IBU's accuracy and elevation

by **curlyfat** » Tue Mar 24, 2009 4:19 am

Ok, here's my quandary: I use ProMash to formulate all my recipes. I always shoot for bitterness at the high end of what's acceptable for the style I'm brewing. However, I always end up with less bitterness than I expect (comparing to the rare craft brew that lists IBU's). I usually end up compensating with extra boiling hops, but wish I could be more accurate. I always keep my hops vacuum sealed and frozen. I wonder if elevation could be affecting it. I live around 6000 feet and my water boils just under 205 degrees. Any thoughts are appreciated!

by **Stihler** » Wed Mar 25, 2009 8:16 pm

I did a quick look on the Homebrew Digest (http://www.hbd.org) and came across the following post from Homebrew Digest #4125 Sat 21 December 2002:

From: "Ray Daniels" <raydan at ameritech.net>
Subject: Re: hop utilization, Designing Great Beers

This is about altitude and hop utilization. My information on this subject came from Garetz (Using Hops, 1994). On page 137, he gives a correction factor as follows:

TF = ((Elevation in feet/550)*0.02) + 1

Multiply your wort volume by this factor in IBU or hop weightcalculations to apply the correction.

I just ran a little sample calculation to see what the effect would be for your two locations and it showed a drop in bitterness yield of about 20 percent.

As I have brewed entirely in Chicago with a few hundred grand feet of elevation above sea level, I have never had occasion to use or test this
equation. Others may be able to comment on its suitability in settings such as those Dave describes.

Ray Daniels
Editor, Zymurgy & The New Brewer
Director, Brewers Publications
Association of Brewers

This appears to be in response to a posting from Homebrew Digest #4124 in which somebody asked about the difference in IBUs between brewing in the Phoenix area at ~1000 ft and Northern Arizona at ~7800 ft.

At any rate, this appears to be the sort of correction factor you are looking for. You should be able to simply divide the results you get from ProMash by this factor to estimate the IBUs you are getting at 6000 ft with what boil time you are using.

Cheers,

Scott

by **curlyfat** » Wed Mar 25, 2009 9:12 pm

That's the exact kind of information I was looking for. Thanks a bunch! (You're always a well of knowledge :lol:

)

IBU's accuracy and elevation

IBU's accuracy and elevation

Re: IBU's accuracy and elevation

Re: IBU's accuracy and elevation

Who is online

Like on Facebook

Search The Site

Main Menu

Partners

User Menu

Login Form

Who is online