native fermentation

sep 2020

Each pétproject wine is fermented naturally, utilizing native environmental yeasts. Native fermentations are dynamic- always unpredictable and lively. They present a challenge each harvest that I am happy to accept.

Each pétproject wine is fermented naturally, utilizing native environmental yeasts, as opposed to cultured lab yeast. I opt to use a pie de cuve to begin the fermentation- a small, potent "starter" from the site- which I begin about in advance of the bulk fermentation. This culture concentrate is then added to the rest of the grapes when they are picked to jumpstart the fermentation.⁠ I often compare this method to baking sourdough bread with a starter. Using this technique helps build up a nice yeast population, allowing the primary fermentation to take off strong.

To make the pie de cuve, I pick about 25 lbs of exceptional looking fruit at a vineyard about a week before harvest. I hand destem this fruit into a carboy and use what looks like a large 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, and I check these vineyard-specific fermentations daily, doing mini-punch downs. After 3-4 days the fermentation taking place becomes visible- bubbing and releasing gases. When I make still red wines at Foundry Vineyards using this method, I pour the pie de cuve into the fermenter when the harvested fruit is added, but for white wines and pét-nats I add it to the pressed juice after it has settled and been racked off to a new tank, a day or two after pressing.

I opt to create pie de cuves because, like sourdough, these starters and add complexity and nuance that could be lacking in a fermentation made from rehydrated yeast. Also like a sourdough, each starter is different- a reflection of the air, soil, and terroir of the vineyard. Yet despite providing distinct and unique flavors, native fermentations are still uncommon in winemaking. Natural ferments are by nature, uncontrolled. On one hand they offer intense flavor, unique to their specific terroir; on the other hand the fermentation process can be slightly less predictable and require more work (pampering or wrangling, depending on how you see it). However, I am not interested in making a “predictable” wine in a forced way. Because there are no additives, these wines can’t be like a recipe- it’s just one ingredient. I think about it in the same way that you might think about a craftsman honing a skill. The result is stylistically consistent in terms of quality, yet the product is always unique, dependent entirely on the qualities and personality of the raw material.

Native ferments are always dynamic- unpredictable, engaging, and lively. They present a challenge each harvest that I am happy to accept. I use this method to continually improve as I try to create wines with a true representation of fruit and site.

winemaking, natural