# Brew Software to account for top up water



## Bomber Rock (2/2/18)

Hi all,

I have tried a bunch of apps, but they all seem to have the same limitation. See Im a relatively new BIABer on a Crown Urn (less than 5 brews). Wort is no chilled into a 17L cube. When I transfer to the fermenter, I add 5L to make up to 22L.

Does anyone know of a software that you can tell it that you want to brew 17L, then make up to 22L later? I want it to be able to tell me how much water I need on brew day, but then work out my SG, IBU etc after dilution. Preferable to be able to use in pc, mac, ios and Android.

If such a beast doesn't exist, what do you all do to get around this issue?


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## MHB (2/2/18)

Say you want 22L in the fermenter, your 17L has to be proportionally stronger
Using the short form of the dilution equation C1V1=C2V2
Where V is a Volume in the same unit (i.e. Litres)
and C are a Condition (i.e. SG) *NB* you cant use 1.050 for example as that isn't unitary, use 12.5oPlato, or 0.050 or the point system 50 points.
Plug it all into your equation. Lets say you want 22L at 1.050 after dilution
0.050*22=x*17
(0.050*22)/17=x Target OG would be 0.0647, call it 0.065 or 1.065

Design your recipe to make 17L of 1.065 wort and just add the 5L to the fermenter
Mark


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## Mayor of Mildura (2/2/18)

Beersmith does this. You need to setup an equipment profile and away you go.


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## Dazza88 (2/2/18)

MHB is right and is telling to use a ratio to scale up to 22L from 17L. 

You could consider a desired OG of 1. 050 as "50" for desired OG in the equation below.

For your situation: 22/17 x desired OG = OG required in your urn

E.g 22/17 x 50 = 64.7 (i.e. gravity 1.0647 required in your 17L of wort in the kettle).


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## Mayor of Mildura (2/2/18)

How do you calculate IBU? What about hop utilisation?


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## MHB (2/2/18)

Same way, you know how many IBU you want after dilution - say 45IBU in 22L, using the same equation
45*22=17*x, (45*22)/17=new IBU target 58.23.
Utilisation would then be implicit in the calculation for making 17L of 58IBU beer

It really is a very useful little equation.
Mark


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## Mayor of Mildura (2/2/18)

Interesting. But i'm a simpleton and prefer less algebra on brewday. I'll stick to beersmith.


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## Dazza88 (2/2/18)

Fair enough to use software but as MHB said its exactly the same scaling up. For the OP:

22/17 x desired IBU = IBU required in kettle.


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## Bomber Rock (2/2/18)

Cool. Thanks for the responses. I understand the maths and, in fact, I don't even need to work it out myself. I currently set my fermenter volume as 17L on Ian's BIAB spreadsheet for my pre diluted info, then change the fermenter volume to 22L for the diluted info and I have all I need.

Nevertheless, I will trial beersmith as that seems to be the no 1 brewing software and it does what I'm after.


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## Danscraftbeer (3/2/18)

Mayor of Mildura said:


> Interesting. But i'm a simpleton and prefer less algebra on brewday. I'll stick to beersmith.


This!
You simply change the batch volume from 17l to 22lt and Beersmith recalculates it all.


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