Predicting IBU's

[NotionCommotion]

Hello,

I found some great formula's for predicting the hops IBU's (reference Tinseth and many others). Typically all the formulas take into acount weight of hops and alpha acid content, and then figure out a utilization based on time of boil and gravity of the boil. They then divide by the volume to get IBU's.

In regards to volume, should it be the final volume, or the final volume plus kettle loss volume plus fermentor loss volume?

Thanks

 

[Kaiser]

In regards to volume, should it be the final volume, or the final volume plus kettle loss volume plus fermentor loss volume?

The volume is the final volume in the boil kettle.

Kai

 

[frothy]

I'm having trouble with working out the kettle utilization - should I presume that its 100% for a 1hr boil? Could you guys recommend a site or some equations as I've noticed that there are a few different approaches.

thanks
Matt

 

[budbo]

I'm having trouble with working out the kettle utilization - should I presume that its 100% for a 1hr boil? Could you guys recommend a site or some equations as I've noticed that there are a few different approaches.
thanks
Matt

isn't it more like 30% for 60 min

 

[sonvolt]

I'm having trouble with working out the kettle utilization - should I presume that its 100% for a 1hr boil? Could you guys recommend a site or some equations as I've noticed that there are a few different approaches.

thanks
Matt

Here . . . check out this chart from John Palmer's book (scroll to the bottom of the page). http://www.howtobrew.com/section1/chapter5-5.html

Your utilization will be far less than 100%, but this is also dependent upon the gravity of your wort. For instance, if you are boiling hops for 60 minutes in a 1.050 wort, you will get 23% utilization.

 

[frothy]

Muchos Gracias