Author Topic: unknown plastic smell  (Read 827 times)

Offline gigatropolis

  • Cellarman
  • **
  • Posts: 58
    • View Profile
unknown plastic smell
« on: February 07, 2011, 11:11:06 PM »
I few of my hoppy beers have developed a smell that I perceive as a plastic or kind of synthetic type smell but nobody else seems to notice. I would start to get the smell after maybe 4 weeks in the bottle, so the beer would go from this most gorgeous hop aroma to something that that's just not right. The hops in these beers are mostly Amarillo and Centennial.
  I have also started smelling it in other beer. Last week, at a brewery, I smelled just a little bit of the plastiky smell in a very hoppy beer and this weekend bought a six pack of Prohibition Ale and it has this smell quite strong.
  Now, These beers I brewed show no signs they were contaminated and the smell just doesn't seem to fit anything I read about. The beer was Oxygenated quite badly during racking since I'm just getting used to the secondary carboy.
  Why does nobody else seem to notice this smell?
What do you guys and gals think is happening here?

   Thanks,

Offline tschmidlin

  • I must live here
  • **********
  • Posts: 8195
  • Redmond, WA
    • View Profile
Re: unknown plastic smell
« Reply #1 on: February 08, 2011, 01:52:37 AM »
It's possible that no one else notices it because you are sensitive to that compound.

As for what it is, since you get it in hoppy beers I would guess it's some hop derived compound, and since you mention there was a lot of O2 added during racking maybe it is something oxidized.  I've never heard that described as plastic-like, but who knows.

Just a WAG.
Tom Schmidlin

Offline majorvices

  • Global Moderator
  • I must live here
  • *****
  • Posts: 7616
  • Polka. If its too loud you're too young.
    • View Profile
    • Yellowhammer Brewing Company
Re: unknown plastic smell
« Reply #2 on: February 08, 2011, 04:20:49 AM »
The beer was Oxygenated quite badly during racking since I'm just getting used to the secondary carboy.

I wouldn;t bother using a secondary for most ales. Its just a chance to oxidate or contaminate your beer with little added value to the final product (unless you call oxidation final value  ;).) Most of us have gotten away from using secondaries unless you have a stainless steel kegging system that you can use as a bright tanks and, in the process, purge the head space with o2.

As far as the "plastic smell", does it by any chance remind you of cloves or band aid more than plastic? If so, what are you using as a sanitizer? Are you filtering you tap water?
Keith Y.

Vote Jonathan Fuller for Governing Committee!

Offline oscarvan

  • Senior Brewmaster
  • ******
  • Posts: 1707
    • View Profile
Re: unknown plastic smell
« Reply #3 on: February 08, 2011, 05:21:03 AM »
Quote
Most of us have gotten away from using secondaries unless you have a stainless steel kegging system that you can use as a bright tanks and, in the process, purge the head space with o2.

You mean CO2......?
Wooden Shoe Brew Works (not a commercial operation) Bethlehem, PA
http://www.woodenshoemusic.com/WSBW/WSBW_All_grain_Setup.html
I brew WITH style..... not necessarily TO style.....

Offline gigatropolis

  • Cellarman
  • **
  • Posts: 58
    • View Profile
Re: unknown plastic smell
« Reply #4 on: February 08, 2011, 09:26:28 AM »
Using mostly bottled water and some filtered tap water. The smell is nothing clove like and maybe a little close to a band aid (haven't smelled one of those in a while). I sanitize with Star San.

  I have two beers with this smell. One was batch #3 done long ago and the other #5, which was racked to a secondary and dry hopped. I also did a batch #6 Ale that was poorly racked into the secondary before dry hopping, but this beer has held up excellent with no strange smell (yet). When racking that beer to secondary, the hoses were loose (or something) and it kept sucking in air and making gurgling sounds. The bottling didn't go much better, but anyway, that has been the best beer so far.

  So anyway, it's interesting and I need to probably take a few notes or two and find out more what is happening. Homebrewing has made me notice strange smells while judgmentally smelling beers for the first time.
    What's the money like in beer sniffing?

    Thanks for the help,

  Kregg

Online denny

  • Administrator
  • Retired with too much time on my hands
  • *****
  • Posts: 13338
  • Noti OR [1991.4, 287.6deg] AR
    • View Profile
    • Dennybrew
Re: unknown plastic smell
« Reply #5 on: February 08, 2011, 09:28:15 AM »
Quote
Most of us have gotten away from using secondaries unless you have a stainless steel kegging system that you can use as a bright tanks and, in the process, purge the head space with o2.

You mean CO2......?

I'm sure that's what he meant....
Life begins at 60.....1.060, that is!

www.dennybrew.com

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

Offline richardt

  • Senior Brewmaster
  • ******
  • Posts: 1227
    • View Profile
Re: unknown plastic smell
« Reply #6 on: February 08, 2011, 10:09:01 AM »
I'm guessing chlorophenols by your description.  And the delayed emergence of the flaw suggests a process problem during final transfer.

Replace your hoses, especially if it isn't as clear as the first day you bought it or if it has been longer than a year.
I know some brewers that use a new hose for every transfer.  They're cheap.
Clean all the plastic equipment (unscented dish soap and hot water) and rinse well and dry before storage.
Use two different cleaners/sanitizers to help cut down the unwanted bugs.
For example, iodophor earlier on, then rinse well, then fresh dip in Starsan (use RO water only to ensure the pH < 3) just prior to use of the equipment.  Store the StarSan in a 5 gallon Homer Bucket (should keep a long time and remain clear).

Hope this helps--let us know if this fixes your problem.