Off Flavor in IPAs

Well... it was my water. Not surprising but also good to determine that.

I also had an environmental engineer friend in the water/wastewater industry review my town's water profile. The chloride level was pretty high (33 mg/L) according to him, in fact double the content compared to the water leaving his Utility's plant. His theory is that I'm very near to a rechlorination point since I'm actually pretty far from any water treatment plant. Also, since I'm so far away there is a good chance my water supply changes between 3 or 4 treatment plants depending on supply and demand.

I went ahead and bought two water filters - sediment filter and carbon filter.

 

I've been having this problem for a good couple of years now. I've replaced my equipment as well. It's interesting to read the previous poster say the problem was water, but my water has a low chloride content (6mg/L) and is UV disinfected. Unfortunately I can't find a local source for RO water locally (ironically because everyone in Norway considers the water to be very good), so I can't test it.

But I'm interested in hearing if @AlexFields ever figured out what the problem is?

 

Did the problem ever go away? Or did you just stop brewing IPAs?

 

I have had a problem like others that have posted here and have dumped 10 batches of IPAs over the last year. I think I have narrowed mine down to chloramines from using tap water for my Starsan. I used Campden Tablets for my brewing water and distilled for my yeast starters but just never thought chloramines from the left over starsan foam would cause it. After a lot of googling it looks like this could be my problem. I'll know in a few weeks. Brewing another IPA this weekend.

I also had a bad diactyl problem from my house yeast (wlp090). Again it was only in IPAs. It must have mutated or something. I switched to wlp001 and it has fixed that issue.

 

I'm posting because for the last three or so batches of my ipas I was having a very similar problem described by the OP.

In each of my kegged ipas I had a very strange muddled earthy flavor that in the backend tasted very bitter and astringent. The beer tasted ok, the aromas were what I was going for, the front end was great and then it just had this god awful lingering after taste. My friends when I asked didn't notice, or care for that matter, but it bugged the hell out of me.

After reading through every post on this forum and others I finally found an answer, a stupidly simple answer.

I have a two tap kegerator and almost always have an ipa on tap. That means the right side tap is almost always pouring hazy magic The beers on the left are almost always something else, usually pilsners, esbs, stuff that isn't hop particle heavy. I always dry hop my ipas and then keg so theres a lot of free matter still floating around. The answer I found was that the inside of my keg faucet has a build up of old hop residue from previous batches. Basically I was filtering my delicious fresh hoppy beer through a filter of moldy, astringent, rotten old hops.

I took off the faucet, soaked it in PBW and rinsed. The first pour after that, from a half empty keg that was previously gross, was delicious. YAY!

I do clean my faucets at least three or four times a year but now I do after each hazy hoppy ipa and I have not had the problem since.

Hope this helps!

 

IMO faucets should be cleaned after every batch, hoppy or not.

 

I always clean my lines too after every batch. You hear a lot of BAs rag on bars for not cleaning their lines, yet it seems many homebrewers are guilty of it as well.

 

I've also been plagued with this metallic off-flavor in my APAs and IPAs. The one thing I've noticed, at least in my experience, is that the flavor gets picked up or intensifies during the dry hop process.

I ferment in a plastic speidel then, move over to a purged keg with hops, and finally to a serving keg (closed system). Some of the samples I've pulled, from the plastic fermenter, have no metallic flavor, but develop during the dry hopping stage and, as a result, in the finished beer.

At first I thought it was because of my mineral additions (gypsum and calcium carbonate). I was brewing 3 gallon batches, over the winter, and had seen a post about minerals causing off flavors in small batches due to a higher concentration. I lowered the amount of gypsum and cc to reflect the collected wort, rather than the total volume of mash and sparge water. This helped but didn't totally rectify the problem.

I've also noticed that the off-flavor will wane given time and as the beer gets colder (or possibly as Co2 is added since I do those two things at the same time). Only once has it ever completely vanished.

I'm pretty determined to figure this out.

 

I have been struggling with this exact issue as well. A weird, hard to explain off flavor localized to just my dry hopped beers. The flavor is slightly metallic, caramelly, medicinal and a slight hint of smokiness. I wash and sanitize every piece of equipment before and after every use. I also have been living in the same house for 5 years, and I brewed some tasty IPAs before (same recipes), so I know its not my water.

