The Pinot Noir comes from our 8.5 acre vineyard in Northern Marin near the Sonoma border off of San Antonio Rd. It lies to the West of Mt. Burdell and Olompali State Park, two or three miles west of Hwy 101. It's roughly equidistant between Tomales Bay and SF Bay. The recently formed Petaluma Gap AVA crosses the border from Southern Sonoma into Northern Marin and encompasses my vineyard. I have a long-term lease on this piece of ground that is part of the much larger Cayetana Ranch.
I began digging soil sample pits on this ranch in 2000, prepped the vineyard in 2001 and planted in 2002. The 2004 vintage was the first harvest.
At this site, most of the weather comes from the Pacific rather than the SF Bay. The fact that I'm on a hillside that rises above the western side of the vineyard means that it is somewhat sheltered from direct west winds. Although the heart of the Petaluma Gap lies just to the North, my weather most often flows from the Southwest. On the occasional hot, high pressure day, things reverse, and I get a warm wind coming out of the Gap. Mt Burdell to the East of the vineyard affects the site by dividing the onshore flow of moisture. My vineyard tends to clear earlier in the day than most other sites within this maritime region because the fog and marine layer of low clouds often flow to the north and south of the vineyard as they move around Mt. Burdell.
The east facing aspect of the vineyard also bears upon its micro-climate. The great Pinot Noir vineyards of Burgundy generally slope eastward, and it's often said that this is advantageous because they tend to catch morning sun and thus warm up and dry out early in the day. I have a bunch of data loggers taking temperature readings every fifteen minutes on various prospective vineyard sites on the ranch. These sites vary by elevation and aspect. Looking at this data over the last several years, it seems to me that the more significant effect of an east facing slope is the way it skews temperature over the course of a growing season rather than each day. The current vineyard site will tend to be warm relative to some others early in the growing season, but by September, when the sun spends relatively more of the day in the western sky, it is the coolest. So, during the most crucial ripening period, an east facing slope will tend to be relatively cool. This is more advantageous for Pinot Noir than for other varietals that take more heat to ripen.
Good soil is hard to come by in Marin. It's all Franciscan sedimentary rock and soil that became very jumbled when scraped up from the seabed. Consequently, soils here seem to change every hundred yards or so. Most of it has too much clay or magnesium or is derived from serpentine parent material -- none of which is great for grapes. I had to dig hundreds of backhoe pits during the search for vineyard land to find a few patches of good soil. The soils in my vineyard are shallow loams (a good mix of sand, silt and clay) derived from shale and sandstone overlying clay loam subsoils. The 18" to 30" of topsoil on this vineyard are well drained, and I installed an extensive subsurface drainage system to move excess water out of the subsoil in the less steep portion of the vineyard more rapidly. Soil texture and drainage are important because vine roots do not like supersaturated conditions ("wet feet") during the growing season, because vine roots have a hard time penetrating heavy clay soils, and because these soils can hold too much moisture for the grower to be able to reign in the vines' vigor effectively.
Besides the slope of the vineyard and the subsurface drainage infrastructure, the third component of my drainage system, which I can adjust yearly, is the cover crop (the mix of grasses, legumes and brassicas grown between the vine rows). Besides opening up the soil, adding organic matter and hosting beneficial organisms above and below ground, the cover crop can be used to suck up excess moisture out of the soil. In wet years, especially those with a lot of Spring rains, I wait and let the cover crop grow head high before mowing it down. In dryer years, when I'm seeking to conserve soil moisture, I'll knock the cover crop down earlier and cultivate the soil to limit water loss to transpiration.
In general, I strive to have the vines arrive at a moderate water stress condition shortly after fruit set and berry formation. The idea is that stress will keep the berries small and signal the vine to put its energy into fruit maturation rather than producing a lot more shoot growth (vigor reduction). I try to maintain moderate stress through veraison (the point at which berries change from green to purple, soften and start sugar accumulation). Though more exact technological means of gauging stress are available, I mostly just look at the vines to get a feel for their water status. I've broken the vineyard into many small irrigation blocks based on observed stress patterns and can now apply water in a pretty fine tuned way. Once veraison is completed, I start to get more generous with the irrigation in an attempt to slow down the ripening process, to maintain the foliage which is starting to fade and to prevent sugar accumulation from occuring due to dehydration rather due to photosynthesis.
