Sparkling Flashcards
What should be done after primary but before secondary fermentation?
For traditional method wines, the final blend should be stabilised for tartrates and proteins before being bottled for second fermentation.
What is liqueur de tirage?
a mixture of wine and/or must, sugar, cultured yeasts, yeast nutrients and a clarifying agent such as bentonite and/or alginate (seaweed extract to facilitate riddling).
How much sugar is in the liqueur de tirage? how much alcohol does it become?
In most fully sparkling wines, 24 g of sucrose per litre is added. During fermentation, the yeast converts the sugar to alcohol (about +1.5% for an addition of 24 g/L of sucrose) and CO2. Unable to escape from the bottle, the CO2 produces a pressure considered appropriate for most sparkling wines, namely six atmospheres (also referred to as ‘bar’). Less sugar will be added if the winemaker wants to create a sparkling wine with lower pressure. The sugar added at this stage does not affect the final sweetness of the wine as the yeast ferment the wine to dryness.
What is needed in yeast for sparkling wine?
being able to ferment at 9.5–11% abv, at a moderate temperature of around 16 ̊C (61 ̊F) and pH values often below 3, and later withstanding high pressure as it completes fermentation in the bottle. Yeast cells must also flocculate readily to produce a coarse sediment that can be efficiently removed by riddling.
What happens after liqueur de tirage is added?
The bottles are stored horizontally ‘sur latte’ at a constant temperature of approximately 10–12 ̊C (50-53.5). The length of the fermentation depends primarily on the temperature. A cooler temperature results in a slower fermentation, and some claim that this produces a more complex finished wine. In many cases, the fermentation lasts 4–6 weeks.
disgorgement
re cooled to approximately 7 ̊C (45 ̊F) and the necks are immersed in a bath of frozen brine. This quickly freezes the yeast sediment in the neck, easing its extraction and ensuring the sediment does not fall back into the wine when the bottle is turned upright. Cooling also increases the solubility of carbon dioxide and so reduces the likelihood of the wine gushing upon opening. The disgorging machine inverts the bottle (so that it is now upright), removes the crown cap and allows the pressure within the bottle to eject the frozen yeast plug. Liqueur d’expédition is added before the bottle is fitted with a cork, wire muzzle and metal capsule.
dosage
The perception of acidity rounds out with age, thus the older the wine at disgorgement, the smaller the dosage required. However, at least some sugar is usually desired to encourage the development of classic post-disgorgement aromas. The sugar in the liqueur d’expédition reacts with compounds formed during yeast autolysis in a process called the Maillard reaction. This encourages the development of roasted, toasted vanilla aromas,
