Alcohol Gauging and Blending Calculations
We are currently developing a sister product to AlcoDens which will perform most of the calculations that AlcoDens does for mixtures of potable alcohol and water, but with sugar added into the mix. This page will be used to keep interested distillers informed of the progress made so far, and to give an outline of the sections still to be written. If you would like us to notify you when the trial version is available for download please write to us giving your name and email address, and ideally including some comments on what other functions you would like to see built into the program.
There are no official tables of alcohol Volume % (ABV) or Proof vs Density data for the ethanol/water/sugar system like the TTB and OIML Tables that exist for ethanol/water mixtures. This has necessitated producers of liqueurs containing sugar to rely on various inaccurate rules of thumb, which result in trial and error blending and repeated laboratory determinations of the sugar concentration and the alcohol Volume % (ABV) or Proof in the product. Over the years many users of AlcoDens have requested us to add the ability to include sugar in proofing calculations, but the problem was always the availability of sufficient good quality Volume % (ABV) or Proof vs Density data. We have been collecting this data continuously since the requests first started coming in and eventually reached the point where we had sufficient confidence in the data to start work on this project.
Our plan for the first release of AlcoDens LQ is that in addition to all the calculators included in the standard AlcoDens it will also have calculators available for the following three functions:
As of October 19, 2016 all three calculators are completed and working well, and work is underway on writing up the Help system and doing the final testing. The sections below give descriptions of the completed calculators with examples of typical calculations. If you have any queries on what you see here you are welcome to write to us for further details.
(Edit: February 15, 2017) Several distillers have very generously given their help and advice during the development process, and one item which they highlighted was the need to be able to adjust the alcohol to the target level without targeting a sugar level at the same time. We have added in the ability to target only the alcohol while letting the sugar find its own level. This is useful when the alcohol and sugar levels are close to the target, but a final tweak is required to the alcohol to meet excise requirements. The blending examples given below have been extended to show this as well. Our apologies to all those who have been waiting for the release of the software as this has caused delays.
Although the blending calculator is not difficult to use, in order to provide the necessary flexibility it does have a lot of settings and inputs. This makes it look rather complex at first sight, but you will soon see that many of the settings are the same for several of the raw materials and as soon as you have mastered one of the sub-panels you will also understand the others.
The calculator has two modes of operation. It can either be used to calculate the ingredients to make a specified quantity of product, or it can be used to calculate what additional ingredients must be added to a specified quantity of base liqueur to correct the alcohol and sugar levels. Examples of both of these calculations are given below.
When applicable, an entire panel can be switched off to simplify the look of the calculator. And the input fields for any data that is not required for a specific calculation will be hidden.
As an example, we will calculate what raw materials are necessary to make 100 US gallons of liqueur at 65 proof and 250 g/liter of sugar (measured at 60°F). There is no base liqueur available and that panel is switched off (see image below). There is syrup available at 60 Bx and spirit at 95 ABV (measured at 20°C). A flavoring agent will be added at 1% of the total product mass. The flavor contains 25% ABV and a sugar loading of 155 g/liter (both measured at 20°C). All raw materials will be added by mass.
Anyone who has done this sort of calculation before will immediately see that there are an infinite number of ways in which these raw materials can be combined to make the desired product. The AlcoDens LQ liqueur blending calculator therefore needs some heuristic rules to guide it. There are 2 rules embedded into the calculator to ensure it gives the optimum answer. These rules are:
Both of these rules can be modified slightly by the user by either turning off the availability completely or by setting limits on the amount of base liqueur or syrup available.
The calculation as performed by AlcoDens LQ is shown below.
Note that although the target quantity of product was set in volumetric terms (100 gallons) the user is able to choose whether to measure most of the raw materials by mass or volume - only the flavoring and any dry sugar required must be measured by mass.
Having made up the liqueur using these quantities, having mixed it thoroughly and left it to settle overnight we take a sample and confidently take it to the lab for analysis. Much to our surprise the lab reports that the proof is 69.03 and the sugar loading is 242.5 g/liter (against the target values of 65 and 250 respectively). A bit of checking shows us that the total mass is 408.675 kg instead of the expected 398.675 kg and we start to suspect a problem in the raw material quantities. A close examination of the log sheet shows that Igor added 114.61 kg of spirit instead of 104.61 kg.
So the proof is too high and the sugar loading is too low. What must we add to get to the target values, with the minumum of extra raw materials? This is exactly the problem AlcoDens LQ is designed to solve. We change the target quantity option in the top right panel from product to base liqueur and this automatically turns the base liqueur panel back on. We key in the proof and sugar loadings given by the lab for the base liqueur and turn off the flavoring panel because we need to add additional flavoring only in proportion to the extra ingredients that will be added. If necessary, once we have calculated the new total product mass we can come back and calculate a bit more flavoring.
The specifications for the syrup, spirit and product remain exactly as before and the additional quantities of syrup and water required are calculated and shown in the source quantities panel. The product quantities panel shows that we will get approximately 10% more product than we were originally targeting. This is not surprising since Igor added roughly 10% more spirit than he should have. The final calculation is shown below.
AlcoDens LQ has calculated the minimum quantities of additional ingredients required to correct the proof and sugar loading to the original target. This minimization is ensured through the application of Rule 1 given above.
A late change to the AlcoDens LQ specification, which has unfortunately delayed the release of the software, has been the ability to adjust only the alcohol level of a Base Liqueur while allowing the sugar to find its own level. This is useful when the alcohol and sugar levels are close to their targets, but a final tweak is required to the alcohol to meet excise requirements. In this situation only Spirit or Water will be added and no further Syrup or Granular Sugar is allowed.
