Ask the Winemakers: Barbera & Malbec – Next Steps

Here’s the numbers.  What are the next steps?  Can you help SHW member Roger?  Post a comment below.

BARBERA:
A local winery I’ve done some work for gave approximately 75 pounds of Barbera grapes this last weekend. My readings are: Brix 28, pH 5.3, TA .95. I added 1/2 tsp SO2. Any suggestions?

MALBEC:
Racked the Malbec this last weekend. My Brix seem to be reading at less than zero. Does that make sense? pH 5.0, TA .75 What should I be doing as we move forward?

 

Share and Enjoy:
  • Twitter
  • Facebook
  • LinkedIn
  • Google Bookmarks
  • email
  • Print
  • RSS
This entry was posted in Winemaking Help. Bookmark the permalink.

5 Responses to Ask the Winemakers: Barbera & Malbec – Next Steps

  1. Fernando Berton says:

    On the Barbera – you may want to do the following:

    1) Add water to reduce the brix from 28 to whatever you desire. The 28 brix will give you close to 17% alcohol depending on what conversion factor you use. As fermentation proceeds, the high alcohol could be toxic to the yeast depending on the strain.

    2) If you decide to add water, check the pH again to see if it went down as well. If you still need to adjust the pH, use tartaric acid so your pH drops to about 3.5 which is a more favorable environment for the yeast to ferment. Using Tartaric Acid will accomplish that. The amount of tartaric acid will depend on your estimated volume of must.

    3) Regarding the TA, I assume it’s 0.95% or 9.5 grams/liter. You can always adjust the TA after fermentation for the mouthfeel of the wine, which is what TA will affect.

    On the Malbec, since you said you racked the wine that means it’s been fermented so a brix of zero would make total sense. That means all the sugar has been converted to alcohol. You will want to adjust the pH of the wine because the amount of SO2 you add is a function of the pH, current free SO2 level, and volume. A high pH of 5.0 would require way too much SO2 to protect your wine and you would probably smell/taste the SO2 in the wine

  2. Don Koehler says:

    Roger,
    For the barbera, you have some classic foothill numbers, high acid, low pH, overripeness, waiting for the acid to go down. You can add yeast and proper nutrients, Go Ferm and Fermaid K and go with it now. Use a yeast that tolerates high brix and alcohol. Use 1.5 times the regular amount of yeast to deal with the high brix. One step some people use is to water back to help fermentation happen. Adjust the brix down from 28 to 26 or 25 by adding distilled water. Although acid additions are usually suggested for the added water, that would not seem to be needed here given your high acid already.
    Malbec: A brix below 0.0 is not unusual. A totally dry wine should read about -2.5 brix, since the alcohol generated is less dense than the water. Your TA is fine. Your pH looks like a typo. I have never seen or heard of a pH that high in wine. Standardize your pH meter and take another reading.
    Good luck, Don Koehler

  3. Al Piccardo says:

    Maybe you can find someone with a low PH, blend your 5.0 PH with a 2.5. Would get you a 3.7 ph. I have a zinfandel 2017 at 2.85 ph. I can give you about 2.5 gallons or 3 gallons to blend. If you blend about 2.5 gallons of your Barbera with 3 gallons of my Zinfandel you should’ve close to a 3.5 target Ph. Give it a try.

  4. Don Koehler says:

    Roger, I misread your barbera pH as 3.5 instead of 5.3 in my previous response. I still do not see how you are getting that kind of pH reading. I would be very careful about adding tartaric acid to reduce the pH in either wine, especially where the barbera already has a lot of acid.
    Don Koehler

  5. It is hard to believe that a wine would be at a pH of 5.3. I would send a sample to Lodi Wine Labs for analysis. When wine is above a pH of 3.8, adding more tartaric acid will make the pH go up instead of down. This is due to high potassium in the grapes.

    If you send a 50ml sample to the Lodi Wine Lab they will send via email a complete report from a breakdown of the types of sugars to YAN, 10 items. Cost $40.

Leave a Reply

Your email address will not be published. Required fields are marked *