Like our work in the vineyard, things are slowing down with our 2012 Pinot Noir. But that doesn't mean there's nothing happening. The juice became wine when it completed the alcoholic fermentation, so we'll refer to it as wine from now on. It's now going through malolactic fermentation.
In malolactic fermentation, malic acid is converted to lactic acid. Malic acid gives wine that sharper acidity, where lactic acid is softer. White wine like Gewürztraminer doesn't go through malolactic fermentation because the winemaker is looking for that acidic flavor, but almost all red wines do. One of the by-products of the malolactic fermentation is diacetyl, which gives some wine their buttery taste. In Pinot, it makes the wine less acidic.
We put oak staves in the tank to add oak flavor to the wine. It used to be that all wine was fermented in oak barrels. Fermenting in stainless steel tanks and adding oak staves or beans makes it easier to control the amount of oak flavor you want in the wine. Also, barrels lose their oak characteristic over time, which makes the barrel unusable for adding oak flavor. Think of a tea bag. The first cup is strong. The second cup using the same bag is much weaker. Barrels are fairly expensive to replace, while steel tanks last a very long time.
So how do you know when it's done? We go out to the tank every week or so and give it a good stir. We're liberating the malic bacteria from the bottom of the tank, along with the dying yeast. This adds flavor and mouth feel to the wine. Then we take a sip, to make sure it's heading in the right direction. That's my favorite part. We'll be doing this for several weeks.
At some point, Clay will do a malolactic chromatography test to verify that the malo fermentation is complete. At that point, the wine will sit in the tank for probably a year to 18 months. Red wine is not for the impatient consumer.
To see the evolution of these grapes from harvest to bottling: