Wild yeast fermentation produces wine that can be referred to as “natural” wine and is a practice gaining popularity in winemaking circles globally, producing some interesting end products. You could say wild fermentation is to wine what raw milk is to cheese.
Fermentation is a biochemical process where the yeast consumes the sugar and converts it to alcohol and carbon dioxide. Yeast has a significant role to play in the winemaking process, influencing aromas, alcohol level, texture, acidity and other key characteristics.
It is typical for many wineries to control the fermentation process, primarily for the purposes of consistency in the end product. Many wine consumers like to know the wine we bought last year from a particular producer will be pretty much the same this year and the year after that, and this is achieved by controlling the fermentation and other processes of the winemaking process. Controlled fermentation is achieved by inoculating the must with a particular strain of yeast that imparts specific desirable characteristics to the fermenting grapes and the resultant juice.
Wild yeast fermentation is growing in popularity, with creative winemakers tapping into the market of more adventurous wine drinkers, who are looking for interesting and diverse flavours with unique complexities in their wines.
Allowing wine to ferment naturally does involve some risks, as it is dependent upon yeast that occurs naturally in the vineyard, on the grapes, in the winery, on winemaking equipment etc. Along with the yeasts that have a positive impact on the wine, there are those that can have a negative effect. This is where the winemaker’s role is imperative and requires constant testing of the wine, to ensure none of the nasties take hold and spoil the wine. But, it is the wild uncontrolled nature of these yeasts that brings forth interesting flavour, mouth feel, aroma and complexity.
Over time, the wild yeasts can be considered to be “tamed”. This occurs in wineries and vineyards that have existed for generations – vintage after vintage being made from fruit from the same vineyard and the wine being produced in the same winery environment. Over time, the wild yeasts can build up to a point where they are predictable and can be relied upon to consistently provide the desired characteristics to the wine. It is common in many of the traditional wine growing regions of France to be using wild yeast for their fermentation.
So, there is a little background on one of the latest trends in wine drinking, and if you are an explorer in the world of wine, natural wines will provide you with some interesting and new flavours. But be warned – if you find a wine you really enjoy in the natural wine world of the current vintage, you’d better stock up on it, as it most likely will not taste the same next vintage.