Why does adjusting the length of Boil not change the OG?

[Jeremiah White]

Seems like a very obvious feature to not have. Can anyone explain why this does not work?

 

[Ozarks Mountain Brewery]

I think it should do that plus change the color darker

 

[Jeremiah White]

Agreed, and nice recipes man.

 

[Yooper]

That's a good question! I assume it is because not changing the beginning volume and the ending volume in the recipe means the same OG(?) but I will check into this.

Normally, if I do a 90 minute boil, I raise my starting volume due to the increased boil off. But that doesn't change the actual SG if I end up with the same volume as on the recipe.

 

[Ozarks Mountain Brewery]

yes I do the same thing but in the software, the time you boil doesn't change anything and it should, say you don't change your recipe and boil for 120 minutes, nothing changes in the software. it should darken the srm and increase the og, I know this is a bit tricky to calculate but it should make a difference

 

[Yooper]

Isn't that true of all software?

If you just lengthen the boil, and don't change any other parameters, the OG wouldn't change (since you'd have to either start with a larger volume or end with a smaller volume in order to get that to change), and the maillard reactions wouldn't make it much darker unless the volume was reduced. I hope that makes sense.

Now, if you start with 8 gallons, and boil for 120 minutes down to 5 gallons, then yes, the OG would change and so would the color. If you input that into the software, it should give you the changes you would expect.

 

[J A]

Ideally, changing the boil time should change the batch size (post boil) or boil size according to your preference. There would have to be a parameter set in the profile to choose which variable you intend to change.
Larger pre-boil changes wort gravity and affects hop uptake and post boil batch size changes OG and color. Since the interface/choice doesn't exist in the software, just changing the batch size manually to reflect the proper post-boil or pre-boil amount will change everything accordingly.
Since I use batch size as a (relative) constant, I sparge more and change pre-boil to account for more boil off. Since I don't add hops until 60 minutes, I estimate the wort volume at that point in the boil to see how much the IBUs will deviate. It's never much if the boil is 75 or 90 minutes, maybe a point or two.
It would be kind of cool to incorporate that chain of events in the boil time, but maybe there are too many possible combinations to easily account for.

 

[Ozarks Mountain Brewery]

what Ive found for me, nothing really goes exactly as planed, many things change along the way on brew day, some are just slight changes and thats because I don't brew based on time, I brew based on amounts and every brew day is different because of that. so the software really cant keep up with me as im brewing because of minor changes so I have to just use the recipe as a guide not as fact, most of the time its very close if not right on anyway as far as final gravity, mouth feel and alcohol levels, the rest isn't as important to me. the only thing thats never correct is the final SRM in my beers, most are darker for some reason but not important like i said