In 2010 University of Auckland researcher Dr Mat Goddard proved for the first time internationally that yeast (S. cerevisiae) is a significant part of terroir. He did this by isolating this yeast in New Zealand vineyards.
Natural ferments, as they’re called, have been used by some winemakers for a long time, but the study proved for the first time that this wild yeast strain was present in the vineyard, not just in the nooks and crannies of the winery. He also proved that on average New Zealand isolates shared less than .4 percent of their genealogy with strains of S. cerevisiae found elsewhere in the world.
A later study also proved that different regions in New Zealand have different yeast strains. That is, Marlborough has a different population from Central Otago and so on. Does this explain some of the regional differences we are beginning to see in our Pinot Noirs?
The yeast is designed to invade high sugar organisms such as fruit, but when the stalks,stems and fruit isn’t available Dr Goddard’s studies proved that it hangs out in the soil, vine bark and even the flowers found in the vicinity of the vineyard.
The next question could be whether each vineyard has its own population of yeast strains. If so, to say a wine truly has a sense of place, it makes sense to use grapes in that vineyard to start the ferment. It also raises some interesting questions about the influence of organics and biodynamics, with their focus on soil microbes. On the other side of the coin, what do systemic fungicides do to the yeast population?
The studies continue and it’s exciting that New Zealand is at the forefront of this research. In the meantime many wineries are using starters made in the vineyard to begin the fermentation of their wines.
One such winery is Black Estate in the Waipara Valley, and they took their inspiration from Mike Weersing in the nearby Pyramid Valley. Here’s a video of Black Estate vineyard man Alistair Blair explaining the process:
Winemaker Nicholas Brown creates a number of replicates of these starters and chooses the best one to inoculate his ferments with. He uses smell and even a microscope to identify S. cerevisiae. This helps to reduce the chances of unpredictable ferments.
A Black Estate vineyard starter fizzing nicely.
It takes the saying ‘wine is made in the vineyard’ to a whole new level.
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