between various units of density. Some conversions are not
perfect, for example specific gravity and °Brix do not measure the same
physical property, and are often measured using different instruments.
Some of these conversion are therefore based on expressions
derived from polynomial fits to experimental data sets. Potential alcohol
is not a measure of density, but it is useful. This calculation
is an approximation, for more detailed alcohol prediction see the alcohol prediction calculator. Dissolved Solids
is not a measure of density, but is useful. This is an estimate
of dissolved solids assuming that most of the solids are sucrose - it
will be close to the true value.
Details: This calculation is based on the method proposed by Duncan and Acton (Progressive Winemaking).
The calculation is based on the initial and final gravity.
The correction for DSOS is the the assumed gravity contribution
from Dissolved Solids Other than Sugar. The correction for DSOS
is hard to judge, but a suggestion is to use pre-ferment figures from
wines for which you know the final alcohol, and tweak the DSOS until
the calculation gives the correct value, then use the calculator for
making predictions for similar musts (variety, region, condition etc).
calculator will calculate alcohol by volume from the spirit indication
procedure. This procedure involves taking a sample of known volume and
making a hydrometer reading. The sample is then boiled until it
is reduced to about half its initial volume, topped up to the initial
volume again with distilled water (or any water giving a hydrometer
reading of 0.000), and a final reading is taken.
This calculator includes hydrometer temperature correction so it is not
essential to ensure the initial and final readings are made at the same
temperature, however the temperatures, and calibration temperature of the
hydrometer must be known.
Note: This procedure, if performed carefully, will
provide accurate results in wines regardless of residual sugar.
calculator uses a refractometer and hydrometer reading to ascertain the
alcohol content of the sample. The gravity measurement must be
from a hydrometer, and the °Brix measurement must be from a
refractometer, these values must not have been calculated from one
source. Alcohol (ethanol) has a higher refractive index than water, so a dry wine will usually give a refractometer reading in the range 5 to 15°Brix.
the progress of a ferment without having to take large samples and use
a hydrometer, simply take a small refractometer sample. Entering the
initial °Brix reading (pre-ferment) and the current reading will give
is all that is required.
Important: There are a
lot of approximations involved in this calculator. While this
method is extremely useful for monitoring ferments, and on the whole
quite accurate, it is not perfect - for example, do not expect it to
show a true °Brix of exactly zero when the fermentation has finished.
Details: A sample
of high sugar juice can be diluted in order that it can be read on equipment with
a limited scale. However because the °Brix scale is calibrated as %w/w, but
the dilution is carried out by measuring volume, the reading cannot simply be multiplied by
the dilution to obtain the °Brix of the juice. This calculator corrects for this, allowing
such dilutions to be used.
Note on SG: If measuring a juice using SG (specific gravity),
simple multiplication is possible. For example, a sample diluted to 50% with distilled water, which reads
1.090, has a gravity of 1.180.
density of water changes predictably with temperature and so it is
possible (and important) to correct readings taken at temperatures the
hydrometer is not calibrated for. Most hydrometers are calibrated
to 20°C, but some are calibrated to 15°C - any good hydrometer will
have the calibration temperature marked. This calculator, when
working with a hydrometer calibrated to 20°C, is accurate over the
approximate range 0-60°C, and when calibrated to 15°C, approximately
Details: This calculator will calculate the level of molecular SO2 in a wine based on its pH and measured free SO2 (the proportion of the measured free SO2 which is in the molecular form is dependant on pH). The required level of molecular SO2
for antimicrobial protection is often given as 0.8mg/L, although
sometimes up to 1.5mg/L (Wine Science - Ronald S. Jackson - 2008).
Red Wines: In red wines, most of the 'free' SO2
is actually pigment (anthocyanin) bound, and is released by
acidification of the sample prior to measurement. Due to this, it
is not currently possible to ascertain the level of molecular SO2
in red wines. Red wines are however, generally far more
microbially stable than whites, and thus are typically maintained at
lower levels of 'free' SO2. In summary, maintaining high molecular SO2 in red wines is difficult and ill advised - do not use this calculator as a guide for red wines.
calculation is based on the alcohol calculation from refractometer and
hydrometer readings. The alcohol is calculated and then used
together with the specific gravity to calculate the dissolved solids.
The gravity measurement must be from a hydrometer, and the °Brix
measurement must be from a refractometer, these values must not have
been calculated from one source. Alcohol has a higher density than water, so a dry wine will give a refractometer reading in the range 5 to 10°Brix.
Details: This calculator calculates the volume of wine to treat, and the mass of calcium carbonate (CaCO3) required to treat it for double salt deacidification.
The minimum volume to treat is the technically smallest volume of wine
which needs to be completely deacidified. Allowing slightly more
wine than this is the normal practice, as it ensures that the required
deacidification is completed. The recommended volume to treat is
simply 5% greater than the minimum, and is roughly in accordance with
the volumes provided by the makers of Acidex®.
** Calcium carbonate (CaCO3)
is the deacidification agent. Brand name agents such as Acidex®
consist almost entirely of calcium carbonate, but are seeded with
crystals of the double salt, calcium malate-tartrate, designed to
encourage precipitation of this salt. The mass calculated here
can be used in either case.
