Kumeu River’s natural yeasts: now available at a store near you

One of the ongoing bones of contention within the wine world has been the use of natural or cultured yeasts in winemaking. Yeasts are an indispensable part of the winemaking process, since they are responsible for fermentation, which converts the sugars in the grapes into alcohol, and thus grape juice into wine.

As is well-explained in this article, many winemakers will use cultured yeasts to inoculate the tanks where the grape juice, with or without the skin and pips, have been placed for fermentation: adding cultured yeasts ensures a reliable, predictable fermentation, and even predictable flavor patterns, through selection of specific yeast strains that encourage fruity or spicy notes. It’s a clear advantage when you’re looking for precise results, especially when you’re making millions of bottles of, say, Yellow Tail.

Traditionally, though, wine has been made through spontaneous fermentation, meaning that the process starts through multiplication of the yeasts that are found naturally on grape skins, in the vineyard environment and, over time, in the winery itself, as fermentation cycles leave behind yeast spores that are only too happy to go to work year after year, just as they do daily in bakeries. The specific and complex set of yeasts found in each given winery contribute to giving the wine its personality and distinctiveness. Like the specific minerals found in the soil, which combine with enzymes to provide particular aromatic components and give a sense of terroir, the yeasts are part of a wine’s sense of place. Something which completely goes out the window if you start using a spoonful of ICV-D80 or Lalvin T306.

But the frontier between cultured yeasts and natural yeasts is less clear than you’d think. For instance, researchers from the University of Auckland are making a specific kind of natural yeast available for commercial use, to help make New Zealand sauvignon blanc more “typical”. Thanks to this research:

Saint Clair, Delegat’s, Pernod-Ricard New Zealand, Nobilo, Kim Crawford’s and Forrest Estate wineries will be using a newly discovered, naturally occurring New Zealand yeast to ferment grapes from this year’s harvest.

Where does this yeast strain come from, pray tell? From the very successful Kumeu River Wines‘ vineyard. So essentially, this lovely family winery has just handed a distinctive component of what makes its wines special to Pernod-Ricard and Kim Crawford, so that these big players could make wines from more generic places more like Kumeu River wines… To me, that feels as if you had just handed your grandmother’s award-winning secret recipe for cherry pie to ACME bakeries Inc. Here’s another quote from the article on this:

“Kumeu River has a philosophy in winemaking which uses the yeast that occurs naturally on the vines to ferment the grapes,” says Dr Matthew Goddard of the School of Biological Sciences. “By working with this very successful vineyard, we have managed to isolate a yeast which adds to New Zealand Sauvignon’s distinctive characteristics. This trial will let us see if the yeast will also work in a commercial setting.”

Oh great. Soon enough, winemakers in Chile, Virginia or the Niagara Valley will have more tools at hand to join in the great Kiwi/Grapefruit overdose. I’m not sure congratulations are in order.