We spent a day with Dr. Phil Freese recently. He’s formerly head of viticulture for Robert Mondavi Winery as well as professor of viticulture at the University of California. He and his wife, Zelma Long, who began her illustrious career making wine with Robert Mondavi and gained renown at Simi Winery, both consult with us.

We find their experience, expertise and the perspectives they bring very stimulating. Part of their role is to challenge us to continue to think creatively. One pitfall we try to guard against is falling into the same old ruts in our thinking and planning. Good enough is simply not good enough in the pursuit of the ultimate.

As we began our conversation, Phil commented on the smoke-filled skies from the many California wildfires during the past two months and the question of smoke affecting this year’s grape crop, a topic of some concern in our industry of late.  People have speculated that photosynthesis may have been impeded, or that grapes, and thus wines made from them, may be “smoke tainted.”

Phil doubts that smoke will be an issue. In the first instance, he doesn’t feel that smoke and particulate matter are sunshine issues, that they shield vines from photosynthetic radiation. He points out that vines function differently under cloudy skies as opposed to in the shade (much as humans can be sunburned on a cloudy day, but not in full shade), and the smoky conditions are comparable to cloud cover.

To get smoke into the fruit, he said that fires would have to burn for some time right next to a post-veraison (after grapes soften and turn color) red wine grape vineyard. (There would be no problem with white grapes because generally the juice is quickly removed from the skins in winemaking.)

Smoke dissolves in the waxy cuticle on the skin of the grape berry, and most of it is not water soluble in juice. As alcohol levels rise in the fermenter, however, the combination of alcohol and heat can suddenly produce a smoked sausage aroma in the winery from smoke-affected fruit.

Phil has witnessed such results from smoke in South Africa, Australia and California. He reminded us of the 1981 harvest in east Napa when several Cabernet Sauvignon vineyards, a couple of Zinfandel vineyards and a Merlot vineyard were subjected to fires in close proximity and yielded tainted wines.

The Australians have the most experience with fires, he said. They have farmed essentially under drought conditions for a decade or more, with late season fires occurring in 2003 as well as during the past three vintages, 2006-08.

Because the smoke we encountered occurred at high levels and also mostly before the onset of veraison, he feels it’s a non-issue.

Speaking of veraison, we received an interesting comment on our last post from Amel Salvatierra, who asked what effect on development and final character the heat spike had on berries that were pushed to change color.

I can’t list the exact effects, but I know that those berries will be a little riper. We’re only talking a few percent of berries here - the extreme right (ripe!) side of the bell curve, if you will. We always get excited when we see that first color because it means we’re moving to another stage.

We strive for uniformity in our crop - the huge center section of that bell curve - and we thin to avoid the other, greener extreme. But in actuality you can always find a range of several degrees Brix within the harvest from a given vineyard, block, row or even vine. The final Brix may be a precise reading, but it’s an average.

Anyway, those early berries may be a little riper, but overall they constitute a small component and don’t have much effect on the resultant wine.

A week ago I walked our Nugent (Russian River Valley), Donum and Ferguson Block vineyards. It had been four weeks since the July heat spike when we saw that first color in the grapes. Then cool weather returned and the vines stalled. Around July 28th, everything moved again very swiftly. Within three days, we had 50% veraison or better in most of our blocks. And now we have full color. It all happened within a week to ten days.

So now I’m estimating that harvest will occur the second week of September. How do we calculate that? Well, the classic interval in our industry between bloom and harvest is considered to be 100 days.

But in our cool climate vineyards, normally (whatever that is) our harvest occurs 112 to 115 days from the date that we have 50% bloom. Another check after the fact is to count back from harvest 35 days, which should put you at 50% veraison. Again, in our cool climate, that interval is more like 45 days. And for the last three vintages, we have experienced long hang times that extended that period to as much as 55 days.

This process of prediction involves rules of thumb and not absolutes, and is tempered by experience and intuition. Since we had 50% veraison at the end of July, right now I’m predicting that we should start harvest 45 days later, the second week of September. Does that sound like smoke and mirrors? Well, that’s the fun of it. We’ll plan for it, then wait and see.

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