I planted seven Pinot clones in this vineyard -- 115, 828, 37, 667, 777, Pommard and a mystery clone that I got from Gloria Ferrer who got it from Trefethen who probably got it from Martini. So far, I like a combination of 115, 37 (a cleaned up version of the Mt. Eden clone) and Pommard best. The 115 tends to be the firmer, blacker tannic spine of the blend. The 37 is more elegant, floral and spicy. The Pommard is more fruit-forward, redder, dust cherry with an earthy backend grip. This scion wood is grafted (some in the nursery and some in the field) onto 3309 rootstock in the steeper parts of the vineyard and onto 101-14 rootstock in the less steep parts. These are both considered to be devigorating rootstocks, but the 3309 is reputed to be slightly more aggressive in chasing soil moisture.
The vine rows run North-South to provide even exposure to both sides of the vines and to provide mid-day shading of the fruit. This orientation necessitates some terracing across the steeper portion of the East-facing slope. The vines are planted 4 feet apart within the rows and 7.5 feet between rows. In all, there are about 12,000 vines in this planting. The vines are vertically trained through 3 sets of wires and cane pruned (a new cane, from which the current year's shoots will grow, is laid down along the fruiting wire very year). I converted to cane pruning from cordon pruning (a more permanent, old growth horizontal arm style) after several years of short harvests and have been happy with yields ever since.
Spacing matters with Pinot because shoots are usually closer together than with other varieties which produce bigger clusters. For example, I'll aim for about sixteen shoots per plant in both the Pinot and Syrah vineyards, but those sixteen shoots fit in 4 feet of Pinot cordon and 5 feet of Syrah cordon. The same sixteen shoots will yield twice the weight of fruit in the Syrah vineyard as the in the Pinot vineyard because the Pinot clusters are so small. Since things are a little tighter in the Pinot vineyard, we have to be extra scrupulous about thinning extra shoots and removing laterals. In the past I've also done leaf removal in the fruit zone on the East (morning sun) side to open things up, but more recently I've tried to avoid leaf removal when I don't face a lot of botrytis (bunch rot) pressure.
Harvest decisions are based on a mix of measurements, tasting fruit, and looking at the vines. Like most people, I want to pick before sugars get too high or acids drop too low. In tasting the fruit, I'm mostly looking for the flavors to evolve past the strawberry/raspberry phase into something darker. Beyond this I'm a little skeptical about the "picking on flavor" criteria that most winemakers now espouse. Most flavors and aromas that evolve during fermentation are not in perceptible form in fruit on the vine. Very high sugar certainly yields greater intensity of flavor in the fruit, but I don't really think people are picking up evolving flavor nuances that will be evident in the finished wine. I also think that waiting for the pinnacle of flavor intensity in the fruit is responsible for a lot of jammy Pinot Noir that can be mistaken for Zinfandel. When I'm tasting fruit, I'm more apt to split hairs over physiological indicators of maturity -- skin and pulp texture, seed color and brittleness, the way berries separate from the stems, the way pulp separates from the seeds, tannin quality, the way the skins release color. I'm also looking at the lignification (browning and hardening) of the stems and sometimes chewing them if I think they are candidates for inclusion in the fermentor. Finally, I'm also looking at the overall appearance of the vines. Sometimes you can just tell that a vine has nothing left to give and that any further evolution of the fruit will be in a pruny direction.
Each clone gets sampled and evaluated separately. There can be quite a spread amongst them, and I will pick each separately, if necessary. In 2005, the last clone was picked three weeks after the first clone.
In 2006, it rained so much in the Spring that it was difficult to subject the vines to water stress in a timely way. Berries were bigger than normal and the bunches were very full. 2006 has turned out to be by far my heaviest crop at three tons per acre. Spring rains combined with tight bunches will set up a vineyard for bunch rot later in the Fall. For this reason, in 2006, I was extra diligent about spraying for fungal suppression, and I went ahead and pulled leaves in the fruit zone to promote air movement around the bunches. This seems to have worked, as I had almost zero rot picking in late September while other growers at that point were losing substantial portions of their crop to botrytis.