Author Topic: measuring home grown hop acid content  (Read 4548 times)

Offline Kirk

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measuring home grown hop acid content
« on: October 17, 2010, 01:07:59 PM »
anybody know a good way to measure the alpha acid content of home grown hops?  I was thinking it would be making a tea with something like 1 oz hops in 1 qt of water, boiled for 30 minutes, take a ph reading, and voila!  Is it something like that?
Kirk Howell

Offline tschmidlin

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Re: measuring home grown hop acid content
« Reply #1 on: October 17, 2010, 01:43:49 PM »
No.  The ASBC method for measuring alpha acids in hops involves several reagents and a spectrophotometer.

To do it at home your best bet is to make the tea like you mentioned, but compare it to a tea made from hops of known bitterness.  With careful measurements you can probably come pretty close to the actual alpha acid, but I haven't tried it.
Tom Schmidlin

Offline bluesman

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Re: measuring home grown hop acid content
« Reply #2 on: October 17, 2010, 05:29:39 PM »
No.  The ASBC method for measuring alpha acids in hops involves several reagents and a spectrophotometer.

To do it at home your best bet is to make the tea like you mentioned, but compare it to a tea made from hops of known bitterness.  With careful measurements you can probably come pretty close to the actual alpha acid, but I haven't tried it.

+1

As a homebrewer it's really not worth the investment to have the capability.

I think the best way to measure the hop acids in said hops is to brew a batch of beer and drink it.  ;D
Ron Price

Offline Kirk

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Re: measuring home grown hop acid content
« Reply #3 on: October 18, 2010, 06:37:52 PM »
Thanks you guys, you're the greatest.  Yesterday, I made a tea out of my home grown Fuggles, tasting it at 5 minutes, 20 minutes, and 40 minutes of low boil time.  It tasted bitter of course, and slightly earthy.  Not too grassy at all.  Then I did the same thing with Northern Brewer pellets I had in the freezer.  Quite grassy, and I don't think I'll be using them from now on.  It really helped me to "taste sample" the hops in a tea.  I had been using Norhern Brewer a lot for bittering.  But, when I sat back and analyzed the taste of what the hops were doing to my finished beer, I thought "too grassy", and that I had to make a change.  In my last batch, I used Cluster for bittering.  I liked the result much better.  Had I saved some, I would have yesterday also made a Cluster tea.  Next time I will.  Hops are spices, are they not?  It really helps to taste them, in solution, unsweetened, as opposed to relying on someone else's characterization.
Kirk Howell

Offline denny

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Re: measuring home grown hop acid content
« Reply #4 on: October 19, 2010, 08:47:11 AM »
as opposed to relying on someone else's characterization.

This is a point I try to make to every brewer who asks for advice on ingredients.   Of course, it's always valuable to ask other people's opinions, but ultimately you'll have to decide for yourself.
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Offline Kirk

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Re: measuring home grown hop acid content
« Reply #5 on: October 22, 2010, 10:15:53 AM »
Thanks Denny.  I may start a new topic on this.
Kirk Howell

Offline chinaski

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Re: measuring home grown hop acid content
« Reply #6 on: October 22, 2010, 10:40:21 AM »
My homebrew club, The Green Mountain Mashers, and I did an experimental test of the hop tea methods detailed here:
http://home.netcom.com/~dluzanp/backyard.htm

We tested the methods for three varieties and had 5 or 6 folks independently estimate the %AA of homegrown hops.  We significantly underestimated the true (laboratory measured) %AA in 2 of the 3 varieties.

  I'd like to post the results as a graph but can't figure out how the "insert image" button works.

I'd like to pursue this further sometime in the future as I grow a lot of my own hops.  My latest brews were formulated for the low end of typical commercial hops and adjusted by taste during my brew sessions.


Offline denny

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Re: measuring home grown hop acid content
« Reply #7 on: October 22, 2010, 11:08:03 AM »
  I'd like to post the results as a graph but can't figure out how the "insert image" button works.

You can't insert an image directly.  You need to have it hosted somewhere and then you can insert a link.
Life begins at 60.....1.060, that is!

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The best, sharpest, funniest, weirdest and most knowledgable minds in home brewing contribute on the AHA forum. - Alewyfe