St. Louis Brews

[tom sawyer]

During the last Brews meeting we tasted pales ales. One of them had an off odor to it that I thought was slightly sulfurous and others described as "cat box". The brewer had used a lot of a new hop called Citra. I had heard nothing but good about Citra prior to tasting this beer. It is supposed to be citrusy (obviously, its "Citra" after all) leaning to the tangerine/orange. I had heard of other hops being "catty" though, specifically Simcoe and Summit. Summit also can give off a slightly oniony flavor but this supposedly goes away. Onion is a sulfurous compound. I also know that sauvignon blanc has a citrusy grapefruit flavor and that this wine has an element of "cat pee" that is perfectly acceptable.

In any case, this got me thinking about possible links between citrus flavor/aroma compounds and the catty aroma. I'm a biochemist by training, I can't help but think this way. I did a little research online and found some flavor/aroma analysis of citrus and found that a couple of the prominent grapefruit flavor compounds are mercaptan-linked ketones. Hence an association with sulfurous aroma, which grapefruit is described as having. One of the compounds was also described as having a catty aroma. Viola! We have a direct link between citrus aroma and these other aromas.

I don't know whether the exact compounds exist but I do think its reasonable to assume the same sorts of chemicals are involved.

[zimman]

Very nice analysis. Well the beer your were speaking about was the APA that I brought. What was strange about it was I bottled 1/3 of the batch and kegged the rest. The bottle conditioned beer had a very nice tangerine/citric aroma and taste. Its was a very pleasant beer in my opinion. Dale also had a bottle and enjoyed the beers aroma and taste. However the beer I brought to the meeting was out of one of the 2 kegs I used. Sanitation was not an issue. The beers profile was quite different from bottle to keg.

So naturally Dale and I were shocked when we tried the kegged version vs. the bottled version.

What do you think would cause the alteration of its aroma and taste?
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Primary:
Secondary:
Bottled: Nut Brown
Kegged/On Tap: Sweet Stout, Irish Red, Scottish 80, DogFish 90min, APA, Bud Select

[Dale P]

The bottled part was very nice, in your face tangerine flavor. I liked it very much. I'm also confused by this difference in the beers.
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On Tap
Cider
Grozet
American Brown Ale

http://penrosepicobrewery.blogspot.com/

[tom sawyer]

When I tasted the beer I initially detected more of a mercaptan type of aroma. Others at the table mentioned the catty characteristic. Since they are kind of related I am assuming it was just a matter of who is more sensitive to what aroma compound. The flavor was good. I think you might be able to release some pressure on the keg and outgas some of the aroma compound, then charge with CO2 again. I did this not long ago with a dunkelweizen that had some sulfur and was rushed to the keg anyway. It turned out with barely any sulfur, at a small sacrific to some banana aroma.

Very strange that keg vs bottle would be different. That suggests to me that there was more going on than just the hops. Do you purge your kegs when you start carbonating? Did you bottle the same day you kegged? Just wondering if there was some bit of oxidation, or if additional fermentation changed something.

Did you taste the brew when you bottled?

[tom sawyer]

I was just reading Stan Heironymous' new book on wheat beers, and found something realting to Citra and cattiness. Steven Pauwels of Boulevard Brewing makes a wheat beer with Citra hops because "they have characteristics of a Sauvignon blanc." He even bottle condtioins his wheat wine with grape juice.

[zimman]

[tom sawyer]

Well in that case there is no difference and they taste the same.

[Michael]

Hey Guys

Question on the terminology. Wasn't the term "catty" used to describe "skunky" in Europe because there were no skunks and therefore no ability to understand that profile? So when you say "catty" are you referring to "skunky" or some other aroma character?

Mike
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My Indian name is "Running With Beer"

[Lynux]

"catty" refers to the smell of cat pee.
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A good brew will quench the parched soul

Primary - ?
Conditioning - ?
Tap 1 - IPA w/ Citra
Tap 2 - Porter
Tap 3 - Dusseldorf Altbier
Bottle - Cider, Apollo 13 Rye PA, '10 Barleywine

[tom sawyer]

I think there's an element of sulfur to it as well, in fact thats what I detected. In the form of a mercaptan stuck to another organic compound it takes on new olfactory dimensions.

[blksabbath]

Interesting...I just had a few beers at Barley Island in Indianapolis that use a Citra/Summit/Centennial combo. I thought they tasted like a mouthfull of fresh lawn clippings and garden scraps. Or like a wheatgrass shot aftertaste.

When I think of catty, I think of a tomato plant...not the fruit, but the plant itself with a touch of sulfur. That also seems to fit that hop combo.
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Almost anything is possible with beer and duck tape.

[tom sawyer]

You make it sound so tasty!

I have a pound of Centennial and Summit, and I was considering throwing some Citra in as well. Just not sure I want that much cattiness. Then again, I've been using Simcoe and Amarillo and loving it so what the heck.

Seems like this particular aroma can be more or less prevalent. I wonder if its volatile enough that using a late addition in the kettle will get substantially outgassed during fermentation? Seems like dry-hopping would leave all the catty/grassy/stinky goodness intact.