping over – Remontage
Rack and return – Delestage
Explain the key differences between carbonic maceration and semi-carbonic maceration fermentations. Think about the following when answering:
- What are the objectives of each form of fermentation?
- What flavor’s/aromas might be produced by each technique?
- What style of wine might a winemaker be aiming for with each technique?
- What are the cost implications for each technique?
Carbonic maceration is carried out on whole, intact bunches that are put into vessels and carbon dioxide to remove all oxygen. Intracellular fermentation begins and when the alcohol level in the grapes reaches 2%, the grapes split and release their juice. The juice is drained off and the skins pressed. Both components are blended back, and the fermentation continues off the skins.
The aromas/flavors associated with carbonic maceration are kirsch, banana, bubble gum (boiled sweets/confected) and cinnamon.
The style of wine is fruity with low tannin and for early consumption.
There are little cost implications with this technique and the wines are usually unoaked, so costs are minimal.
Semi-carbonic maceration varies slightly to carbonic maceration as the tank is not filled with carbon dioxide. The tank is filled with whole, intact bunches but it is the weight of the grapes that crush the berries at the bottom of the vessel, releasing juice. Cultured yeast can be added at this point, but it is traditionally ambient yeast. With this the fermentation starts, producing carbon dioxide, which is trapped in the vessel, the intact berries undergo intracellular fermentation. Once these berries split i.e. when they reach 2% alcohol, the juice is drained, and the grapes are pressed. Both components are blended back, and the fermentation continues off the skins.
For more complex styles of wines, the fermentation may continue on the skins to add the desired tannin, color and body to the wine. Cap management techniques will be used to extract the components from the grapes.
Depending on how much or little cap management is carried out, the wines will be more or slightly less fruit driven, displaying typical fruit flavors depending on the grape variety.
The style is like carbonic maceration but if there is more skin contact during fermentation and cap management, the tannins will be higher and the color more intense.
There are little cost implications for this process, unless the wines undergo some post fermentation maceration and oak maturation.
Explain the key differences between whole berry and whole bunch fermentations.
Whole berries with crushed fruit will undergo some intracellular fermentation but no carbon dioxide will be added to exclude oxygen. The level of associated ‘carbonic’ aromas will be less or more, depending on the proportion of whole berries to crushed fruit there is in the tank. Similar to semi-carbonic maceration, cap management techniques will be used to extract color and tannin. The style of wine varies as the proportion of whole berries vs. crushed fruit is variable.
Whole bunches with crushed fruit: in addition to the effects of whole berries, care will need to be taken to ensure that only ripe stems are added to avoid the addition of green flavors and unripe tannins. Ripe stems can add spicy or herbal flavors and also add some tannins.
Describe the process of post-fermentation maceration and identify the likely style, quality and price of wine a winemaker would be looking to achieve when using this method.
Post fermentation maceration involves leaving the finished wine on skins after fermentation for a period of time, normally a few days to a few weeks. During this period further tannin is extracted and the polymerization of tannins occurs which adds positively to the wine’s structure and texture, while improving the ageing potential.
This technique is really only suitable for premium red wines as the quality of the fruit needs to be excellent to start with and the wine style produced will have potential for ageing.
The cost associated with this technique is high due to tank space being used and the time taken to manage the wine.
At what percentage ABV would the fermenting must of a red wine be pressed when it has undergone carbonic maceration?
At 2%.
What are the effects of the use of malolactic conversion on red wines?
Malolactic conversion is almost always carried out for red wines.
It is often felt that malolactic conversion in oak barrels can lead to a better integration of oak characteristics during maturation.
Malolactic conversion will decrease the acidity and increase the pH of the wine.
