The last time I talked about the wine making process it was just the beginning. I covered the process of removing the stems from the grapes and transferring them into a plastic bin with dry ice. Because the dry ice cooled the grapes down considerably, they needed a few days to settle before being introduced to yeast.
Each day they sit they need to be punched down with a wooden tool to keep the skins from drying out and to also keep everything in the bin homogeneous.
Temperature and Sugar Levels
It’s important to test the grapes in the bin for sugar and temperature before adding the yeast. Testing the sugar level helps confirm the projected alcohol level. In this case, I wanted close to 23 brixs which should (hopefully) end up at a 13% alcohol if all goes well.
The temperature is tested to insure it’s warm enough for the yeast to survive. Ideally over 60º F.
Making wine at home – part two
Once everything has been tested and confirmed, it’s time to add yeast to our bin to start the fermentation process.
Preparing the Yeast
Yeast is a cell. It basically eats the sugar from the grape juice, otherwise known as must, and converts it into alcohol or ethanol.
The yeast needs a clean environment to thrive. Ideally, no pesticides, the right temperature and carbohydrates or sugar to process. When all these things align, it’s time to introduce the yeast.
Type of Yeast
I used a freeze dry type of yeast which needs to be rehydrated to become alive and activated. A bowl of warm water is tested for the the right temperature. I added some of the grape juice to slowly modify the chemistry of the water to emulate that of the grape juice. The temperate of this mixture needs to be between 35-40º Celsius before the yeast should be added to the mixture. Once the temp is reached, the yeast is sprinkled into the mixture and left alone for twenty minutes before it should meet its new environment.
When the yeast has risen and expanded it’s gently mixed gently. Then the yeast can officially be introduced to the bin of grape skins and juice in the gentlest way possible. This allows the yeast to continue to adjust without going into shock.
After the yeast is added to the bin, it’s punched down again for even mixing. This allows the grape skins and juice to evenly disburse their sugar for the yeast to eat and eventually turn into wine.
The next step is pressing the grapes and removing the skins! Stay tuned.