Off Flavor...very strange one

Greetings,

Hopefully this is the correct place to post this question...

I have had a reoccurring aroma/flavor come through in a few beers that can only be described as rubber (not band-aid) and chemical. The off-flavor shows up sporadically over the last hand full of batches. Not one after another. It can show up, then the next few batches are totally fine, then it can show up again. A friend of mine is a certified Cicerone and her best thought was that it was from a chemical reaction somewhere in the process. The confusing part is that it has appeared in a British rye IPA w/British yeast, a rye saison w/Belgian yeast, a porter w/ amarican ale yeast and toasted coconut and vanilla bean, a "small beer" from a huge parti-gyle barley wine (the barley wine was totally fine) but the small beer was like greasy rubber. I have been brewing for 8 years and haven't ever tasted anything like this. Another friend is head brewer fro Lucette Brewing Co. here in town and he cannot figure it out either. Not even how to accurately describe it. I have judged beer competitions and read through off-flavors literature, but cannot think of anything that may have caused this or experienced anything like it. It literally tastes and smells like rubber, no joke. Not solvent-like, not band-aid, potentially medicinal but I have no reason to suspect any yeast issues or remaining sanitizer/cleaners.

I'm just curious if anyone has experienced anything like this before or has any leads. Any thoughts are welcome, thanks all!

Rubbery? Like sulfur?

Actually just read about this the other day in Brewing Classic styles by John Palmer. He calls it autolysis which is where yeast feed on each other and produce a rubber odor. To avoid it he recommends racking the beer to remove excess yeast as soon after fermentation as possible.
Hope that helps.

have you been noticing a lot of dried krausen on the lid of your fermentation bucket?

i had this happen to a friend. he brewed 15 gallons of a stout, 3 different 6 gallon buckets, one got missed on the fermcap and krausened to the lid where when the krausen dropped its almost as if the dried krausen stuck on the lid went bad and then was dropping back into the beer creating an off flavor...

not sure if this is what you were going for but thats just my attempt at assistance

I fermented all the batches in glass carboys that I made sure were very clean and had no residual cleaner or sani in them and there wasn't an issue that I could see with krausen falling into the beer that I noticed. I don't think it is autolysis because the beers were not on the yeast or in the primary very long at all. And it really doesn't smell like sulfur at all...

It really is just lust like rubber.....seriously.....

Were any of these batches fermented with washed yeast?

Have seen a thread or two on here where the poster was asking about the possibility of the rubber bung/stopper being the cause of a rubbery, type, off flavour. Don't suppose that could be a contributing factor in this case, could it?

Ogri said:

Have seen a thread or two on here where the poster was asking about the possibility of the rubber bung/stopper being the cause of a rubbery, type, off flavour. Don't suppose that could be a contributing factor in this case, could it?

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If you use the black rubber from a hardware store that is NOT food grade, you will almost definitely get off flavors from it. Those things smell like the inside of a Harbor Freight store!

I have a feeling this is not the issue considering the OP has been brewing for 8 years. I'm thinking he has a handle on that sort of thing by now.

I'm thinking it's a strange infection, or old equipment, or some other change in process or equipment that has gone undiscovered.

The reason I ask about washed yeast is because of yeast mutation and/or autolysis from multiple generations. Shot in the dark....

Otto201 said:

Actually just read about this the other day in Brewing Classic styles by John Palmer. He calls it autolysis which is where yeast feed on each other and produce a rubber odor. To avoid it he recommends racking the beer to remove excess yeast as soon after fermentation as possible.
Hope that helps.

Click to expand...

hmmm.. mine sits on yeast about 2 -3 weeks after ferm is complete. 4 weeks or so mine always sit. no rubber here. just yummy beer.

Here's a lame idea... What if one of your ball valves is being overheated while the fire is on. If the flame is on really high? I eyeballed inside of one of my valves and it looks like there is a plastic like sealing area. I wonder if those things can melt if exposed to direct flame? There are probably made of high temp Teflon. Maybe the fire is coming from around the pot and directly contacting something? Even a silicone sealing washer will burn eventually in direct flame.

Well, being as we are all shooting in the dark, here goes...

I used to let my beer fall 8-10" from my kettle to my funnel where it would splash and spin down into my fermenter. I noticed that every so often I would pick up the same bad flavor that would all but ruin the batch. Long story short, the best answer I could come up with was the beer picking up something from the air. I've since reduced the cascade and open air contact time and have not had another issue.

Is it possible ur picking up a contaminant from the air?

Thank you all for the "shots in the dark" it's appreciated!

I use the rubber stoppers form homebrew shops that are appropriate for my carboy neck size. I use alcohol in the airlock unless it's a big beer in which case i'll use a blow-off hose into a 1/2 gallon growler with either acid or iodophor.

