Off Flavor - Oxidation?

[tagz]

arghh! i cant figure this thing out! brewed a red ale this time. used fresh 2012 hops (ahtnanum and citra 2 oz spread across 10 min and FO). tasted fantastic out of the primary. big bright tropical flavor. hop aroma faded substantially by after carbing in the keg. so i threw in 2 ounces of dry hops for 4 days. it was super cloudy when i pulled out the dry hops, but big mango aroma with some musty orange from the ahtanum. then three days later its an herbal mess. tastes like every other hoppy beer i've made. just green, vegetal blech on the tongue. i've now officially tried everything. i don't get it.

i just scored 2nd and 3rd place metals for my wit and brown ale, so my process must be pretty solid. but, this hop thing is killing me.

 

[beersk]

I've had similar issues. Do the flavors get worse over time? My issues are diacetyl developing in the keg and eventually turning butterscotchy, I think, from dirty kegs/having never run a dip tube brush through the dip tubes and getting infection. The pales and IPAs start out tasting amazing the first week, then they change...
There wasn't gunk in the dip tubes, but there could be build up that BLC or PBW isn't getting off when I clean the kegs. I'm currently running an experiment where I'm going to bottle half and keg half a batch, see if they remain stable.
I feel your pain. It sucks to have an awesome beer, the best IPA you've had in a long time suddenly turn to sh*t.
Perhaps it isn't your issue, but things to think about.

 

[tagz]

Interesting. Let me know about your bottling experiment.

 

[tagz]

Ugh. My current beer, jamil's amber red ale with 2 oz dryhop (4 days), is getting worse and worse. Any aroma that was there at the beginning faded after a few days. The flavor has turned more and more vegetal and bitter. I'm really out of guesses at this point. I lean toward water chem, but I'm using brun water for acidification and calcium chloride and gypsum additions, and none of my numbers as way out of range. Man, the dryhop sack smelled so great...

 

[OneShot1]

Ugh. My current beer, jamil's amber red ale with 2 oz dryhop (4 days), is getting worse and worse. Any aroma that was there at the beginning faded after a few days. The flavor has turned more and more vegetal and bitter. I'm really out of guesses at this point. I lean toward water chem, but I'm using brun water for acidification and calcium chloride and gypsum additions, and none of my numbers as way out of range. Man, the dryhop sack smelled so great...

When did you dry hop? I have dry hopped when the airlock was barely bubbling and it still blew out all the aroma. I ended up disappointed. I am speculating but try adding the dry hop when the fermentation is completely done.

 

[tagz]

Good thought. It was completely done and kegged. I dry hopped after pulling a glass or two, because the flavor was so minimal. I dry hopped in the keg. Warmed to 68. Only had to open it to pull the bag.

 

[cwheel]

I'm in the same boat. Been battling this with my IPAs for a while now. We should trade bottles to compare. The taste is hard to describe, but often it tastes slightly "chemical" - grassy maybe. I have often attributed it to the fact that I have a difficult time getting a nice big malt profile on my IPAs, and this relative thinness in flavor allows the chemical taste to come through even more. I'm fairly positive it is not simply hop flavor that I am tasting.

At some point (when I get my act together), I am going to keg half a batch and bottle the other half. I can't believe this would be the issue, but I'm wondering if the CO2 I get from my local "welding supply" shop is contributing something to it. I don't know...

I have two 7.3 gallon conical fermenters that I use to minimize infection and oxidation, and although they have definitely improved my beers, they still don't completely get rid of the chemical taste in my pale beers.

And I use PBW to clean and starsan to sanitize my fermenters, kegs, etc...

By the way, are you on a well by any chance?

 

[Rake_Rocko]

Here's just a thought, and you don't have to try it but I would consider brewing a "control" brew. Go to the store and get bottled drinking water and brew with that without adding any salts or other things to adjust your mash ph.

