Cullen Wines

26 Years of Wild Yeast Fermentation at Cullen, by Vanya Cullen

26 Years of Wild Yeast Fermentation at Cullen, by Vanya Cullen

26 Years of Wild Yeast Fermentation

Our 2016 Kevin John Chardonnay will be released on November 22, 2017, commemorating what would have been my father’s 95th birthday.

This release will also mark an astounding 26 years since we first began working with wild yeast fermentation at Cullen Wines.

The journey began in 1991 when UK journalist Robert Joseph visited the winery. After tasting our chardonnays he suggested the idea to me. Wild yeast was being used in winemaking in Burgundy, but it was never anything we had come across, even during the years I had spent at Roseworthy College. I was intrigued – it could work in France, but could it work here in Margaret River?

After five years of careful experimentation, in 1996 we produced our first chardonnay with 100% wild yeast fermentation. A decade later, by 2006, all of our wines were produced this way. It continues to be a wonderful, exciting, captivating journey every single harvest.

So what is wild yeast? Without delivering a science lesson, it is easily explained by simply saying we rely on the yeast that is already in the environment – on the grapes, in the winery, even in the barrels to allow the wine to ferment and turn the sugar into the all important alcohol. Even the aroma and the complexity of the wine can be influenced, so wild yeast in the local atmosphere lends itself to producing a uniqueness to the wine that cannot be found anywhere else.

We began by trialling wild yeast against cultured yeast we were using at the time; EC118. In every trial, the wine made with the wild yeast had better texture and complexity. It was the length and silky finish achieved which really made my mind up that this was the right course for Cullen.

For us it is a natural step in our journey of bringing the true terroir of our unique piece of Wilyabrup land to our wines. Dovetailing perfectly into our biodynamic viticulture philosophy, wild yeast helps us to keep our wines as natural as they can be, along with dry farming (no irrigation), no pesticides, no additions of inoculums, acids or fining agents and low levels of sulphur dioxide. We treat the whole vineyard as a living, breathing ecosystem.

Being biodynamic means we have an enormous amount of indigenous yeasts.  In fact in 2008 the Wine Institute of Australia conducted a study on the estate and found  over 400 strains of the sacromyces strain of wild yeast in the winery and 800 in the vineyard, so we can only imagine how many there are now! The prospect of further evolution of wine yeast within our vineyard is cause for excitement as our wines are increasingly expressions of the unique set of organisms, soil and climate at Cullen vineyard, promoting that unique terroir we cherish so much.

The alternate is to add commercial yeast, which is certainly more reliable and controllable, yet can also be manipulated to affect aroma and flavour. Wines made with commercial yeast, no matter how much or at what stage, are not generally considered natural wines.

Although a welcome and evolutionary step for our wine production, it was by no means an easy one. There were challenges and risks along the way, not only in the form of trial and error, but also the reaction from the wine industry in general. We were experimenting with something that was relatively new in Australia at the time and as with all new approaches, we were open to scepticism and ridicule. But we persisted, as to me it was all about finding ways to improve our wine.

For a great overview of wild yeast versus pure yeast cultures, read Huon Hooke’s article ‘Winemakers turn to wild fermentation’

‘And perhaps the most beautiful, exotic, fascinating wine of the day was Cullen’s Kevin John Chardonnay 2011. This was slightly feral and very exciting. It lives dangerously. Biodynamically grown and wild fermented, it’s a pioneer and benchmark of the genre. It’s so complex it’s difficult to describe, although honey and oak and what I call ”balsamic” (like the smell of balsamic vinegar, without the vinegar or sweetness) aromas are all involved, welded to a razor-sharp, crisply tart, long and linear palate structure.

It’s a great wine. But is it great because it was wild fermented? Probably the reason for its greatness is a combination of factors: great vineyard site, mature vines, expert viticulture and winemaking, and wild ferment are some of them.’

Huon Hooke,, July 2013 Read the full article here

Although a lot has been made of wild yeast fermentation being the new age way to approach winemaking, it is in fact the way wine was made for centuries. It was only in the 60’s that commercial yeast was introduced to improve reliability.

Producers of some of the greatest wines in the world recognize the value of these methods and have adopted their use in their wineries and vineyards. At the moment, criticism has been leveled at the Australian wine industry for the lack of natural and site distinctive wines. There is growing demand from world markets for naturally produced wines that display character that is unique to their vineyard sites. Cullen Wines are at the very forefront of a growing band of Australian producers adopting these techniques to lift our great wines to even higher levels on the world stage.

Many wineries who say they use natural yeast, actually add yeast in at the end of fermentation to finish, but being biodynamic, we don’t need to. I watch with interest all wineries (especially those who follow in our footsteps) who are experimenting and succeeding with wild yeast fermentation. It really is promoting the true art of winemaking to the fore, and looking at every opportunity to improve and bring our own unique terroir to our wine.

Vanya Cullen

Chief winemaker and Managing Director, Cullen Wines