With this calculator it is very easy to try out with a slider the effects of the length of a fraction on aroma compounds. So, for example, what effects it has to separate more or less foreshots. And this in a concrete situation, i.e. with a certain alcohol strength in the still and with a certain rectification.
First you enter the liter and %abv in the boiler and the number of theoretical plates. After pressing "Calculate", the distillation is calculated in 300000 small steps. This can take a few seconds. Especially if distillations with many theoretical plates are calculated.
After that the slider can be used and, depending on the slider position, the values in the boiler, in the vapor and in the distillate are displayed.
In the tables now the values of the different congeners are displayed. One can select whether one would like to get a small or a large fraction displayed. The small one includes at most the first 1/100 of the distillate content and is therefore suitable for calculations of the foreshots. The large one includes at most the whole distillation and is therefore suitable for larger fractions like the hearts or the tails.
And one can select whether the tables show the values before or after the cut (the slider position), that is, the values in the distillate or in the boiler. If you want to see the composition of the foreshots, for example, you will choose to display the values before the slider.
If you move the cursor over a congeners name without pressing (or tap on it in the case of a touchscreen), other names and also further information about this congener will be displayed.
The order of congeners within their congener group (for example "ester") depends on their molar mass. Generally speaking, within a group of congeners, the larger molecules are those with the better aroma or those from which the more interesting aromas can be created.
For each congener there is the column "% absolute". This shows the percentage in the selected fraction compared to the total amount of the congener. "100%" therefore means that all the congener that was in the boiler before distillation is now in the selected fraction. So, it is calculated regardless of how much of the congener is actually in the boiler.
For each congener there is also the column "% relative to ethanol". This compares the "% absolute" of the congener with the "% absolute" of ethanol, which allows conclusions to be drawn about the strength of the aroma, which is why these values have a higher significance than the absolute values. For example, if the fraction contains 10% of ethanol and 10% of the congener, 100% is displayed in the table field. If, on the other hand, only 5% of the congener is in the fraction, 50% is displayed, since 5% of 10% is 50%.
In three of the five congener groups, there is also a column with values relative to a substance other than ethanol. These allow conclusions to be drawn about the quality of the aroma.

More information about congeners and calculation examples
Information about our boiling point data