Tip: If you are
treating a small volume, enter 1000 times the volume you have and
the output will be in grams. For example, to deacidify 15 litres,
type 15000 and the mass output will be in grams.
DSOS: = Dissolved
Solids Other than Sugar - note that if your density reading is from a
hydrometer, using a value for DSOS is more important, if the reading is
from a refractometer, you can probably assume no DSOS.
calculator works out how much sugar to add to a given volume of wine to
raise it to a desired density (which we use as a measure of sugar
content). For convenience it also calculates the estimated
potential alcohol of the current must, and after the calculated
chaptalisation. The estimated finishing gravity and correction
for DSOS can be ignored if alcohol prediction is not required.
calculator calculates the point of fortification for making fortified wines
with residual grape-sugar (e.g. Port). It accounts for both the obscuration
of sugar, by the alcohol produced during fermentation, and the dilution of the
residual sugar, during fortification.
calculator works in the same way as a traditional Pearson's square. It
is used to give the volume of spirit (of known alcohol content) to add to a
volume of wine wine (of known alcohol content), to bring it to a desired
calculator makes fining trial and subsequent fining addition
calculations quick and simple. After performing fining trials and
deciding on an addition level, fill in all details and the volume of
fining agent required will be calculated. Be sure to check all units, the ones used here have been chosen for convenience in the majority of situations.
DAP = about 21% YAN (Yeast Assimilable Nitrogen) PMS = 57% SO2 by mass
calculator is for use with solids of which only a certain percentage is
active. From the percentage, the desired addition level, and the
volume of the juice/wine, the calculator will provide the mass of solid
calculator will calculate exactly how much of a solution of a given
concentration to add to a given volume of juice/wine, to reach a
desired concentration of the solute. For example, a solution of
concentration 500mg/L is to be added to 100L of wine to give the wine a
concentration of 10mg/L.
VinoCalc can not only be used on the internet, it can also be saved
for use without an internet connection. To save VinoCalc to your
computer, read the following instructions:
1 - Right click (for Mac users, hold control and click) on the 'Save VinoCalc' link below.
2 - In the menu that opens, select "Save As", "Save Link As", "Save Target As", "Download Linked File" or whatever command most approximates these.
3 - Choose somewhere to save the file 'vinocalc.html'
4 - You can now copy this file anywhere you want, to a USB stick, CD, other computers. When you want to use it, simply double click the file and it will open in your web browser, regardless of whether or not you have an internet connection.
Note: If you use VinoCalc offline, remember to check for updated versions from time to time.
Do this by opening VinoCalc, and clicking the link near the top of the page which reads "The latest version will always be available from www.musther.net/vinocalc.html". This link will take you to the online version of VinoCalc, the version number is in the top right of the page, if it is higher than the version you have, you can follow the above instructions to download the new version.
Gravity / Density
Every value is calculated from specific gravity. If another
value, such as Baume is provided, it is first converted to specific
gravity, and then all other values are calculated from that.
Calculating °Brix from SG is based on an expression from a polynomial
fit to a large data set:
Potential alcohol is calculated as discussed in the alcohol predicition
section, with the assumption of a final gravity of 1.000, and a
correction for DSOS of 0.007.
Oechsle has a simple relationship with SG:
oechsle = 1000 * (sg - 1.0)
Baume is also a simple relationship:
ba = 145 - (145 / sg)
Babo/KMW is also a simple relationship:
KMW = baume * 1.53
Grams per litre is obviously simply:
gl = 1000 * sg
Grams per litre of dissolved solids is calculated from the specific
gravity, and the °Brix. Subtly, these measure different things,
the specific gravity tells us the density of the liquid (grams per
litre) and the °Brix tells us the dissolved solids (percentage mass of
solute to solution - grams per 100 grams). This allows us to
calculate the dissolved solids, thus:
dissolved solids = gravity * (brix * 10)
The gravity tells us how much 1 litre of the liquid weighs (in kg) - we
then multiply this by the dissolved solids ratio to give dissolved
solids per litre. 'brix * 10' simply corrects the °Brix value
from being grams per 100 grams to being grams per kg. Thus, we
time number of kg in one litre, by the number of grams dissolved per
kg, and are left with the number of grams per litre.
To get from any of those values back to specific gravity involves a
rearrangement where possible. For °Brix to SG, another
expression was generated by polynomial analysis:
This calculator uses the same logic as in the 'Hydrometer Temperature Correction' calculator for correcting the readings for the temperatures at which they were taken. The difference between the initial and final gravities is then used to calculate the alcohol using the following formula:
abv = alcohol by volume
cg = current specific gravity
cb = current Brix reading (refractometer) NOTE The 0.93 conversion factor was added based on experimental results to make the alcohol prediction for this particular calculator more accurate.
The residual sugar (in grams per litre) is calculated thus:
residual sugar = specific gravity * true brix
Spirit indication is calculated form the current alcohol thus, and used to adjust the current gravity, so that true Brix and residual sugar can be established:
Note that this alcohol calculation is different than the one used in the alcohol by refractometer and hydrometer as it gives more reliable results when coupled with the other calculations used to monitor fermentation using a refractometer.
