Each pétproject wine is fermented naturally, utilizing wild yeast from the vineyard. Native fermentations are dynamic- always unpredictable and lively. They present a challenge each harvest that I am happy to accept.
Every pét project wine is fermented naturally, utilizing wild indiginous yeast from the vineyard, as opposed to cultured lab yeast. I opt to use a pied de cuve to begin the fermentation- a small, "starter" from the vineyard- which I begin in advance of the bulk fermentation. To jumpstart the fermentation, this culture is then added to the rest of the grapes when they are picked. I often compare this method to baking sourdough bread with a starter. Using this technique helps build up a healthy and diverse yeast population, allowing the primary fermentation to take off strong. I have been asked on occasion if this process yields the same result as leaving the grapes and must to ferment on their own, completely untouched. In fact, it can be almost the exact same result, however, using a pied de cuve is more intentional, it promotes a healthier fermentation and in my opinion adds an element of craftsmanship to an otherwise uncontrolled process.
To make the pied de cuve, I pick about 25 lbs of exceptionally healthy looking fruit at the vineyard about a week before harvest. I hand destem this fruit into a large-mouth glass carboy and use what looks like an oversized potato masher (it’s actually a large potato masher) to crush the fruit and make a mash of juice and skins. The environmental yeasts get to work eating the sugars. I check these vineyard-specific fermentations daily, performing mini punch-downs. After 3-4 days the fermentation taking place becomes visible- bubbling away.
I opt to create pied de cuves because, like sourdough, these starters add complexity and nuance that could be lacking in a fermentation made from rehydrated yeast. Lab cultures are akin to a monoculture, made of only a single strain of yeast, while native ferments capture the biodiversity of naturally occurring yeasts. Also like a sourdough, each starter is different- a reflection of the air, soil, and terroir of the vineyard.