Sparkling Wine Production Methods Flashcards
Harvest: (Traditional Method- White Wines)
Usually by hand to ensure whole, healthy berries, minimising phenolic extraction and oxidation. Lower must weights than still wines are generally desired. The best sites for premium sparkling wines are cool and deliver grapes that have no unripe green flavours, low levels of sugar and high acid
Whole- bunch pressing: (Traditional Method- White Wines)
Gentle Pressing of juice with minimal phenolics. Especially important for red grapes. Pressing with stems provides channels for juice to escape minimising pressure required. Permitted levels of extraction often limited by law.
First Ferment: (Traditional Method- White Wines)
Usually rapid, and can be warm and oxidative; the esters typically produced by cool fermentation (such as banana and pear drops) are not desirable. Stainless steel commonly used; oak vessels favoured by a few producers. Malolactic fermentation may be encouraged to reduce excessive acidity and lend a certain profile of aromas. Base wine may be matured in stainless steel or barrel; time periods vary depending on producer.
Blending: (Traditional Method- White Wines)
Numerous base wine parcels may be blended. On a basic level this can include wines from different vineyards and grape varieties, but also may incorporate parcels of wines that have undergone malolactic fermentation, oak fermentation, or oak aging. Reserve wines from past vintages may be added to the blend and these may be stored in a variety of mediums including oak, standard bottle or magnum. Non- vintage blends aim to retain a house style, whereas vintage wines can be more unique.
Bottling and Triage: (Traditional Method- White Wine)
Addition of sugar, yeast and yeast nutrients (and riddling agents). A triage of approximately 24g sucrose per litre is needed. The sugar source can come from a beet, cane or grape base. Specific strains of inoculated yeasts are commonly used for both primary and second fermentation to minimise off- aromas and to achieve a consistent result in unfavourable fermentation conditions. Selected strains of Saccharomyces can function at the level of alcohol and sulfur dioxide concentration, low pH and low temperature typical of second fermentation. Bottles are typically sealed with a crown cap and stored horizontally.
Second Fermentation: (Traditional Method- White Wine)
Slow (takes 4-8 weeks) and conducted at low temperatures (around 10 degrees). The CO2 formed cannot escape from the closed bottle and dissolves into the wine. A pressure of 5-6 atmospheres and 1.2-1.3% abv is created.
Less Aging: (Traditional Method- White Wine)
Minimum of 9 months for most sparkling wines. Yeast autolysis creates toasty, ready flavours and reduces the risk of oxidation.
Riddling: (Traditional Method- White Wines)
Gentle movements of the bottle to sur pointe (upside down) position so the yeast slides to the neck of the bottle. Sudden agitation should cause tiny fragments of dead yeast to be caught in liquid suspension. Usually by gyropalete (takes about 3 days) but may be done by hand (which can take 6 weeks or more). This may be followed by further ageing sur pointe.
Disgorging: (Traditional Method- White Wines)
Usually conducted mechanically for speed and quality control. The bottle neck is frozen in brine solution creating a plug of yeast and ice. When the crown cap is removed, the pressure inside the bottle naturally ejects the plug. Yeast beads and yeast membranes may simplify this process. Disgorging may also be done by hand (a la volee).
Topping up and dosage: (Traditional Method- White Wines)
Also called liqueur d’ expedition. This usage syrup determines the sweetness of the final wine. The interaction of the sugar syrup and the wine is complex, and a further period of ageing at this time can allow better integration. The dosage is made up in wines (sometimes including reserve wines) which can be used to make final adjustments to the taste and, if permitted, the colour of the wine.
Transfer Method
Is the same as the traditional method, up to and including ageing.
The wine including the dead yeast deposit is chilled and transferred into a tank, where the wine is clarified (filtered), dosage is added and the wine is then bottled under pressure.
This is the method used in champagne for formats larger then Jeroboams, and most quarter bottles.
Tank Method
Also called the Charmat Method of the Martinotti method.
As for traditional method until bottling and triage. The base wine undergoes its second fermentation in a tank which retains the CO2 under pressure. The triage liquor is added to the tank to initiate this second fermentation.
Once a suitable pressure is reached (for example 5 atmospheres), fermentation is interrupted by cooling to -5 degrees. Dosage is added and the wine is bottled under pressure. Typically, fruit flavours are retained due to minimal lees contact (compared to traditional method). However, some producers choose to mature their wines in tank with periodic lees stirring to create wines with more yeasty attributes. Cheaper, faster and less labour intensive than traditional method.
Asti Method
A variation on the tank method.
Must storage- Must is stored at 0 degrees until needed (to retain freshness)
Fermentation- The must is fermented to approximately 5% abv and then held as a still liquid at near freezing temperature until the producer is ready to finish the fermentation process. In this last stage the CO2 is retained and dissolved. Fermentation is interrupted by chilling when foam forms and the alcohol is 7- 9.5% abv leaving some residual sugar.
Filtration- The wine is filtered under pressure to remove the yeast. Nitrogenous yeast nutrients must be removed to minimise the risk of fermentation restarting.
Carbonation
CO2 gas is pumped from cylinders into a tank of wine, which is bottled under pressure. The wine must be clear and stable, and otherwise ready for routine bottling. Useful for restraining aromatic fruit flavours but no high quality sparkling wines are made by this method. Bubbles can fade quickly.
Rose Production- Blending:
A red wine is produced and blended with the white base wine. The red must is fermented on its skins until it reaches 6% abv. The skins are then removed and fermentation continues until the wine is dry. This procedure provides a red wine that is suitably deep in colour but has minimal tannins. The proportion of red wine blended into the white base wine depends on the desired colour of the final product. It is important to note however that yeast cells absorb colour and the winemaker must compensate for this loss of colour during second fermentation in the original blending. Liqueur d’ Expedition can be used to rectify any problems as needed.
Rose champagne the only sparkling wine produced in the EU which can use this method. New world rose sparkling wines may also be produced by blending.
