Scott was asked to be on a panel at the Unified symposium held in Sacramento last week. This is the largest event of its kind in the western hemisphere. 11,000 people attended this event. Below is a synopsis of Scott Harvey's comments on high altitude/high latitude grape growing.
I was first bitten by the wine bug as an AFS exchange student to Germany in 1972. I was placed in a wine growing area, the Rheinland Pfalz, and helped the extended family both in the vineyards and in the cellar.
Having grown up in the Sierra Nevada, my first job in the California Wine Industry was in 1974 at Montevina winery in Amador County. It was during that harvest that I decided to become a winemaker. I made my way back to Germany, and staying with the same exchange family attending the Weinbau Schule in Neustadt and served an apprenticeship at Weingut K Fitz-Ritter in the high latitude vineyards of Germany’s Rheinland Pfalz.
Since, my winemaking has taken me from the high elevation Sierra’s (1,600 to 1,800 foot elevation) to both the low elevation Napa Valley floor and the high elevation vineyards of Napa Valleys Atlas Peak area (approx. 2,000 foot elevation).
Both high latitude and high elevation grape growing produce distinctive wines well worth the extra effort. All winemakers have to determine what the particular regional characteristics are, both desirable and undesirable, and figure out the regional practices to best produce distinctive wines showing both regional and varietal character.
Lets first address high latitude
Under our Jana label we produce two Rieslings. One is from the Rutherford Bench of the Napa Valley floor which has a latitude of 38.5 degrees and an elevation close to sea level. The other is a Riesling from Michigan’s Leelanau Peninsula at a latitude of 45 degrees. Being German trained I have a hard time staying away from cold climate Riesling. With both wines I’m trying to produce a style known in Germany has “Halbtroken Kabinett”. A Riesling that generally is off dry (.8% residual sugar) low alcohol (9.5 to 10.5%) low pH (2.9 to 3.1) wine. In any wine you make, you will need correct grape maturity so the wine can show both its regional and varietal character with out an underlying unripe green tone or overripe plumy flabby tone.
With the Napa wine I can harvest as soon as the grapes start yellowing at 17 to 19 brix. The low elevation, lower latitude and ample sun give me enough grape maturity to produce this Riesling at 9.5% alcohol. The acidity will still be too low and an acid addition is usually needed to keep the pH down at the 3.0 level.
With the Michigan Leelanau Peninsula Riesling at its higher latitude, colder climate and less sun I can not get grape maturity until they reach a higher brix. The Michigan northern latitude will cause the Riesling to bud out a full month to six weeks later than the Napa Riesling does. Therefore a much later harvest date due to both the later bud break and the higher brix needed for grape maturity makes it more difficult to produce a great wine year in and year out, but when it does the wine is exceptional.
The Napa wine produces a good wine year in and year out but will be less likely to produce an exceptional wine. Of similar quality, the Napa wine will have less alcohol and lower residual sugar to balance the higher pH while the Michigan wine will have a little more alcohol and a slightly higher residual sugar to balance the naturally lower pH.
Both the northern latitudes of New York and Michigan produce some of America’s greatest Rieslings. In an article published in Bruce Cass’s Wine Lab he states “500 feet of elevation has much the same effect as one degree of latitude”.
Now let’s address high elevation
We produce red wines from both the Sierra’s Amador County (1,600 ft to 1,800 ft) and from the Napa Valley floor (just above sea level). I also produce wine on a consulting basis for a Napa Atlas Peak winery (average elevation of 2,000 ft).
Both Atlas Peak and Amador County will bud out three weeks to a month after Napa’s Valley floor does. The grapes from Amador’s warmer and drier climate will catch up to Napa’s Valley floor while the Atlas Peak grapes will mature three to four weeks later. Both of these high elevation areas present their own particular growing conditions that require the grape grower/winemaker to develop the regional practices needed to accentuate the regional and varietal character in the finished wines.
In Amador County most of the vineyards are dry land farmed from older head pruned vines. Late in the growing season the brix levels will increase beyond levels needed to produce a 14.5% alcohol wine with the fruit still not mature. The vines will actually pull moisture out of their own fruit producing a golf balling or pebbling look to the grapes. If not careful one will produce a high alcohol green tasting wine. I have found the best wines in Amador County are always produced after the first rain. As in the recent 2009 harvest, the fruit before the first big rain was going over 27 brix while still not reaching maturity. After the rain, the brix dropped back to 22 and the grapes plumped back out. By the second time the grapes started pebbling again with sugars of around 24 the maturity was there and the best wine was produced making wines that both are identifiable as Zinfandel and Amador at around 14.5% alc. Amador doesn’t always get an early rain in harvest. For those vineyards that have drip irrigation, I’ll ask the grower to drip the vines trying to create the effect of an early rain and reverse the dehydration.
In Atlas Peak, all the vineyards are planted on thin rocky soil and would not produce much of a crop without drip irrigation. Here, irrigation is key to getting the grapes through the later than normal growing season. Since the soil is so varying one needs to go through the vineyard and increase or decrease irrigation from spot to spot or vine to vine.
Randle Johnson talked earlier today about high elevation amplification creating non-uniformity, varying maturity rates and high tannin levels. These are all things the grape grower/winemaker needs to pay attention to and develop the techniques needed to deal with them. High tannin levels in Amador County Zinfandel may be dealt with by using a small amount of carbonic maceration in the fermentation. In the case of the Atlas Peak Cabernet Saivignon, the excessively high tannin levels may be dealt with by pressing of the skins a little earlier. Personally, I have grown to like the non-uniformity, because I like producing wines that are more multi dimensional. High elevation grape growing and winemaking require more attention and the resulting wines are well worth the effort.