Chardonnay barrel fermentation-preparing juice for fermentation
One of the all time great pairings in the world of winemaking is the fusion of oak barrels and Chardonnay. After whole cluster pressing the fruit I let the juice settle in tank at 50° F for (in this particular case) 34 hours. This temperature allows rapid settling and is cold enough to prevent spontaneous fermentation until I have a chance to rack (decant) it to barrel. 34 hours settling allowed for a sharp distinction between the clarified juice and the sediment at the bottom of the tank which then allows for a high recovery of juice.
You'll notice the juice in the glass in the photo below is rather brown. Chardonnay for me is the exception to the rule of preventing juice exposure to ambient air. In this case I want the juice to oxidize. The chemical components that oxidize at the juice stage can't later be material to oxidize at the wine stage, and this keeps the wine fresh and lively. The fermentation process (really the yeast itself) adsorbs the oxided components and it settles to the bottom of the barrel with the yeast after alcoholic fermentation is complete. The clarified wine is a proper white wine color and you'd never know just how dark the juice was in the beginning.
The clarified juice is then pumped to barrel and the magic begins. The photos below show the juice in an almost full barrel. Almost full because anything more would see the fermentation foam out of the bung hole. It's always fun to see just how much juice you can put in a barrel and not get any foam overs. This depends on the fermentation temperature and the kind of yeast you're using. Then you add the yeast ("pitch the yeast") and wait. It takes at least 24 hours before you see any signs of fermentation. Once the fermentation takes off you have to monitor the temperature and keep it in a safe range. Most white wines I try to keep it at 60° F but for barrel fermented Chardonnay this can creep up to 70° F. At 60° F fermentation takes about 14 days to complete.
I always use cultivated yeast in wine fermentation. "Cultivated" yeast is natural yeast selected from the environment in respected wine producing regions all over the world. They're selected for their ability to complete alcoholic fermentation without producing off aromas or flavors, and for other more technical reasons such as its ability to withstand high alcohol concentrations or low fermentation temperature. In this case I chose a yeast that produces very low levels of hydrogen sulfide (rotten egg aroma) which is a completely natural byproduct of yeast fermentation. Spontaneous fermentation (i.e. not adding cultivated yeast) relies on the yeast that naturally sticks to the skins of grapes in the vineyard and is a reflection of your specific environment - which may not give you the fermentation characteristics you're looking for.
The barrels you see in the photos are made from oak trees known for its tight grain (the Tronçais forest of France). It's the characteristics of French oak (spicy, perfumy aromas) that lend itself so perfect for Chardonnay production. Aside from obvious oak character, barrel fermentation and aging give wine a richness and sweetness on the palate that can't be reproduced with any other winemaking process. The process I've described here is the traditional method for Chardonnay production in the Burgundy region of France, and replicated successfully in many regions all over the world. Many wines made in the Mid-Atlantic region straddle the line in style between the fruit-forward and impactful wines of California and the more reserved and structure-forward wines of France.