Only reason I say this is because I do this with all my beers and my IPA is by far the best one I brew. I dry hop as well. That way if you produce a great beer with the store bought bottled water, your culprit may have something to do with the water you have been using.

Just a thought.

 

[tagz]

That's the route I've been thinking. I made 2 decent pale ales when I first started brewing, and I'm pretty sure I was using Poland spring water at the time. I'll give that a go. And if that doesn't work I'm going to throw all my citra, galaxy, and simcoe into a bonfire to burn the evil spirits trapped inside them.

 

[Rake_Rocko]

Or you can send them to me!! Haha!

 

[Jwood]

wow, I have the SAME exact problem with my hoppy beers. They just taste a bit dull, slightly vegetal, a little fusel-alcoholy, and caramel-ish (even though I use barely any caramel malt). I mean, the beers are good, but they are held back from being great.

Have you figured out what the problem was yet? I'm considering replacing all of the posts on my kegs just as a precautionary measure. I feel the actual keg is the last thing left...maybe there is some sort of infection going on. I've tried the water adjustments, tried purging EVERY step with CO2, dry hopping for less than a week, pitch enough yeast, aerate, ferment at the correct temp, etc. etc.

 

[tagz]

Unfortunately no. I haven't cracked this one yet. I'm running out of variables it seems. At this point I know my process is solid because my other beers come out on target. I actually did really well in a competition with my brown and wit. I suspect that it must be something to do with the water, even though I now use a filter, potassium meta, and make water adjustments. Ive also talked to other local brewers who have no problem with the water. even given that, I'm considering grabbing some store bought water for a test batch to see if it makes a difference. Im also tempted to bottle up a batch to see if that plays in. Here are the angles I have looked into...

Hop Freshness & Type
Oxidation
Mash pH
Sulfate levels
Dry Hop Duration & Elimination
Leaf vs Pellet

 

[Wesjmc]

Hey Tagz, any new developments?

After brewing a couple delicious not-too-hoppy beers I recently brewed Janet's Brown Ale thinking a hoppy (also dry hopped) brown ale might stand up better to oxidation than a hoppy pale ale due to the darker malts. I only opened my primary fermenter once prior to kegging to take a hydrometer sample and toss in the dry hops. After 5 days I cold crashed it to drop the hops and help settle the yeast, then I racked to a keg. The keg had been filled to the top with star san then drained under pressurized with CO2. This should have filled the keg 100% with CO2 before I racked the beer into it. I then purged it 5 times and force carbed it. 2 weeks later it tasted young, but full of hop flavor/aroma. At a month it tasted totally muddled and the hop flavor/aroma were gone. The bitterness has a twangy lingering quality that is anything but crisp. What gives???

Could the issue come from transferring kettle hops and trub into the fermenter? I use whirlflock and pour through a strainer, but still get some sludge in the bottom of the fermenter.

If you've had any success or insight I'd love to hear how your endeavor is going.

 

[tagz]

So, I brewed a pale ale with fresh pellet hops (2012 Citra & Ahtanum) to see if hop age made the difference. It did not. Amazing aroma from the Cirta dry hops as I pulled them from the keg. However, after 2-3 days things got veggie/earthy. It was tolerable for a while, but I dumped the last gallon or so.

Last month, I decided to start brewing a series of light profile session ales with 1968 and a feature ingredient or two. The first one featured biscuit, which was decent, but I couldn't bring myself to add any flavor hops. It ended up tasting like Sam Adams. Made me want to give the hops another go...

I brewed a similar beer, dropped the biscuit and added a touch of aromatic. I was only feeling mildly brave so I used just an ounce of Mosaic. 20 IBUs from Warrior at 60, half an ounce whirlpool at 140 degrees, and half an ounce dryhop (3 gallon batch). Nice melon, apricot, tropical fruit for the first week. Things got slightly earthy for a few days. Then it settled into a more general fruity hop flavor. I thought it was going south that second week but turned out great in the end.