Monitor Ferment Progress with Hydrometer:
This calculator uses an assumption of the efficiency of alcohol production to calculate the 'true' Brix from the fall in Brix observed with a hydrometer. The derrived formula is:
True-Brix = ( 97 * i + 1200 * h ) / 1297
i = initial Brix
h = current Brix (from hydrometer)
The above formula is derrived from the more easily understood:
The calculations involved in this calculator are the same as those used in the gravity/density/sugar conversions. First the measured °Brix is used to calculate the gravity, which is then combined with the °Brix to calculate the dissolved solids. The dissolved solids is multiplied by (100/d), where d is the dilution percentage. So a dilution of 50% would mean multiplying the dissolved solids by 2. This number is then converted back to °Brix.
Hydrometer Temperature Correction:
The hydrometer temperatre correction for SG is performed with this expression:
correction = is the correction factor, added to the observed °Brix
temp = is the temperature difference from calibration (that is, reading temperature - calibration temperature)
apb = is the apparent °Brix, as read on the hydrometer
SO2 Aspiration/Oxidation Method:
The following formula is used:
SO2 = ( t * m * 1.6 * 1000 * 20) / v
m = molarity of NaOH
t = titre of NaOH required (mL)
v = volume of sample used (mL)
Calculate Molecular SO2:
The following formula is used to calculate the molecular SO2 from the free SO2 and the wine pH:
Molecular SO2 = FSO2 / ( 1 + 10( pH - 1.81 ) )
FSO2 = Free SO2
pH = pH of the wine sample
The formula is then rearranged to calculate the required level of free SO2 to achieve a desired level of molecular SO2:
Free SO2 = MSO2 * ( 1 + 10( pH - 1.81 ) )
MSO2 = Molecular SO2
pH = pH of the wine sample
The following formula is used:
ta = ( t * m * 75 ) / v
m = molarity of NaOH
t = titre of NaOH required (mL)
v = volume of sample used (mL)
Calculate Dissolved Solids:
Initially the alcohol is calculated in the same way as for the
'Alcohol from Hydrometer & Refractometer', and then the following
formula is used to calculate the dissolved solids:
ds = ( ( s * 1000 ) - 1000 + a * 1.264 ) * 2.52
s = specific gravity
a = alcohol, percent by volume
Simple deacidification is straight forward to calculate.
Firstly, the difference between the current TA and the target TA
is obtained, giving us the number of grams per litre we need to remove,
this is then multiplied by the number of litres, to give the total
number of grams of tartaric acid to remove.
As the deacidification agents used here react with tartaric acid in a
1:1 stoichiometric ratio, the factor to convert between grams of
tartaric acid and grams of neutralising agent can be found by dividing
the molecular mass of the agent by the molecular mass of tartaric acid.
Thus, the overall formula is:
mass of agent (g) = ( ( current TA - Target TA ) * vol ) * (Mr agent / Mr tartaric acid)
Mr = molecular mass
150.087 = Mr of tartaric acid
100.087 = Mr of calcium carbonate
138.2055 = Mr of potassium carbonate
100.11 = Mr of potassium bicarbonate
Double Salt Deacidification:
Double salt deacidification is somewhat more complex than simple
deacidification. A portion of juice is removed and completely
deacidified, that is, unlike with simple deacidification, tartaric and malic acid are removed. This portion is then blended back to the bulk of the wine to have the desired effect.
The volume to treat is calculated with the following formula:
volume (L) = ( ( current TA - target TA ) * total volume ) / current TA
The recommended volume to treat is this minimum technical volume multiplied by 1.05.
The following formula is then used to calculate the mass of calcium carbonate (or Acidex® etc):
mass (kg) = ( ( current TA - target TA ) * total volume ) * ( ( 1 / 150.087 ) / 10 )
150.087 = the molecular mass of tartaric acid
10 = is simply a conversion to make the mass express in kg
The alcohol calculation carried out here is identical to
that carried out in the 'Alcohol Prediction (pre-ferment)' section.
The chaptalisation calculation is based on calculation of dissolved
solids (grams per litre) as discussed in the 'Gravity/Density/Sugar
Conversions' section. The difference between the desired and the
current values is then simply multiplied by the number of litres to be
This calculator finds the fortification point for making fortified wines which contain residual grape-sugar, such as Port. The formulae are derrived from the following:
This is an accurate calculation as the volume being divided by is the
volume of wine AND the volume of the addition. This is often
overlooked in calculations such as these, especially when performing
them by hand. It is an important point to make, calculations
from this equation will differ from quick calculations by hand.
The next calculation is to find how much of a solution of a specified
concentration must be added to bring the concentration of the
juice/wine to a desired concentration, this is discussed in the
'Additions in Solution' section.
Note that this calculation takes into account the volume of the
solution being added, so rather than adding 1L of 100mg/L additive to
100L of wine to give the wine a concentration of 1mg/L, the calculation
shows that we need to add 1.010L.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.