Once the red wine is put into tanks and fermentation begins all of the solids—grape skins, pulp rise to the surface. This mass of solid matter is called must; however we refer to the floating section as “The Cap.” In order to maximize the extraction of color, flavor and structure we use one of several processes of cap management. There are many factors to consider when deciding how often to mix the cap, including the grape type, the growing season, fermentation temperature and whether or not the wine will have extended maceration.
Punch down - is a gentle process of submerging the skins that forms over fermenting red wine in order to improve the extraction of color, flavor and tannin structure. Punch downs are initiated before the yeast is added during cold soaking and then performed 2 to 3 times daily until the end of fermentation and sometimes beyond if extended maceration post fermentation is necessary to improve the structure and color stability of the wine. Because punch downs are the gentlest form of cap management it is generally exclusive to our reserve tier wines. A lot of work goes in to punching down several small lot ferments two to three times each day and therefor this input is focused on our best wines.
Pumpovers – This cap management method can be performed in a variety of ways. The process is to pump the juice from the racking valve, near the bottom of the tank, over the top of the tank and over the risen skins or cap. You can fit an attachment to the top of the tank that can irrigate the cap mechanically, or you can pump it over manually by holding on to the hose and directing the flow of the wine to wet the entire surface of the cap. This wetting process is where you maximize your extraction of flavor, color and texture.
Submerged Screen – This method involves installing a screen in the fermentation vessel to keep the cap submerged under the wine surface to maximize extraction. This system is very gentle; however, it is important to note that the skins will be very compact under the screen and the extracts will be minimal. Another cap management system will need to be incorporated to improve the extraction. I have used this system along with 2 punch downs daily and am very happy with the effect.
After the destemmer the wine is pumped into tanks to begin fermentation. The process of fermentation in winemaking turns grape juice into an alcoholic beverage.
White wines are typically fermented without their skins and other solids, while red wines are fermented in contact with skins and other solids.
By putting grape juice into a container at the right temperature, adding yeast which turns the sugar in the juice into alcohol and carbon dioxide the grape juice will ferment.
During fermentation, yeasts transform sugars present in the juice into ethanol and carbon dioxide (as a by-product). The temperature and speed of fermentation are important considerations as well as the levels of oxygen present in the must at the start of the fermentation. The more sugars in the grapes the higher the potential alcohol level of the wine if the yeast is allowed to carry out fermentation to dryness. We will stop fermentation in some cases early in order to leave some residual sugars and sweetness in the wine for example our Riesling. This can be achieved by dropping fermentation temperatures to the point where the yeast are inactive and then sterile filtering the wine to remove the yeast.
Fermentation may be done in stainless steel tanks, in an open plastic vat or inside a wine barrel. All of our fermentation tanks are heated or cooled by a controlled glycol system that runs through jacketed tanks. Red wine fermentation requires temperatures to reach 78.8 - 86°F for the pigments to be extracted from the grape skins. It is common to warm the fermenting juice artificially to help this happen. This has to be done carefully, as yeast die quickly in the heat. White wine fermentation may require the fermenting juice to be cooled to 53.6 - 59°F to help preserve the delicate varietal characteristics. These flavor and aromatic compounds are destroyed in high temperatures.