The calculator assumes that no lautering is done after mashing. It is therefore more suitable for Bourbon than for Malt Whisky.
Instead of %, simple ratios can be entered. For example, 3 for corn and 1 for barley means three times as much corn as barley.
The calculated values are realistic, but require a good mashing technique. The calculator assumes that 85% of the starch is converted into fermentable sugar. This value can be changed at the slider at the top.
However, this mash efficiency does not apply to entries in the "Sugar" line. With sugar, all carbohydrates are fermentable.
And the calculator assumes a quite complete fermentation. This means good conditions for the yeast. Above all, the sugar content or the targeted alcohol content must not be higher than the yeast can tolerate. So although you can calculate an alcohol content of 30%abv with the calculator, but of course this is not possible in practice.
If the measured value after fermentation is higher than calculated here, the calculated alcohol content has not been reached.
During the conversion of starch into fermentable sugars by malt enzymes, mainly maltose and significantly less glucose is produced. Fructose and sucrose are produced only in very small quantities. The calculator assumes 80% maltose and 20% glucose. This ratio can be changed at the slider at the top.
If you mash with added enzymes instead of malt, almost only glucose is produced. Then you should set the slider to 100% glucose. And if you mash with malt, but with added enzymes, a mean value, perhaps 70% glucose. It doesn't matter much, but it might be interesting: you can see that with added enzymes you get a slightly higher SG reading, but that doesn't then lead to a higher alcohol yield. So if you have a slightly higher reading after mashing due to added enzymes than you would otherwise, it is not necessarily due to higher sugar yield, i.e. higher mashing efficiency, but at least partly simply because glucose solutions have a higher density than maltose solutions.
The default values for the unmalted grains are from naehrwertrechner.de. For malted grains, we did not find values directly compatible with the data of unmalted grains. The main difference in terms of nutrients is that in malted grains, the water content is much lower and thus the starch content is higher. And since the germ removed during malting is very high in protein, and protein makes up a relatively large portion of the unfermentable matter, malted grain has somewhat less unfermentable matter compared to carbohydrates than unmalted.
If you have your own values for the grain you are using, or even if you want to blend completely different grains, you can change the % Carbohydrates and % Water entries. The % unfermentable substances, i.e. the value at which the % carbohydrates and % water add up to 100%, are calculated from this.
These unfermentable substances have a high density. The calculator assumes 1.5kg/lt. This value can also be changed:
Density of unfermentable substances:  kg/lt
The unfermentable substances in cereals are mainly fibers and proteins, but also some fats and minerals.
It is possible to switch between SG, Oechsle, kg/lt density, Brix and Plato. The calculated reading after fermentation refers exclusively to a density meter. A refractometer shows a much higher value after fermentation.