14. Maturation Flashcards
What is racking (2)?
- the process of transferring wine from one vessel to another with the aim of removing sediment from wine
- wine is removed from original vessel through valve near bottom of vessel (above sediment) and poured or pumped into top of new, clean vessel
What is micro-oxygenation and how is it measured?
Where/when is it carried out?
What types of wines is it used for?
- a process that involves bubbling oxygen through wine in units of mg/L per month
- carried out in stainless steel tanks for a number of months post-fermentation
- initially used for cheaper wines, now premium/super-premium wines also using
How does the age of an oak barrel change its effect on the wine maturing inside (3)?
- New wood = more extractable compounds (tannins / aromas), stronger effect on wine.
- Barrels lose compounds w/each usage (~50% lost after first use)
- Very little if any compounds are extracted by wine by 4th usage.
What are the 3 key factors that have an impact on wine during maturation?
Oxygen / New Wood / Lees Contact
What are some things that purposeful oxygen exposure can lead to (4)?
- reduction in primary aromas, increase in tertiary (e.g. dried fruits/nuts)
- change in colour in white wines (darker colors, e.g. gold)
- better colour stability/intensity in young reds (becoming paler/browner w/extended oxidation)
- softening of tannins in red wine.
In terms of style, why would a winemaker choose to avoid new oak barrels?
What can be done instead?
- New oak flavors may be too dominant / clash with natural flavors of wine (e.g. aromatic varieties)
- Winemakers might choose to entirely use used oak barrels, or a mixture of both used and new in order to create the desired flavor profile.
What is an example of a wine whose high level of oxidation is a key part of its style?
How does this manifest itself in the wine (2)?
e.g. Oloroso Sherry
Brown color / lack of fresh fruit on palate, more nut/dried fruit flavors.
Why do wooden barrels of maturing wine need to be topped up (2)?
- due to wine loss through pores of wooden staves.
- prevents ullage / excessive oxidation.
Other than its effect on wine, why is oak the most common type of wood used for vessel construction (2)?
- easily molded/shaped.
- Creates water-tight containers.
What is the difference btw/ gross and fine lees?
- gross lees: larger, heavier sediment particles that form quickly after end of fermentation (within 24 hours)
- fine lees: smaller particles that settle more slowly
What are some ways that wine is exposed to oxygen while being matured in small oak barrels (4)?
- oxygen released from pores in barrel
- gaps between staves
- bung hole
- during transfer of wine e.g. racking, topping up through bunghole.
Explain how oxidation leads to greater color stability and intensity in young red wines (2):
What is an example of a wine that particularly benefits from this process?
- In this reaction, anthocyanins (color compounds) bind w/tannins.
- This protects anthocyanins from being absorbed by yeast lees or bleached by SO2.
Particularly important for lighter-colored red wines, e.g. Pinot Noir.
Why do some winemakers blend wine for PRICE (2)?
- inexpensive wines may see blending of parcels to increase profitability.
- e.g. more expensive Chardonnay may be blended w/cheaper Trebbiano/Semillon to increase volume and decrease price.
What is “autolysis”?
What is “bâtonnage”?
Autolysis: The slow death / breaking down of lees and the release of compounds that result.
Bâttonage: Stirring of the lees.
Why do some winemakers choose to store newly fermented, finished wine in bulk instead of bottling it (4)?
- wines are bottled only when a customer has placed an order.
- more flexibility in terms of selling wine (using different labels / selling in bulk / blending w/other wines)
- more efficient use of space
- wine labels less likely to get dirty/ruined by humidity.
What is meant by “toasting” wood (2)?
What effect does this have on the wood?
What effect will this have on the wine?
- Toasting is heating wood staves so they are maleable and able to be bent into shape.
- Temp + length of heat exposure = “level” of toasting (low/medium/heavy-toasted)
- transforms tannins + aroma compounds in oak.
- contributes notes of spice, caramel, char, smoke.
What are some reasons for NOT blending wines (4)?
- legal restrictions on blending varietals/geographical areas.
- production of single vineyard wines to maintain character/quality.
- promotion of single vineyard vines = more rare/distinctive for marketing purposes.
- some varietals have signature characteristics that a winemaker would want to preserve, e.g. Sauvignon Blanc/Riesling.
What does the term “blending” usually refer to?
When can it take place?
- The mixing together of two or more batches of wine.
- Can take place any time, but most commonly just before finishing/packaging.
Give a specific example of where a specific type of oak barrel is used due to its grain-tightness (4):
Hungarian oak barrels are becoming more popular in NY State.
- Hungarian oak tends to be tighter-grained, allowing for a very gradual extraction of oak aroma compounds and tannins.
- This is appropriate for red wines produced in NY because they are usually medium in alc, body, tannins and flavor intensity.
- This leads to them not being dominated by oak-derived characteristics.
What temperatures are reds and whites stored at during maturation?
- whites: 8-12 C / 46-54 F
- reds - 12-16 C / 54-61 F