In the example above we corrected the Base Liqueur to the orignal targets of 65 Proof and 250 g/liter sugar, but now we will recalculate it so that the Proof can be adjusted from 69.03 to 65.00 while ignoring the sugar level. An interesting point to note in comparing the options with and without additional sugar is that in both cases the volume of liqueur finishes up exactly the same (109.485 US gallons). This is because the Proof needed to be adjusted downwards, so no additional alcohol would be added. All the alcohol was already in the Base Liqueur and since the Proof is set at 65.0 in both cases having a fixed quantity of alcohol resulted in a fixed volume.
In the Options panel in the top right corner the Product Target has been set to "Alcohol only". The means that the Product Sugar Loading will find its own level. In this case the sugar loading has turned out to be 228.343 g/liter. This will give the distiller an indication of whether the taste will vary enough to justify adjusting the sugar as well.
Several different ways are used to express the concentration of sugar and ethanol in liqueurs. The choice of which way to express the concentration will depend on the local legislation and on the purpose for which the concentration will be used. This calculator will convert between any two pairs of concentrations for sugar and ethanol simultaneously.
For example, sugar loadings are often specified in Mass per Volume terms such as gram/liter or mg/100ml, but it is easier to measure out and add the sugar in Mass per Mass terms such as Weight % or Brix. Similarly, regulations for alcohol content are usually given in Volume % (ABV) or Proof but it is more accurate to measure the spirit and liqueur product in mass terms.
Any given combination of ethanol, sugar and water concentrations will have a unique density (at a specific temperature), so this calculator is also able to convert between density and concentration. This makes the calculator very useful for checking the consistency of laboratory results, or even to predict unmeasured concentrations.
A typical laboratory analysis for process control (and to meet tax regulations) would involve measuring the density (or SG) of the liqueur, as well as its sugar content and alcohol Volume % (ABV) or Proof. This calculator will quickly check whether the 3 measured values are consistent with each other. Or if only two of these parameters are measured it will give a rapid indication of the third value. So if you have accurately weighed out your spirit and sugar you will know the sugar content on a mass basis, and measuring the density of the liqueur will immediately allow you to calculate the alcohol content in Mass %, ABV or Proof terms.
On the calculator shown below, you simply select the values that you know as the "From" options and select the values you want to convert to as the "To" options. If the conversion that you have selected requires the temperature then the program will request you to enter that as well. The units for the input and calculated values are set, the input values entered, and the answers are calculated automatically. If the conversion requested is impossible then an error message will be shown in the Status Bar at the bottom of the calculator.
In this example knowing that the sugar loading is 10.006 Mass % and that the liqueur density is 1.01679 SG enables us to calculate that the ethanol strength is 13.87 Mass %. The ethanol strength could be expressed in Volume % or Proof terms simply by selecting that option in the "To" column of the Ethanol Strength panel. The calculator has also converted the sugar loading into g/liter terms for us.
With a mixture consisting only of alcohol and water we can use an hydrometer and a thermometer to determine the concentration of the spirit, usually in Volume % (ABV) or Proof terms. This is because at any given temperature there is only one combination of ethanol and water concentrations that will result in the specified density.
However, when we have sugar in the mixture then the hydrometer and thermometer readings are not sufficient to determine all the concentrations. This is because there are many combinations of ethanol and sugar concentrations that will result in any given density. But if we know the sugar concentration from some other measurement method we can use the hydrometer and thermometer to determine the ethanol concentration. Or conversely, if we know the ethanol Volume % (ABV) or Proof we can use the hydrometer and thermometer to determine the sugar loading. It is therefore still useful to have an hydrometer temperature correction calculator for use with liqueurs.
When pure ethanol is added to a liqueur the density decreases, but adding sugar to the liqueur will increase the density. These opposing effects are known as "Proof Obscuration" because the sugar hides or masks the usual decrease in density caused by increased ethanol. Section 30.32 of the TTB Gauging Manual stipulates that for solid contents between 400 and 600 mg/100ml the proof can be calculated by adding 0.4 proof for each 100 mg/100ml. This applies only to spirits in the range of 80 to 100 proof, and the maximum value of 600 mg/100ml (or 6 g/liter) is much less sugar than is usually used in liqueurs so this rule of thumb is not helpful in gauging the Volume % (ABV) or Proof of liqueurs.
The example shown below illustrates how inaccurate this rule of thumb is when working with liqueurs. In this case we have a spirit containing 150 g/liter (15000 mg/100ml) of sugar with an apparent proof of 10. By calculating the concentrations rigorously the true proof is found to be 94.66. In this case the obscuration is 84.66 proof, or (84.66/150 = ) 0.564 proof per 100 mg/100ml. This is why the TTB requires proof determination to be done by laboratory bench scale distillation when the solids content exceeds 600 mg/100ml. Running a bench distillation to determine the true Volume % (ABV) or Proof after every blending adjustment takes time and consumes product. This makes it far better to simply measure the solids content by the usual evaporation method and measure the liqueur density with an hydrometer, and finally determine the proof by calculation as shown here for each blending operation. The final verification of the Proof will have to be done by distillation if you work under the jurisdiction of the TTB.
This example shows that when the sugar loading is high the rule of thumb that each 100 mg/100ml of solids obscures 0.4 proof is no longer valid. Here the obscuration is (94.66 - 10.00 =) 84.66 proof and the ratio is 84.66/150 = 0.564 proof for each 100 mg/100ml.
AlcoDens LQ is not available for purchase yet. Anyone who has purchased the standard AlcoDens in the past, or who purchases it before (or after) AlcoDens LQ is released will be able to upgrade their AlcoDens license to AlcoDens LQ for the difference in price plus a small handling fee.