Est OG versus Est ABV

I have noted in my recipe designs that for a given style BS2 estimates OG at the high end of the spectrum, versus ABV usually much lower (I am referring to the positioning of the slider in the color coded style spectrum). I don't manage to adjust the grain profile to be smack in the middle for BOTH OG and ABV.

Can anybody tell me why that is? I have attached a current recipe, an Imperial IPA, where I wonder why OG is so high, while ABV is in the middle.

Thanks, Jurgen

OG and ABV are dependent on different factors thus they may not always track one another.

Your OG depends largely on the amount of grain in a given batch, among many other factors. How fast it moves up or down that sliding scale is a function of the fermentability of the sugars in the resulting wort. To see this in action, add a pound of sugar to your recipe and see how much faster the ABV slider moves relative to the OG slider.

The ABV is determined by the fermentability of the wort and also by the yeast's ability to attenuate. WY1272 is a pretty good attenuator, and your present mash schedule shows a mash-in at 152 F with a grain bill that is 90% base malt which should give you pretty good fermentability, and assuming conversion was good and the fermentation goes well, you should arrive at your predetermined ABV. Sometimes you can coax a little more than the rated attenuation out of a yeast strain with the right fermentation conditions.

Knowing what effects OG and ABV, you can see they will not always move in lock-step.

As an aside; those sliders are merely ranges set by the style guidelines, and it is not necessary to always stay within the margins - that's the fun of homebrewing - drawing outside the lines can produce some amazing brews!