My question to those of you who also have this problem is, are you sanitizing with Starsan? I am wondering if we are getting a wild yeast in our beers (ie: Saccharomyces Diastaticus) that Starsan isn't killing, which is agitated by dry hopping.

Starsan is a chlorine based sanitizer and may not be enough to kill some wild strains of yeast. BTF Iodophor is an iodine based sanitizer and is supposed to / marketed as killing off more (1oz of Iodophor in 5 gal of water).

Also, I don't think this is the case, but if oxidation a contributor to this off flavor, has anyone tried crushing your dry hops into a powder before adding to secondary to minimize splashing?

i will try both of these theories and report back after I brew my next IPA!

Anyone else figure this out yet?

 

Star San is a phosphoric acid based sanitizer. Chlorine will kill yeast and mold, so will Iodophor.

 

Although I haven't read this entire thread, if you're getting the characteristics that you're listing, you have an infection of some type. Possibly Brett sp., (because of the phenolics) but it doesn't have to be.

Have you used var. diastaticus in the past, because Saccharomyces cerevisiae var. diastaticaus is not really something that you're going to get from the ambient air. They are saison strains and the infections that they cause are usually caused by cross-contamination from not cleaning well enough between batches.

 

After reading this thread, it seems like cold-side oxidation is the only issue that wasn't properly addressed, but since the OP doesn't brew any more there seems like little reason to follow up on it.

 

I was thinking infection or chlorophenols.

 

What makes you think cold side oxidation? And do you see that related to dry hopping or water?

 

The OP was just one of many people on this thread experiencing similar issues. I have as well. Would appreciate your input on this oxidation!

 

I have to agree with @EvenMoreJesus on this one. This absolutely sounds like cold side oxygen pick up.

I noticed lots of beers that had this problem in my bottling days, and even the odd one in my kegging days. I finally put it together that the APAs and IPAs that had this over ripe fruit sweetness, metallic off flavor also darkened drastically, and every one had this awful flavor... I looked at my process and decided that the flavor in my kegged beers was prevalent only when I was lazy and didn't properly purge my kegs before filling.

The one thing that every batch with this flavor had in common was dry hops or loads of whirlpool hops in combination with exposure to oxygen post fermentation.

Off flavors from oxidation are often written off as only being that papery, or wet cardboard type flavor that develops over many months in the bottle. While true, what we are dealing with in the world of hoppy beers is quite different - it develops within days. You will notice this unpleasant sweetness, a darkening of color, aroma disappearing (often smelling like the sweet off flavor).

For myself, I have not experienced this off flavor (or darkening / aroma loss) since I started vigilantly avoiding O2 on the cold side. Closed transfers, thoroughly purged kegs. Unfortunately I can't offer much advice to those who bottle and like to drink ridiculously dry hopped IPAs... but I know people do it - so keep trying!

 

Just to add - the mechanism at play here could be related to the oxidation if isohumulones creating various aldehydes. The reason very hoppy beers are more prone to this is simply the more hops you add, the more isohumulones are available to oxidize and create aldehydes. Further - boiling reduces isohumulones and humulones, so an IPA with all boil additions will have less chance of developing this flavor. I believe that is why this is such a problem with heavily dry hopped and whirlpooled beers.

(I am not claiming to be an expert on this by any means, so anyone that could explain the actual chemistry of this please step in)

https://onlinelibrary.wiley.com/doi/pdf/10.1002/j.2050-0416.1979.tb06843.x

 

Thanks for the good info. Briansmaude! I appreciate the input. I figured that this was an oxidation issue of some kind, interesting to know more about it- I will have to do some looking at the isohumulones an the aldehydes to understand further. Unless I get a more closed system or start kegging, I am going to hold of on the heavily dry hopped IPA's.
I had wondered if the Ale yeasts I have been using in combo. with the dry hopping could play a part- I have dry hopped a Saison recipe, but only two oz.s, and both times it has come out with very nice color and clarity.