Need help identifying off-flavor

Discussion in 'General Brewing Discussions' started by Edan Z, Jul 23, 2017.

  1. Edan Z

    Edan Z Member

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    After the first two batches of home brew, I'm in need of some help identifying an off flavor that is persistent in my first two brews, made with two different yeast strains, different malt, etc.

    Reading about the common off-flavors hasn't helped. I can't tell if it's band-aid, catty, DMS, etc.

    Having worked in a genetics lab, as a molecular biologist, I am definitely obsessed with sanitation. I doubt there is some bacterial infection in both batches causing the problem. I am anal about sanitation, using a detergent to clean all the equipment, AND using Star San as a final rinse. However, unbeknownst to me, the powder detergent I bought with my kit was chlorine based. I bought it thinking it was an oxi-clean type powder, but I have suspected it was bleach from the smell (the ingredients are not listed on the package).

    I have two possible theories about the of-flavor:

    1. The chlorine cleanser, which I rinse with (chlorinated) tap water perhaps permeated the plastic fermentation buckets sufficiently to react with the fermenting beer to cause chloro-phenols to show up. I use bottled water for the mash, so the source of the chlorine would be the sanitizer and the tap rinsing water.

    2. Both of my first batches fermented in a building cellar that does smell very musty. My initial thought going down there to set down the fermenter was that this could become a problem, especially if the bucket is sufficiently porous to allow the musty, mildew smell in the air to make it into the fermenter.

    Now, for both of my first two batches, the smell/taste of the fermenting wort at about two weeks into fermentation was great. I only began to detect an "off-flavor" in it after the 14 day mark in primary. It was mild at first, and intensified about 5 fold after bottle conditioning. It definitely became more pronounced after a week in the bottle.

    I have a hard time identifying it. I can't tell, it it's baid-aid, catty, wine cork, or what. I'd hate to keep doing the same thing expect a different result. If there is someone (preferably in Europe) with experience identifying these things, I'd love to send you a bottle of this latest batch so I can get some help identifying and solving the issue.
     
  2. sn00ky

    sn00ky Active Member

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    What type of brews?
    14 days I would think anything permeating is unlikely, and in primary, c02 would be trying escape, but that said , is it possible it oxidized? I find hard to believe it would that quick however, especially in a primary.
    Are you doing lager styles ? Does butterscotch come to mind? Could be diacetyl?
     
  3. Edan Z

    Edan Z Member

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    I have racked my brains trying to figure out if it's diacetyl, DME, etc. None of the online explanations of off-flavors seem to fit.

    I have used Belgian yeast for both batches. Safale be-256 and wlp 530. Both have been attempts at Belgian blondes.

    The first batch fermented at 60°F the second was hotter, around 72°F. It can't be oxidation, after all, 14 days into fermentation, there's a ton of co2 being given off.

    I do a variation of BIAB, and I squeeze the bag.

    I can't for the life of me describe the off-flavor, but it's off putting. Perhaps reminiscent of wine gone bad. There's a wine quality to it, but it's not as simple as vinegar. I could easily recognize that. Sherry like? Maybe, but again, I tasted the off flavor in the fermenter before siphoning and bottling around day 18 in primary, and I never opened the lid during that time. I'm sure it's something common, I just lack the experience to identify it.

    I just don't know what diacetyl or DME taste like. However, both batches sat at room temperature for a week, around 75°F after final gravity was reached, and I sensed that the off flavor was produced during that time. How could it be oxidized already? I had been taking samples prior to that, and they tasted great. A week later into primary, it was there.

    I'm stumped.
     
  4. CRUNK

    CRUNK Well-Known Member

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    I would need more in depth details, from your yeast starter, to clean up, but we will figure it out, don't panic, these folks can definately help solve this.
     
  5. Ozarks Mountain Brew

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    what did you use to lower your ph?
     
  6. CRUNK

    CRUNK Well-Known Member

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    Are you positive about your grain bill?
     
