Marquette and Foch fermentations are right on schedule. One of the objectives of fermenting red wine is to extract as much color and flavor from the grape skins as possible. Since the grape skins float to the top of the fermenter, they need to be regularly pushed down. One way to do that in a tank is to hook up our Pulsair system to the compressed air supply and have it inject air in huge bubbles into the bottom of the fermenter twice per day. These bubbles rise to break up and submerge the cap that consists of grape skins. In fermentations that take place in 325 liter totes, we manually punch down the cap twice per day accomplishing the same thing.
The yeast that we added right at the beginning of fermentation needs some additional nutrition about half-way through the fermentation process, so when the remaining sugar drops to about 12% (12 Brix), we will provide more yeast nutrient.
We processed the St. Croix on Monday and started fermentation of the Petite Pearl at the same time. Petite Pearl is a purple grape that will make a red wine.
Last Friday, we harvested Louise Swenson from the small planting at Meadowcreek East vineyard. This is will make a white wine.
We gave the St. Pepin we harvested last week an extended cold soak. That means that it was put in a tank and then chilled to allow solids to settle. We harvested it early while the flavors were what we wanted but before the sugar level rose high enough to allow an ending alcohol level of about 12%. So, we will add some sugar to increase sweetness of the juice and then ferment. We will use the same process with the LaCrosse.
We will also start a batch of a dessert wine with St. Croix.