Hydrometer/Sugar/Alcohol Tables

©Copyright Ben Rotter 2004-2016
www.brsquared.org/wine

Specific Gravity, Brix, Baumé, Sugar, Potential Alcohol

Sugar

Excluding "PA" column 5, the data presented here for potential alcohol levels assumes no soluble solids other than fermentable sugar, and the fermentable sugar quoted is the quantity in the liquid for the required respective values. Accounting for non-sugar solutes (aside from "PA" in column 5) is left to the individual winemaker's discretion.

Sugar values themselves under the "Sugar" columns account for the volume changes incurred at the "ends of the scale". The values are taken from Progressive Winemaking (Duncan, P., and Acton, B., G.W.Kent Inc, 18th impression, 1991).

Potential Alcohol

The Potential Alcohol (PA) level listed assumes a must beginning at the SG given on that same row of the table and fermenting to dryness, i.e. it is the maximum potential alcohol assuming all sugar is fermented and no sugar additions are made after inoculation. PA values are calculated based on "SG"/"Brix" values, not on "Sugar" values.

The table below presents estimated alcohol using five different methods.

The actual quantity of alcohol produced is dependant on the individual yeast strain and fermentation environment. Some sugar is also used by the yeast for growth and production of other compounds, and some alcohol escapes with the carbon dioxide produced during fermentation. No method of estimation will be 100% accurate in predicting final alcohol content.


The theoretical yield of alcohol from sugar due to alcoholic fermentation (glucose is converted by yeast to ethanol and carbon dioxide) is 51.1% by weight (65 %/volume). However, with these considerations it is closer to 47% by weight (59 %/volume). Jackisch notes that for "red grapes from hot areas" the yield is closer to 43% by weight (54 %/volume) (Modern Winemaking by Philip Jackisch, Cornell University Press, 1985).

There are five Potential Alcohol (PA) columns given in the table below. The five columns use the following methods to calculate PA:

1. The first is commonly used in amatuer home winemaking books (PA = 0.6×Brix - 1).

2. The second is based on a formula given in Progressive Winemaking (Duncan, P. and Acton, B., G.W.Kent Inc, 18th impression, 1991). To estimate alcohol by volume, they suggest dividing the total gravity drop (must gravity minus final gavity) by a factor, F, that is calculated based on the gravity of the must, where the factor is defined as follows:

F = 7.75 - (3×G)/800
and G is equal to the gravity of the must.

They claim that values obtained with this method give values close to those of an ebullioscope and are within +/- 0.5% abv accuracy when final abv lies between 10% and 14%.
The abv values presented in the table below assume a final SG (FSG) of 0.996(gravity of -4).
3. The third method assumes an alcohol yield of 51.1% by weight of the sugar content of the must and is calculated based on the Brix value (%abv = Brix×0.59).

4. The fourth method assumes an alcohol yield of 43% by weight of the sugar content of the must and is calculated based on the Brix value (%abv = Brix×0.43).

5. The fifth methods accounts for 3 degrees Brix (0.021 degrees specific gravity) of non-sugar solutes and 51.1% by weight alcohol yield. This method has was advocated by UC Davis in the past.


Brix is calculated based on the relationship: Brix = 220×(SG - 1) + 1.6

SGGravityBrixBauméSugarSugar (lb&oz/US gal.) Sugar (lb&oz/Imp. gal.) PA 1 (%)PA 2 (%)PA 3 (%)PA 4 (%)PA 5 (%)
(degrees)(degrees)((SG - 1)×220) + 1.6g/llbozlboz0.6×Br - 1FSG = 0.996Br×0.59Br×0.54PA = ((Brix - 3)×SG)×0.59
1.00001.60.0401010.00.50.90.90.0
1.00552.70.71702030.61.21.61.50.0
1.010103.81.43004051.31.82.22.10.5
1.015154.92.14406071.92.52.92.61.1
1.020206.02.85708092.63.13.53.21.8
1.025257.13.570090113.33.84.23.82.5
1.030308.24.2830110133.94.54.84.43.2
1.035359.34.9970130164.65.15.55.03.8
1.0404010.45.6110015125.25.86.15.64.5
1.0454511.56.212310145.96.56.86.25.2
1.0505012.66.913612166.67.17.46.85.9
1.0555513.77.514914187.27.88.17.46.7
1.0606014.88.2163161107.98.58.78.07.4
1.0656515.98.8176171128.59.29.48.68.1
1.0707017.09.4189191149.29.910.09.28.8
1.0757518.110.1202111209.910.610.79.89.6
1.0808019.210.72151132210.511.311.310.410.3
1.0858520.311.32281142511.212.012.011.011.1
1.0909021.411.9242202711.812.712.611.611.8
1.0959522.512.5255222912.513.413.312.112.6
1.10010023.613.12682421113.214.113.912.713.4
1.10510524.713.72822621313.814.814.613.314.1
1.11011025.814.32952721514.515.515.213.914.9
1.11511526.914.9308293115.116.315.914.515.7
1.12012028.015.53212113315.817.016.515.116.5
1.12512529.116.03352133616.517.717.215.717.3
1.13013030.216.63482143817.118.517.816.318.1
1.13513531.317.13613031017.819.218.516.919.0
1.14014032.417.73743231218.419.919.117.519.8
1.14514533.518.33873431419.120.719.818.120.6
1.15015034.618.8401364019.821.420.418.721.4
1.15515535.719.4414374220.422.221.119.322.3
1.16016036.819.9427394421.122.921.719.923.1




Hydrometer Temperature Correction Table

For hydrometers calibrated at 20°C (68°F).
Temperature (°C) Correction Temperature (°C) Correction Temperature (°C) Correction
10 -2.0 21 0.2 32 2.4
11 -1.8 22 0.4 33 2.6
12 -1.6 23 0.6 34 2.8
13 -1.4 24 0.8 35 3.0
14 -1.2 25 1.0 36 3.2
15 -1.0 26 1.2 37 3.4
16 -0.8 27 1.4 38 3.6
17 -0.6 28 1.6 39 3.8
18 -0.4 29 1.8 40 4.0
19 -0.2 30 2.0 41 4.2
20 0.0 31 2.2 42 4.4


Correction (SG) = 0.2×Temperature - 4 (Temperature in degrees Celcius)
(According to Progressive Winemaking by P.Duncan & B.Acton.)
Correction (Brix) = 0.03×Temperature - 1.8 (Temperature in degrees Fahrenheit)
(According to Modern Winemaking by Philip Jackisch.)



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