  7. Ozarks Mountain Brew

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    a musty smell comes from hops and usually from the hops starting to mildew, this can happen if you open the fermenter then expose the krausen to air and hops are in the krausen then leave it for a long period of time. my practice is "never open the fermenter" for any reason
     
  8. sn00ky

    sn00ky Active Member

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    If FG is reached, you may have missed the window for diacetyl rest, I think aiming so that 80% of the likely attenuation has taken place, then up the temps. Not saying it's the cause, but I wouldn't rule out based on what you've mentioned...
     
  9. Edan Z

    Edan Z Member

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    #9 Edan Z, Jul 23, 2017
    Last edited: Jul 23, 2017
    Not a thing. I haven't delved ino PH yet. Didn't think it could be so critical as to make beer taste repulsive.

    Yes. Both times, I pretty much upped the temps after two weeks in primary, meaning FG had been reached for some time.

    Now, reading brew like a monk, I noticed that Trappist brewers only do primary for 5-7 days maximum, before lagering for three to four weeks, essentially, sending the yeast into dormancy. Could it be that Trappist strains go funky if left in primary too long (3+ weeks)?
     
  10. J A

    J A Well-Known Member

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    That just sounds wrong... :rolleyes: :D:D:D
     
  11. Trialben

    Trialben Well-Known Member

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    My 2c would be your water source:rolleyes:? No chlorine getting in there and stressing out them yeast it can cause some phenolic problems I've herd...
     
  12. Trialben

    Trialben Well-Known Member

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    Oh and what do you ferment in. And if and when you cold crash sometimes your airlock cam suck in its contence causing problems not from personal experience I go from 18c to 1c most crashes and haven't had a big prob. My taste buds are biased though lol.
     
  13. CRUNK

    CRUNK Well-Known Member

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    After doing some research based upon what I have read I believe that you may have had some residual chlorine in your system if it were me I would get distilled water fill up your pot boil it and run it through your system for 10 or 15 minutes to try and get that cleared out real good let the water cool put some sanitizer in run that through your system and drain it
     
  14. Nosybear

    Nosybear Well-Known Member

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    Fourteen days sounds like diacetyl. It's not present in the "green" beer - its precursor is. Then, with age, it oxidizes. If you get "good" diacetyl, it's buttered popcorn or butterscotch. If you don't, you get rancid butter. One way to tell is to take a sip and see if it feels slick when you rub your tongue against your palate - that's a pretty good sign of diacetyl. Chlorophenols from chlorine in the sanitizer should have showed up immediately.

    And you may have more than one off-flavor going on at once. That makes it tough - the palate training we receive is in identifying ONE off flavor at a time. When they show up as they usually do in nature, combined with each other, makes things difficult.
     
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  15. Edan Z

    Edan Z Member

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    Both batches have fermented in brand new buckets with S style airlocks. I haven't cold crashed yet.

    True. It could be a combination of things, including diacetyl. If cold lagering makes the off flavor less perceptible, what would that mean?
     
  16. Nosybear

    Nosybear Well-Known Member

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    If you're saying that cold lagering makes the beer taste better even once it's warmed, it could be one of two things. First, tannins. Think heavily oaked red wine, the astringent feeling kind of like sucking on a tea bag. Second, yeast. The yeast itself has a flavor that some (including me) don't find pleasant. Cold drops both of those out of suspension in beer and improves the beer's flavor over time. But diagnosing an off-flavor remotely, unable to taste the beer, is quite difficult!
     
  17. Edan Z

    Edan Z Member

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    #17 Edan Z, Jul 24, 2017
    Last edited: Jul 25, 2017
    Well, I'd be more than happy to ship some out! If there are any takers.
     
  18. sn00ky

    sn00ky Active Member

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    I am no where near the pallet of the other people involved here , and I am in Canada, but always willing to try a brew! I would consider returning the tasting to make up for it! No idea what it would cost to ship over border ?
     
  19. Trialben

    Trialben Well-Known Member

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    Well would be exy to ship to Aus for taste test lol.

    Only other thought would be enter it into a local comp for feedback...
     
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  20. Mark D Pirate

    Mark D Pirate Well-Known Member

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    Great idea Ben , even your local brew club may have some bjcp certified judges they can give you feedback , be prepared to get your feelings hurt though
     

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