Secondary fermentation
Secondary fermentation refers to a subsequent stage of fermentation that follows the initial alcoholic fermentation in winemaking. It plays a crucial role in both sparkling and still wines, influencing texture, flavour, stability, and overall style.[1]
Background
In primary fermentation, yeasts convert grape sugars into alcohol and carbon dioxide, creating the base wine. Secondary fermentation encompasses several processes, most notably the bottle or tank fermentation used in the production of sparkling wines, and malolactic fermentation in many still wines.[2] These steps have been refined over centuries, particularly in regions such as Champagne, where secondary fermentation underpins the traditional method of sparkling wine production.[3]
Characteristics
From a microbiological standpoint, secondary fermentation may involve either yeast or lactic acid bacteria. In sparkling wines, an additional dose of sugar and yeast is added to the base wine, which ferments in a sealed environment and generates carbon dioxide, creating effervescence. This process can occur in individual bottles (traditional method) or in large pressurised tanks (Charmat method).[4]
In still wines, secondary fermentation often refers to malolactic fermentation (MLF). This bacterial conversion transforms sharper malic acid into softer lactic acid, reducing acidity and adding complexity to the flavour and [[mouthfeel]. MLF is common in red wines and some whites, particularly Chardonnay.[5]
Use in winemaking
The use of secondary fermentation varies according to style and region:
- In sparkling wines such as Champagne, Cava, and some Prosecco, the secondary fermentation is essential for the formation of bubbles. Bottle-fermented wines generally gain additional complexity through lees ageing.
- In still wines, MLF provides microbiological stability and contributes buttery, nutty, or creamy notes. Winemakers may encourage, inhibit, or partially apply this process depending on the desired style.
- Some fortified wines and speciality styles also involve secondary fermentations, though these are less common and highly specific to regional traditions.
See also
References
- ↑ Robinson (ed.), The Oxford Companion to Wine, Oxford University Press, 2015.
- ↑ Boulton, Singleton, Bisson & Kunkee, Principles and Practices of Winemaking, Springer, 1999.
- ↑ Stevenson, Christie’s World Encyclopedia of Champagne and Sparkling Wine, Absolute Press, 2013.
- ↑ Jackson, Wine Science: Principles and Applications, Academic Press, 2020.
- ↑ Robinson (ed.), The Oxford Companion to Wine, Oxford University Press, 2015.