41 - Sparkling Wine Production Flashcards
requirements for growing grapes for sparkling wine
- The grapes should ideally be relatively low in sugar compared with those used for still wines. The second fermentation that gives most sparkling wines their bubbles also increases the alcohol levels of the wines by a further 1,2-1,3% abv. Therefor winemakers will generally aim to produce a still dry base wine with 10-11% abv.
- High acid levels are desired for many sparkling wines, which are made in a refreshing style.
- Despite the relatively low sugar concentration & high acid levels, the flavours of of the grapes must still be sufficiently ripe so that they no longer have any green herbaceous flavour characteristics
meeting the requirements for the grapes for sparkling wine can be difficult in all but the coolest regions
Why?
- in cool regions the changes to the sugar & acid levels happen slowly & at the same time as the changes to the grapes’ flavours
- in warm regions sugar levels can rise & acid levels fall very quickly
–> picking early to get the correct levels of sugar & acid is the only option
–> this often means picking grapes that are still overly green & Herbaceous - finding an area with a sufficiently cool climate is fundamental to growing grapes for premium sparkling wine production
handling the grapes & juice for sparkling wine
- to produce high-quality sparkling wines it is vital that the grapes & their juice are treated with care
Harvest
- the grapes for the best sparkling wines are typically hand-picked to retain whole bunches of unsplit grapes
- in warm regions where grapes are being grown for the production of inexpensive sparkling wines, machine harvesting may be the most efficient way of picking all the grapes before they accumulate too much sugar & lose their acidity
Pressing
- pressed asap
- gentle pressing (minimise extraction of any tannins & colour)
- avoid crushing (contact between skins & juice is minimised)
- in most EU regions legislation determines the maximum pressure that can be used during pressing & the amount of juice that can be extracted from the grapes
5 methods of making sparkling wine
- Traditional Method
- Transfer Method
- Tank Method
- Asti Method
- Carbonation
the choice of method for making sparkling wine
- in European wine regions the choice of method may be determined by local laws
- outside Europe, it will be informed by the style or quality of wine that the winemaker wants to make, or the costs involved
Traditional Metod
- indicates a wine that has undergone a second fermentation in the bottle in which it is later sold
the technique most often used to make premium sparkling wines
Traditional Method
the Traditional Method is … & …, but can often command …
- costly
- time-consuming
- the highest prices
principal steps in the Traditional Method after harvesting & pressing (7)
- Making the base wine
- Blending
- Second alcoholic fermentation
- Yeast autolysis
- Riddling
- Disgorgement & corking
- Bottle ageing
making the base wine for Traditional Method
- the first alcoholic fermentation usually takes place in large temperature controlled stainless steel vats
- some producers still use oak vats or barrels for some or all of their wines
- the resulting base wine is completely dry with neutral flavours & high acidity
- the winemaker will decide, based on the style of wine to be made, wheter the wine will undergo MLF and/or a period of maturation in oak before the second alcoholic fermentation
- most base wines are used the year after the harvest
- some wines are stored for use in future years
- these ‘reserve’ wines have an important role to play in the blending process
the blending process is very important in the making of sparkling wines & serves a number of functions
(Traditional Method)
- many producers aim to make their sparkling wines in a particular house style, particularly for non-vintage products.
- blending wines from different vineyards, grape varieties and/or vintages can help to achieve this house style year-on-year despite vintage variation - blending can be used to improve the balance of the wine
- f.ex, Chardonnay is widely considered to bring citrus fruit, finesse & longevity to a blend, wheras PN brings aromas & flavours of red fruit & more body - blending can enhance the complexity of the wine
- old reserve wines can bring flavours of dried fruit to the fresh flavours of the young wine
- some producers may choose to blend in wines that have been matured in oak to bring a broader texture & spicy flavours to the wine
- it is easier to achieve these aims if blenders have as many wines as possible at their disposal
- for this reason grapes are often fermented in many different small parcels, giving multiple blending options
describe how the second alcoholic fermentation in the Traditional Method is done & what happens
- a small proportion of liqueur de tirage is added
- the bottle is closed with a crown cap that includes a plastic cup insert
- the bottles are then stacked horizontally in the producer’s cellars at a cool, constant temperature
- a slow fermentation takes place
- the alcohol is raised by around 1,2-1,3% abv & the CO2 generated by the yeast dissolves into the wine creating the sparkle
- this creates pressure in the bottle equivalent to 5-6 atm
what is liqueur de tirage?
(5)
a mixture of … added before the second fermentation in the Traditional Method
1. wine
2. sugar
3. yeast
4. yeast nutrients
5. a clarifying agent
Yeast autolysis
- once the second alcoholic fermentation is complete the yeast die & form a sediment of lees in the bottle
- over a period of months these dead yeast cells start to break down releasing chemical compounds into the wine
- these compounds contribute to the flavour of the wine, typically giving bread, biscuit & toasty notes
- autolysis lasts for between 4 & 5 years, but has been known to continue as long as 10 years
- wines that spend longer on their lees normally develop a more pronounced yeast character
- once autolysis is complete, keeping the lees in contact with the wine can maintain the wine’s freshness for years
Riddling
- after the period of maturation, the lees sediment is removed using the two processes of riddling & disgorgement
- riddling involves moving the bottle very slowly from a horizontal to an inverted vertical position
- the yeast sediment is dislodged & gradually slides down the side of the bottle collecting in the plastic cup insert in the crown cap
Traditionally
- done by hand
- the bottles were placed horizontally in the holes of an A-frame rack called a pupitre & then each day they were given a gentle shake & a twist & raised slightly closer to vertical
- very labour intensive process
- took up to 8 weeks to complete
Nowadays
- riddling is usually mechanised so that the work can be carried out faster & in bulk
- the standard machine in use today is a gyropalette, a cage holding 500 bottles on a hydraulic arm, which is regularly rotated & inclined
- this simulates hand riddling but completes the job in a matter of days
what is a pupitre?
A-frame rack used in the Traditional Method for riddling bottles
the bottles were placed horizontally in the holes of a A-frame rack called a pupitre & then each day they were given a gentle shake & a twist & raised slightly closer to vertical
what is a gyropalette?
a cage holding 500 bottles on a hydraulic arm, which is regularly rotated & inclined - standard machine used in the Traditional Method for riddling bottles
disgorgement & corking
- once riddling is complete the neck of the upturned bottle is submerged in a very cold brine solution, which freezes the wine in the neck
- the bottles are then inverted into a normal upright position & the frozen wine holds the sediment in place, keeping the wine clear
- the crown cap seal is removed & the pressure created by the dissolved CO2 ejects the frozen wine taking the sediment & plastic insert with it
- the wine is topped up with liqueur d’expédition & sealed with a cork that is held secure by a wire cage
- this whole process is now fully mechanised & the time taken from opening to resealing the bottle is a matter of seconds
- this avoids a loss of pressure & reduces the risk of oxidation
what is Liqueur d’expédition?
a mixture of … added after disgorgement & before corking
1. wine
2. sugar
