Author Topic: IBUs don't match Promash values  (Read 3358 times)

Offline mbernhardt

  • BeerSmith Apprentice Brewer
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  • Posts: 4
IBUs don't match Promash values
« on: September 28, 2011, 11:39:46 PM »
I know this  topic has been sort of covered before but I'm not really seeing a clear answer: I have a friend's Promash recipe, which indicates a predicted IBU of 20. When I put that same recipe into Beersmith it predicts 17.2. They both use Rager and have 10% adjustment for pellets. They both have a 6 gallon batch. I've noticed this with other Promash recipes as well. And since I want my Beersmith recipe values to match the one I'm importing, this is a problem...

Why the difference and what can I do about it?

maddspoiler

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Re: IBUs don't match Promash values
« Reply #1 on: September 29, 2011, 07:56:16 AM »
Either there is a factor in the equation used that is different or the default alpha acids are set different or the hop utilization factors on the programs are different from each other.

 
If its the default values~
When you input the recipe in Beersmith did you change the alpha acid content to match the Promash Recipe? I know each program has its own set of default values and usually when I buy hops they arent exactly what the programs say and I have to adjust (this could also change the IBUS in the batch being brewed). Might be something as simple as that. One might list Cascade at 5.5% aau and the other program might say its 6% aau (as an example). I suggest you check this first.

If its Hops Utilization factor you can change that in your equipment profile to what pro mash says it is in the recipe you want to copy (if thats what you want to do).

But like I said the formulas might be a little different.

What I would do is just brew and see how it turns out. Then adjust according to how I want it to turn out and my brewhouse efficiency/equipment profile etc etc.

Offline mbernhardt

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  • Posts: 4
Re: IBUs don't match Promash values
« Reply #2 on: September 29, 2011, 08:20:43 AM »
I did check the alpha acid content already and that didn't do it (in fact, Promash has LOWER values for the hops in this recipe). I don't know what the default hop utilization is in Promash, but if I set it in my equipment profile to 107%, it works out just right.

I'd be curious if this has been an issue for others and what they did about it.
« Last Edit: September 29, 2011, 08:37:22 AM by mbernhardt »

maddspoiler

  • Guest
Re: IBUs don't match Promash values
« Reply #3 on: September 29, 2011, 01:58:43 PM »
It must be the way it calculates it then... I would just choose to brew and see how it tastes compared to your buddies then make adjustments from there. I would look at it like comparing Tinseth to Rager. Just choose one and stick to it and youll eventually figure out what 40IBUS should taste like reguardless of the formula used. Good Luck.

 

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