Hop Chemistry

Just listened to this hop chemistry podcast from beersmith,

http://beersmith.com/blog/2012/05/13/hop-chemistry-and-beer-with-james-altwies-beersmith-podcast-38/

it's pretty good. James Altwies from Gorst Valley Hops talks about adding some hops well after flameout.
He said if you cool your wort down to 120F and then do a hop addition you'll get some really intense hop aroma.

He talks alot about hop oils and their flavors,
these are his descriptions from the podcast

Myrcene-most of the hop oil, usually 40-60% of the total oil, mellow herbal, boils at 280F or 250F(other sources say 333F)

Humulene-nugget hops, herbal, unique hoppy smell, boils at 150F

Caryophyllene-centennial, citrusy, boils at 110F

Farnesene-saaz,sterling, musty, spicy, boils at 79F

He said you get the grassy flavors mostly from fresh undried hops, Hexanol was the specific compound for grassy.

He also talks about glycoproteins in the wort acting as a soap to capture these hop oils.

If you're interested in hop chemisty give this podcast a listen too,
and the previous podcast on beersmith with Stan Hieronymous is also pretty good,
Stan talks about hops too, and a new book he's coming out with on hops.


This is unrelated to the podcast, but since I'm a fan of Sterling's flavor
which James said is from Farnesene I looked this up on Wikipedia.
Farnesene is emitted by aphids upon death to warn away other aphids, several plants synthesize it as a natural
insect repellent. Also it is the chief compound in the scent of a gardenia flower,
making up 65% of the headspace constituents.

Great info...thanks for that. I'm growing some Sterling this year, so looking forward to using it.

Really interesting stuff, and I haven't even listened to the podcast yet. Thanks for the heads up.

Very cool!!

Here's a couple other links with some good info on hops

http://beersensoryscience.wordpress.com/2011/08/08/myrcene/

http://morebeer.com/brewingtechniques/library/backissues/issue2.1/tinseth.html

http://inhoppursuit.blogspot.com/2011/07/hop-oil-is-bigger-better-preview-of.html

this last one is a link to a speech from Vinnie Cilurzo from Russian River
Vinne starts at about 1:45:30 in.

http://thebrewingnetwork.com/shows/The-Sunday-Session/The-Sunday-Session-06-26-05-First-Russian-River-Appearance

I've actually just started doing some more in depth hop analysis and just scratched the surface of a few google links. Thanks for the links.

No prob. I've been pretty interested in hop oils for a few months now, and have been trying to figure out what the flavors are I've been tasting, and how I could maximize them. I found this blog, here's a link
http://beersensoryscience.wordpress.com/2012/02/16/linalool-fresh-and-floral-hop-aroma/
When I read that blog article on linalool I knew it was one of the flavors I was getting. The article describes linalool as, "very pleasant sweet, tropical, fresh floral character, but is also not unlike the aroma of Froot Loops® cereal." The best info I've found on hops so far, particularly hop oil, has been in the full version of Brewing Science and Practice textbook pdf I found online, not the google version that's missing pages.
This pic here is from a slide presentation from the craft brewers conference

It breaks down the hop oil into 3 main groups you can see in the pic.

Besides the linalool, which I think I taste in Crystal hops, I think I've also tasted geraniol or possibly nerol in another beer with heavy late whirlpool additions of Amarillo and Centennial. Geraniol from what I've read smells like rose, and nerol is a more fresh rose flower smell. I'm not sure if I'm getting the rose smell from the Amarillo or the Centennial, but I'm definetly tasting it. I've grown a small rose garden with about 8 different varieties for the last few years, so I feel pretty confident saying it's a rose smell I'm getting. I guess when people say floral, maybe they are really referring to geraniol or nerol, who knows I'm just speculating here.

I've been brewing only single hop beers lately with heavy late additions, and even additions after chilling has started, to really get all the hop oil to stay in the wort and not boil off, and the hop aromas have been very good.

One other thing I learned recently was that Matt Brynildson of Firestone Walker Brewing was a hop chemist before he worked as a pro brewer. He did an appearance on the Brewing Network where he gives alot of very detailed hop chemistry info, here's a link to that
http://thebrewingnetwork.com/shows/The-Sunday-Session/The-Sunday-Session-08-21-05-The-Drunk-Show
this is not one of the best episodes of The Sunday Session, but if you stick with it Matt really gives some good info there.

Here's a link to the most up to date article on hop chemistry I've found, this is a must read if you're into hops

http://www.mnammyslenky.com/hopchemistrypaper.pdf


Here's just an interesting table and spider graph I found in an Oregon State University article

I am about the start the article, but since this thread has revived I figured I would post something I found quite interesting.
http://www.countrymaltgroup.com/downloads/zythos.pdf
I can't get the pdf to work, but anyways, check out the stat on the tables:Citrus-piney fraction and floral estery production. This is perhaps the most interesting measurement I've seen in hops. As the base oil's chemistries are too complex to readily calculate. With that comparison you can really get a vibe for the intensity and balance of each individual hop type.

I also bought the new IPA book that just came out. If I extract any useful info I'll post it.