Water Volume, Batch size etc.

[Craigerrr]

I have been working on a Double IPA recipe, and am wondering why entering water volumes just seem to be arbitrary entered amounts. For instance, I choose my batch size, and specify kettle or fermenter. I then look at the quick water requirements, and enter my mash volumes. Again, these are arbitrary numbers that don't affect the recipe. As an example I entered 20 gallons for kicks. The ion report is adjusted for the stupid amount of water I entered, but the rest of the stats, ABV, IBU, SRM, OG, etc, are not affected. For the software to be more accurate, would it make sense for the mash water entered to dictate the boil volume batch size etc? I liken it to entering a crazy stupid amount of hops, but having the IBU's set as an arbitray number by me.
https://www.brewersfriend.com/homebrew/recipe/view/934364/pg-dipa

 

[Pricelessbrewing]

Coincidentally, we're having a thorough discussion right now regarding some changes to how the mash guidelines, and volumes behave, as well as some other relevant changes. When/if these proposals go into beta, I'll make sure to tag you, and followup in this thread as well.

At the moment the recipe stats (og, ibu, srm, etc) are only affected by the preboil, postboil, and batch size. The mash guidelines have no impact on the efficiency, and therefore on the recipe stats. I do not foresee this changing in the foreseeable future, as it would require a change from the brewhouse/kettle efficiency driven model to the predicted efficiency model (like the one I use).

However there may be changes to how the preboil and postboil volumes behave, and more closely tie together the mash guidelines, the recipe, and the equipment profile.

As far as the quick water requirements, the only thing it does as far as I'm aware is calculate the expected volumes for a simple single infusion mash based on the amount of grain, the target volume, and the equipment profile. It is completely separate from what's actually entered into the mash guidelines.