Author Topic: Boiling Volume changes don't change IBUs  (Read 3519 times)

Offline rctazz

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Boiling Volume changes don't change IBUs
« on: April 28, 2014, 06:51:55 PM »
Hi,  new to the forum.   I downloaded the trial version of Beersmith 2.   Trying to adjust HOP addition for a full boil.  When put in all of the Hops,  I get a bitterness value.  When I change the Boil volume doesn't change the bitterness value at all.   That goes for any method of calculation.   Is this a software issue or am I doing something wrong?

Thanks

Offline brewfun

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Re: Boiling Volume changes don't change IBUs
« Reply #1 on: April 30, 2014, 10:05:52 PM »
The formulas for bitterness are not unique to BeerSmith. They are widely used across the brewing spectrum. So, no; it isn't a software thing.

I would have to know by how much you're changing the boil size? And was this previously covered by top up water?

Your batch size plus loss to trub numbers determine the volume BeerSmith will calculate from. If the batch size isn't different, then the additional boil volume is not going to factor into the bitterness number.

Beer Appreciation is the space between pints.

Offline rctazz

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Re: Boiling Volume changes don't change IBUs
« Reply #2 on: May 04, 2014, 05:37:14 AM »
I have tried changing the boiling volume from 1.0 gallons all the way up to 10 gallons on the Hop Bitterness screen,  the IBU value does not change at all.   

With all other calculators I have used,  the IBU goes up as the boil volume number is raised with no other change of values to account for Hop Utilization.

Numbers I used on the HOP bitterness screen (IPA)
1 oz Summit  - 60 minute boil
1 oz Chinook  - 30 minute boil
1 oz Cascade  - 15 minute boil
1 oz Cascade  - 5 minute boil
1.064 initial gravity
Batch volume 5 gallons
Boil volume - started at 2.5 gallons and changed to 7 gallons.   No change

I am trying to scale a Kit's Hops to account for going from  partial boil of 2.5 gallons to full boil.

Offline brewfun

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Re: Boiling Volume changes don't change IBUs
« Reply #3 on: May 04, 2014, 08:53:47 AM »
1.064 initial gravity
Batch volume 5 gallons
Boil volume - started at 2.5 gallons and changed to 7 gallons.   No change

I am trying to scale a Kit's Hops to account for going from  partial boil of 2.5 gallons to full boil.

As long as batch volume and gravity remain constant, so will the IBU number. Boil volume is irrelevant. It's just water you boil off to achieve the batch volume.
Beer Appreciation is the space between pints.