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Table for Acid Adjustment

Table for Potential Alcohol Adjustment

Table for Molecular vs. Free SO2

Table for SO2 Adjustment

List of Resource Web Sites

   Table for Acid Adjustment
Determine the current acid level by titrating, then adjust by adding Tartaric acid to bring the acid level to the desired level. Do not use Malic acid for two reasons: It is not as strong as Tartaric and the table values are not for Malic, and commercial Malic acid consids of 50% D-Malic and 50% L-Malic. If you want to do a subsequent malolactic fermentation, the lactobacillus can metabolize only the L-Malic acid, leaving D-Malic acid which you cannot get rid of and your malolactic tests will always fail. (Grams to be added per 10 gallons of finished wine)
Current
Acid
Target Acid
0.5 g/ltr 0.6 g/ltr 0.7 g/ltr 0.8 g/ltr
0.3 g/ltr  7.6 11.4 15.1 18.9
0.4 g/ltr  3.8  7.6 11.4 15.1
0.5 g/ltr - -  3.8  7.6 11.4
0.6 g/ltr - - - -  3.8  7.6
0.7 g/ltr - - - - - -  3.8
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   Table for Potential Alcohol Adjustment
If your grapes have not come in with a high enough Brix reading, you may need to add sugar to bring the alcohol up to a stable level. Anything above 12% alcohol is acceptable, but since alcohol adds body some winemakers like their wines above 13^, even 14%. However, be cautious. If the underlying fruit intensity doesn’t support high alcohol, your wines will take hot and unbalanced if you push the alcohol too high. (Grams to be added per 10 gallons of finished wine)
Current
Brix
Target Alcohol
12.0 % 12.5 % 13.0 % 13.5 % 14.0 % 14.5 %
22.0 Brix   420 1200 1980 2760 2560 4320
22.5 Brix - -  780 1560 2340 3120 3900
23.0 Brix - -  360 1150 1930 2710 3490
23.5 Brix - - - -  730 1510 2290 3070
24.0 Brix - - - -  310 1090 1870 2650
24.5 Brix - - - - - -  680 1460 2240
25.0 Brix - - - - - -  260 1040 1820
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   Table Converting Free to Molecular SO2
SO2 is used to protect your wine from microorganisms and from oxidation. It is the molecular level of SO2 that does the protection, and this is derived from free SO2. However, the amount that is derived is a function of the pH of the wine. The lower the pH, the more molecular SO2 is derived from the free SO2. Following is a table that converts free SO2 to molecular SO2. If your instructions call for keeping the free SO2 above a certain level, use this table to first convert to molecular SO2, then use the next table to determine the amount of potassium metabisulfite to add to your wine.0.8 PPM melecular SO2 is needed to protect your wine.As you can see from the table, even 100 PPM free is not enough to protect a 4.0 pH wine. (Molecular values for different free values, versus pH)
pH Free SO2 (PPM)
20 ppm 30 ppm 40 ppm 50 ppm 60 ppm 100 ppm
3.3 0.64 0.96 1.28 1.60 1.92 3.20
3.4 0.52 0.77 1.04 1.29 1.56 2.58
3.5 0.41 0.62 0.82 1.03 1.24 2.05
3.6 0.33 0.49 0.66 0.83 0.99 1.63
3.7 0.26 0.39 0.52 0.65 0.78 1.29
3.8 0.21 0.31 0.42 0.51 0.63 1.03
3.9 0.16 0.24 0.32 0.41 0.49 0.82
4.0 0.13 0.19 0.26 0.32 0.39 0.62
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   Table for Adjusting SO2
Adjust your SO2to keep the molecular level above 0.8 PPM.0.8 PPM melecular SO2 is needed to protect your wine.Assume that at the conclusion of fermentation you have 0.0 PPM free SO2. Subsequent additions require measurement or guesswork. Depending on the cleanliness (and oxygen exposure, a guideline to use is that wine will loose 10% residual value each month in barrel, and 20% at racking. The table below gives required additions in three units of measure:

  • Grams of potassium metabisulfite
  • Tablespoons of a 10% metabisulphite solution1
  • Campden tablets

1To make a 10% SO2 solution, add 72 grams (or 4.5 tablespoons)
of potassium metabisulfite to an empty 750 ml wine and fill with water.
Note: Only 57.6% of pot. metabisulfite is SO2.

(To be added per 10 gallons of finished wine to achieve 0.8 ppm
molecular, assume 0.0 ppm molecular start)

pH SO2 Addition
Pot. Meta. (g) 10% Solution (tblsp) Campden Tabs
3.3 1.6 1.1  3.75
3.4 2.0 1.4  4.75
3.5 2.6 1.8  5.75
3.6 3.2 2.2  7.75
3.7 4.1 2.8  9.25
3.8 5.1 3.5 11.75
3.9 5.4 4.4 14.75
4.0 8.1 5.6 18.50
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   References and Links
Books and Magazines

  • Grapes Into Wine by Philip Wagner
    Published in 1976, the book is dated, but the fundamental advice is sound. Available from Amazon.com
  • Techniques in Home Winemaking by Daniel Pambianchi
    A comprehensive introduction to home winemaking, this up-to-date book is very readable and has a number of tables to help the home winemaker. Available from Amazon.com.
  • The Wine Anorak – Online Wine Magazine
    From London – see what they are doing on the other side of the pond. A very comprehensive webzine, updated regularly. www.wineanorak.com
  • The Home Winemakers Manual by Lum Eisenman
    The most astonishing free book on winemaking you’ll ever find. This guy has written a 170 page treatise on home winemaking that you can download and print out. Read this, and absorb it, and you’ll be well on your way to being an expert home winemaker. Here’s
    a link, but many places have cached this… search on his name
    www.geocities.com/lumeisenman

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