By Johnathan Grieve & Corne Marais
“Natural Fermentation allows for our wine to reflect its unique character in its texture, mouthfeel, body, flavour, elegance, and complexity, providing the unique sense of place, as Mother Nature intended.”― Johnathan Grieve

At Avondale, we practice organic & biodynamic farming methods to ensure full sustainable farming. No chemicals are used in the vineyards or the cellar, nor are chemicals added to the grapes when they arrive at the cellar. All our fermentations are spontaneous and are naturally caused by the unique yeasts present on our grapes.

Using these organic and biodynamic methods results in Avondale having plenty of healthy yeasts present on the grapes. This distinctive and specific fingerprint of microflora reflects the microclimate in the Avondale vineyards and transforms the grapes into wine reflecting the terroir of the specific vineyard at Avondale.

We follow a natural ferment process, a process that does not follow the same fermentation curve as a wine that has been inoculated with commercial yeast.

Firstly, it will take a lot longer to start fermentation. The yeasts need to multiply at a stage where the grape juice is vulnerable to bacterial spoilage. We minimise this risk by going to the specific vineyards we want to harvest 7 to 10 days before, picking some grapes and taking the grape must, putting it in a glass container, and letting the yeasts start multiplying forming a mother culture. By the time the block of grapes is harvested, the mother culture is already fermenting, and we just add to the picked grapes and the whole fermentation process starts quicker and the risk factor is reduced.

The second stage in the fermentation process speeds up, this is where most of the sugar gets converted to alcohol causing a temperature rise. We adopt the oxidative approach to winemaking, where the temperatures are much warmer during the ferment with ranges between 24 – 25 degrees for white, and 30 – 32 degrees for red at the peak of fermentation. In this process, you preserve the true core fruit which is awesome for age-ability, the essence of Avondale wines. 

The third and final stage of the ferment is in my opinion the most important. There is only 10-20g/l of sugar left and due to the high alcohol levels present, the natural yeasts struggle to convert the sugar into alcohol, causing the yeasts to produce esters. These esters provide the beautiful texture, “sweetness” and body to the wine. This stage also takes the longest as the yeasts battle to ferment this last bit of sugar. Natural ferments can take months to a year to finish, which is in sharp contrast to commercial ferments that take a couple of weeks to finish depending on the temperature they are permitted to ferment under.

In conclusion, natural fermentation is important to Avondale because the result allows each wine to express its unique character in its texture, mouthfeel, body, flavour, elegance, and complexity, providing the unique sense of place, as Mother Nature intended.

Qvevri with natural fermentation