I don't usually wash yeast, I know the guys from the local brewery so often I use their yeast (Wyeast 1056). I have pitched onto yeast cakes in the past fairly often and at least one batch that had this rubber flavor was pitched onto a cake from another beer. I later tried the first of these two beers and it did have the rubber flavor, as did the beer I racked onto that cake. BUT, after that experience, I pitched yeast from a vial and from a smack pack and still got the rubber flavor in subsequent beers. It doesn't happen every time. It seemed to go away, then would come back, then go away ect.

I us a siphon sprayer for "average" OG beers. The siphon sprayer hangs inside the carboy as the beer comes out of the chiller. So air-born infections are possible, but I've done this method for ever with good results. Not sure what to think...For big beers, I use an O2 stone with minimal splashing into the carboy.

Keep the ideas coming though...it's appreciated. Below is "pretty much" what is in my kettle (keggle). The orange o-rings are supposedly rated to temps over boiling. I am replacing these two rings in suspect that they may be a cause of the issue. The example below is for a mash tun but it's pretty much the same thing I use in my kettle. I have used these same o-rings for years now without problems. Now might be the problem...

http://www.northernbrewer.com/shop/s-s-cooler-valve-w-barb.html

Do you oxygenate the wort before pitching? I'm wondering if the yeast are being stressed out and producing off flavors. Have you tasted the wort before pitching to see if the flavor is present? If it's present there, then you know it's somewhere in the boil process. Have you changed anything about your process lately, or acquired any new equipment?

What kind of mash temps are you using? I struggled with a similar off flavor for some time (only in paler beers), and changed up a number of variables at once. I got a lot stricter about mash temps (I think I was mashing much too low), got a lot stricter about protecting fermenters from light, and started using much fresher hops. But I think one of my biggest changes was that I'd been pitching onto a full cake, which was bringing way too much trub and dead yeast into the new batch.

My mash temps change depending on the beer. Saison mashes are usually low (150 ish), scotch ale usually higher (156-7) as examples. I do oxygenate with an O2 stone and oxygen cylinder. I have tasted the wort before fermentation, I haven't really noticed the flavor...I don't think. Ill change the equipment and see how it goes. Thank you everyone!

Do you notice the off flavor right out of the primary? Are you kegging or bottling? If kegging, maybe something in your CO2 supply?

Burnt plastic/ burnt electrical- had 2 batches develop this few years ago. They weren't back to back, but like 2 out of 3 or 4. All my research and I figured it was chloramines in my water supply. At times the level is too high and has an adverse reaction and the result is this burnt plastic or electrical fire smell (and taste). Since, I have used Campden tablets to treat my water (1/4 tab per 5 gallons) and have not had the same problem since (3+ years). I can't say 100% this was the problem, all seems good now

+one on the Campden tablets. they are cheap so i just throw about 1/2 a tab per 5 gallons just to be sure. i never had my water tested before. this cycle i use works well with the CampTab's. its cheap insurance for the mind!

Yeah, I am listening to the Basic Brewing Radio episode on water chemistry and they mentioned that the off flavor from using non-boiled non-filtered tap water is chemical, rubber. They mentioned that campden tablets, sodium metabisulfate or pre boiling the water can get rid of this.

Do you ever add straight tap water to the beer? Is it possible that you top off post boil? Perhaps your municipal water supply doesn't have consistent additions of choline/chloramines to the water supply?

Hope you figure this out!

Edit, personally I have extremely hard water so I always use bottle or RO water, so I have never tried anything to get rid of cholamines

Bummer.
You say the flavor comes and goes.... Is this from the same batch? or batch to batch? It could be old beer lines in your keg fridge. I had some lines go bad and dumped some beer because of it It was not a rubber taste, but it was not pleasant and took me forever to find the problem...
Good luck!

I brewed a Scottish ale and took a small portion of the wort and boiled it. The idea was to carmelize the wort but if you overdo it then a rubbery taste can result. If I recall correctly this is equivalent to attempting a malliard reaction but burning the subject matter.

So you may be having an issue with your wort sticking to the pot during the boil. Just a thought based on my experience.

KCBrew said:

Do you ever add straight tap water to the beer? Is it possible that you top off post boil? Perhaps your municipal water supply doesn't have consistent additions of choline/chloramines to the water supply?

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The inconsistent levels of chloramines or chlorine are very likely. I've read that every so often a water department may decide to flush the system with higher than normal amounts of these chemicals. And I remember one time water from the tap reeked of chlorine. I called the water department and they told me they had accidentally let too much into the system.

When I started using campden tables, I noticed my beer tasted cleaner. I don't know that I would have called the off flavor 'rubber', but there was a definite difference.

Try campden tablets or a charcoal filter and let us know how it goes!