My 2008 Pinot Recipe

September 17th, 2008 → 9:01 am @ Josh Hermsmeyer


If last year was Darth Vader – all about extraction, enzymes, neutral oak chips and depth of color – this year is more zen Yoda. I basically said to the yeast: “do or do not, there is no try”. In short, ’08 is all about the old wine cliche “let the wine make itself”.

The wine is turing out wonderfully, and for that I blame Joel Peterson. Earlier this spring I had a chance to spend a few nights chatting with Joel and Morgan, tasting wines blind and talking shop while Morgan prepared for his Masters of Wine exam. I’m happy and proud to report that Morgan, a fellow blogger and winemaker, passed.

He is now one of less than 30 (correct me if I’m off here) American MWs. And Morgan is still a few years short of 30. Quite the accomplishment, to say the least! You won’t find a more down to earth, unpretentious MW anywhere. And that’s just the way it should be.

Anyway, during one of our conversations Joel asked me what I thought about native yeast ferments. I repeated what I was taught at Davis: that native ferments were unreliable, and that more likely than not the yeasts that eventually ended up doing the heavy lifting were cultured ones already present in the winery, not in the vineyards.

30 Yeast Enter, 4 Yeast Breed

Joel nodded and then proceeded to tell me about a series of intriguing yeast studies he oversaw at Ravenswood. A few years back he hired a yeast geneticist to study the native yeast populations at various vineyards under contract at Ravenswood. The geneticist catalogued each of the species of yeast he found and then tracked the development of each through fermentation. He did this over multiple seasons.

What the geneticist found was that around 30 species came in to the winery on roughly 5% of the grapes, and that only 4 ended up fermenting the juice. Each of the 4 yeast “winners” would then split up the ferment. For example, one species might feast from 20 to 13 Brix, and then would be outcompeted by a second yeast which was better suited to the now more alcoholic conditions of the must. These results held year over year, and could explain why many folks tend to favor native yeast ferments, lauding them as “more complex”.

Evidence For Terroir

But for me the real relevation was this: the 4 yeasts strains that ended up being “winners” and dominating the fermentation varied each and every year of the study. Indeed, the pool from which the victors came varied each year as well. The assumption is that conditions during the growing season select for different species each year. As Joel pointed out, yeast are fungi after all, and thus are heavily influenced by weather conditions.

This is a profound finding, and is perfect evidence of terroir at work. It was also enough to convince me to rethink my position on natural vs. cultivated yeasts in winemaking.

Joel has graciously given me permission to share his research, and hopefully those of you out there who have been reticent about experimenting with native yeasts will give it a go. As for me, I’m now one of the converted.

The labs for the grapes were similar to last year, with acids being noticeably higher. The big three looked like this:

  • Brix: soaked up to 27.4
  • TA: 7.5 g/L
  • pH: 3.44

Free Wine!

The only adjustment I made prior to ferment was to rehydrate. This is also the only similarity between this year’s recipe and last. Total H2O add back was less than 12%, with the rule of thumb being that anything less than 20% will not dilute flavor.

Some winemakers prefer to bleed off an equal amount of juice prior to the rehydration (as I did last year), and some even bleed off more than is added to concentrate the must further. The fruit this year suffered from some pretty severe desiccation however, so I felt that not only would my addition of Jesus Units this year help tame the high sugar, but would also bring about needed balance. Thus I did not bleed. Hey, it’s free wine!

After de-stemming I dosed the wine with ~30 ppm SO2 to stun the various strains of yeast (many of which would be responsible for off-odors and creation of volatile acidity) and initiated a cold soak with the addition of dry ice. Temps were held around 55 degrees for 4 days and then I allowed the must to gradually come up to ambient temps. 5 days after de-stemming fermentation began and is just now winding down. Peak temp observed was 87 degrees (which is good for maintaining some of the more delicate volatile aromas generated during the ferment, but not optimal for color) I’ll be pressing off tomorrow and going to barrel.

Interestingly, I was able to recognize 4 different stages during the ferment, which I assume coincided with the points at which the different yeast strains dominated. There was a slightly stinky sulfur stage, and a spicy/earthy stage bookended by two floral and fruity stages. Good times.

A Successful Experiment

As an experiment with an eye towards quality and complexity, so far this one has been extremely successful. There were no issues with the ferment, the “off-odors” generated by the native yeast stand a very high chance of contributing a complexity to this year’s wine lacking in the ’07, and inputs and interventions were minimal. This makes for less work on my part both now and down the road.

And finally, given Joel’s research into native yeasts, I believe that I can say with very high confidence that this vintage reflects the terroir of Rebecca’s vineyard and not just be blowing marketing sunshine up anyone’s tailpipe.

My thanks again to Joel and Morgan for the wine, food and the invaluable advice.

Pics and a video coming soon!