Making Wine from White Grapes

1. Sanitize and Crush and Destem – Inspect your grapes and remove any moldy clusters. Crush and destem into clean and sanitized food grade plastic tubs. Always rinse your receiving vessel with a sanitizing strength potassium metabisulfite solution (2oz/gallon or 3tbsp/gallon). Make sure that the sanitizing solution touches all the surfaces of the vessel and that the vessel is completely emptied out of all sanitizing solution after. Shake free any drops as best you can from the vessel. Having remaining sulfite liquid in the vessel will prohibit fermentation. Do not rinse the sanitizer off with water after sanitizing as that will reintroduce bacteria to the environment.

2. Once all of the grapes are crushed, try to accurately measure your quantity of must. Add ¼ tsp of potassium metabisulfite for every 5 gallons of must that you have. Mix up the must thoroughly.

3. Wait for 2 hours after the sulfite addition and then add pectic enzyme to the must. Musto Wine Grape offers generic pectic enzyme or Cinn Free pectic enzyme that is specifically designed for white wine grapes. Follow the directions for the individual type of enzyme. Always mix it with water to create a 10% solution (if you use 5mls of enzyme, mix it with 45mls of water). The water allows it to better circulate throughout the must. Allow the pectic enzyme to work for 6 hours before pressing.

4. Press the Must – Wash the press and sanitize using potassium metabisulfite. Again, make sure the press does not have an excessive puddles or lingering amounts of sanitizing solution remaining. Sanitize the receiving container for fermentation (carboy, tank, demijohn, barrel) and any pumps or tubing that you may use. Anything that comes in contact with the wine should be rinsed with sulfite sanitizing solution. Place a screen or mesh (also sanitized) inside of the press to hold back any extra skins or seeds from getting through. Start by scooping up the must and placing it in the press. Some of the liquid will immediately flow through; this is the “free run”. When the press is full, slowly begin pressing. Do not try and press every last drop out of the must as this can lead to seed cracking and bitterness in the wine. Fill each container to within 6 inches of the top, to allow room for fermentation. This process will cause the juice to foam up and generate gas, therefore volume.

5. After pressing the grapes, mix the container thoroughly and take and record your measurements. Measure Brix, pH, and TA. If you need to adjust your juice at all, this is the time to do it. Ideally your Brix should be between 21-26 degrees, the pH between 3.2-3.5, and the TA between 6.5-8.5g/L. Your initial Brix reading, multiplied by .55, will give you a close estimate of your ending alcohol by volume percentage.

6. If you would like to use fermentation tannins (FT Blanc) or fermentation nutrients such as Opti-White, add them after measurements and adjustments have been made. Musto Wine Grape packages FT Blanc and Opti-White in small packs for 5 gallon batches. Mix any of these ingredients in thoroughly.

7. After measurements have been taken and any adjustments have been made, it is time to set yeast if you are using a cultured yeast strain. Use 1gram/gallon of wine must. Follow the yeast set directions on the packet explicitly and/or see the separate “Yeast Set” instructions.

8. After you atemperate and add your yeast, cover your tank with a floating lid or your carboy or demijohn with an airlock. An air lock will allow the carbon dioxide to escape the container without additional air getting in to oxidize the wine.

9. Stir the juice every other day to re-suspend the yeast and nutrients. Keeping the yeast in suspension is important to give it access to sugar and nutrients and to avoid the production of H₂S.

10. If you are using additional yeast nutrients to assist in fermentation you will add them after fermentation has started. Fermaid O is added at the beginning of fermentation (1 day after yeast set) and all others (BSG yeast nutrient, Fermaid K, AnchorFerm) will be added at 1/3 depletion of the Brix (2/3 of the beginning amount of Brix). Follow the directions for the individual yeast nutrient, hydrating with water and mixing thoroughly.

11. If you are adding malolactic cultures to your wine (Chardonnay), you may also chose to do this at 1/3 Brix depletion. If using a malolactic nutrient (Opti-Malo Plus) with the bacterial culture, hydrate the nutrient in a separate container from the bacteria and add to the must directly before the addition of the bacteria. Follow all directions on the bacteria and nutrient packets explicitly.

12. Monitor the progression of the juice by taking daily hydrometer readings. Using a sanitized wine thief or syringe, pull a sample of fermenting wine that is large enough to fill the hydrometer cylinder. Always sanitize the hydrometer and the cylinder before taking a reading. Look to the meniscus of the wine surface in relation to the hydrometer for the most accurate reading. When the wine is fermented to dryness (0.90 Specific Gravity), is has completed its primary fermentation. Allow the lees particles to settle, and then rack the wine into a sanitized container. Be sure that the container is filled within ½” of the top to prevent air exposure. At this point, it is imperative to add ¼ tsp of potassium metabisulfite per 5 gallons of wine. The sulfites will kill off any harmful microbes and prevent the wine from oxidizing.