Joe’s Winemaking Notes: January 2016
It’s winter in Wine Country! Rainy weather has continued to alternate with cold, clear conditions over the past month. We’re now just beginning to see the potential effects of the largest El Niño, in an entire generation. So far, we’ve received approximately ten inches of rainfall, at our estate vineyard. I expect our totals to increase rapidly, as warm tropical storms blow our way. In studying our soil moisture profiles, and using probes at several locations in the vineyard, I can see that our soils are beginning to saturate as deeply as four feet below the surface! Much of the remaining, winter rain will percolate down to the aquifer, resting above bedrock at 180 to 200 feet. This is another great benefit of our Goldridge soil. Even in dry years, we have sufficient water resources and a healthy aquifer.
Nighttime temperatures seem to have bottomed out at 24 degrees Fahrenheit. We also have a few warm days briefly reaching the low 60s, before dropping back to nightly temperatures in the 20s and 30s. This is quite typical for this time of year in Sonoma County. As a child, I remember hearing that cold weather is good for you. On icy December mornings, I remember that smile, and hope the vines feel the same way!
Sur Lie Chardonnay
Our barrel fermented Chardonnay is continuing its slow progression through malolactic (ML) fermentation (a topic introduced last month). It’s now receiving weekly stirrings of the wine solids (called lees) settling in the barrels. This is accomplished by rolling the barrels on special racks, which mixes the lees into suspension. It might seem like a strange process when first introduced to wine consumers, since the ideal for a finished wine is to have great clarity, a “brilliance” even. With that clarity being our ultimate goal, why would we want to keep rolling and mixing the barrels?
(Pictured below: Bright clarity of finished wine on left versus unstirred wine on right.)
Sur lie (on the lees) aging, with regular mixing of the lees, provides many benefits to our Chardonnay. The primary benefit is an added textural richness. It also has a benefit of protection for the young wines from early oxidation, allowing us to use a lower level of sulfites to keep the wine fresh. (You’ve likely seen “contains sulfites” on wine labels, and I’ll be sure to visit that topic in another Winemaker’s Notes.) Oxidized white wines exhibit dark yellow or brown coloration, and lose many of their signature fruity aromas, which are then replaced by nutty or even vegetal aromas. With such beautiful Chardonnay grapes grown in the Green Valley of Russian River Valley, we do everything possible to protect their expression! Lees contact is a great way to accomplish this goal.
After the yeasts have completed the primary fermentation, and their food sources (glucose and fructose sugars) are depleted, the yeast cells will begin to die and break down (lyse). Some cell components are released from dying yeast cells, including polysaccharides [pälē’sakərīdes]. These components round out and add a sense of fleshiness to the wine. Meanwhile, mannoproteins help to balance out astringent tannins that have been leached from the oak barrel. During barrel aging, these yeast components will be slowly released into the wine. We promote their release by frequent stirring of the lees.
In December and January, we’re rolling the barrels on a weekly basis, tasting regularly, and monitoring the progress of the ML fermentation. We’ll be looking for a balance of acidity and the presence of diacetyl [dī-ē-‘sēt-əl]. This is the butter component, a result of the ML fermentation that creates a general softening of the wine. Each vintage is different, but a typical year finds us stirring lees weekly, until sometime in late January. We then move into a biweekly stirring, lasting into spring. As we get closer to blending and bottling, we’ll eliminate stirring entirely. This allows the lees to settle more compactly, and gives us a clean transfer of brilliantly clear wine to the bottling tanks.
Review of Pinot Noir Fermentation Lots
One of the most enjoyable aspects of my job (Surprise!) is tasting wine.
The task is even more pleasant, when I’m tasting our Green Valley Pinot Noirs from a year as powerful as 2015! You can see from the photo how densely purple-red the colors of the Pinot Noirs are, and that impact is just as strongly felt in the aromas, flavors, and textures of these wines. Although it’s early, we’ve begun classifying the vineyard blocks with the highest potential, and determining ways to apply lessons from the 2015 vintage. These review tastings are a monthly exercise for every wine we produce.