So I'm not positive about what is going on here but I would recommend trying a new hop, brew a single hop beer, and use a light hand. I think that using certain hops in large quantities at the end of the boil may be a factor. I'm brewing a very similar recipe to the Mosaic tomorrow, this time with an ounce of citra. I'll report back.

 

[Wesjmc]

Well I'm glad you're having a small bit of success, but it sucks that you're avoiding brewing hoppy beers because of this issue. I stayed away from brewing hoppy beers for a bit as it's all I could do to stay sane. After getting my process down with tons of other great beers it's incredibly discouraging to have to force down or even dump every hoppy beer I make. Keep me posted and I'll do the same.

By the way I love that yeast (I use WLP002). It ferments fast without an absurd amount of blow off and it drops clear. It's pretty neutral, but gives a bit of character. I love it in porters.

 

[jakenbacon]

I know these issues are getting worse over time for you all but I noticed a huge leap in my IPA's when I started adding gypsum to my filtered water. I can't say I experienced what you all are but the hops certainly didn't pop like they should have, and I would say it wasn't 'right'. Maybe the off flavor is unnoticeable with that fresh hop aroma, and when it fades, you taste the funk. Just a thought....

 

[NHMikeT]

tagz,
Any samples from this latest batch? I've been following your thread as I have the exact same issue, and have also attacked each of the possible issues similarly, although in a different order. I'm onto potential oxidation now, but wouldn't think it'd take hold so quickly.

My latest batch is a Mosaic/Cascade APA/IPA that tasted fantastic at transfer time and at 1 week in the keg (albeit slightly young) and has now fallen into the "dull" state... For this batch I used all vacuum sealed hops from HopUnion.

Anyway, I'd be very interested in your latest experience.

 

[tagz]

Well, I brewed the Mosaic recipe again, but swapped Citra for the Mosaic. Ive been drinking it for about a week now and it seems i have another clean tasting pale ale. It had a nice tropical nose when I pulled the first few pints and now its turning into a more general hoppiness. But, its definitely a clean flavor; no earthy, vegetal, herbal flavors. So that makes two batches without the issue. The two variables I've been working with in these batches is hop strain and quantity.

After working through a series of commercial examples, I've come to the conclusion that Amarillo has the earthy notes that I find objectionable. So that accounts for two of the batches. That said, I did have a ahtanum/citra batch that developed the same flavors. I tend to blame that on the ahtanum, because I know it has that musty aroma based on my experience with stone pale ale. I did use the ahtanum in a saison in very small amounts and I believe got a nice grapefruit edge from it, with no earthy favors. so i think the fact that i was very reserved in the quantity helped. I doubled the ahtanum addition on my latest version so we'll see how that plays out.

All this makes me think that some varieties give off these flavors when used in large quantities. I also think some of us are more sensitive to the flavors. In the book For the Love of Hops, it says that we all have over 1000 aroma receptors and we only use 300 or so of them. It also explained that not everyone uses the same 300, so we may be able to detect aromas that the next guy will not.

My bottom line at this point is to keep trying different varieties and slowly increase the quantity I am using. Im not at the point where Im getting the juicy hop flavors I'm looking for but at least i haven't had to pour any batches out lately. I'll probably use some centennial next round, as I know I've never had any unpleasant flavors with Two Hearted or home-brews that have highlighted the hop.

 

[NHMikeT]

Hey - thanks for the update. I'm leeting that keg sit another week before touching it to see if its character changes again by 3 weeks in. Since you should mentioned the Centennial - I've got NB's Dead Ringer dry-hopping now and plan to brew BierMuncher's Centennial Blonde next, as I've got quite a bit of these in the freezer.

I don't have For the Love of Hops, but sounds like a good read. I can attest that my girfriend always describes the flavors and aromas differently than I do.

 

[grathan]

Tagz, still having luck having swapped out hop varieties?

I seem to be having troubles with oxidation type flavors from dry hop.

NHMikeT, Wesjmc, Jwood, Cwheel- you guys have any luck figuring out your off flavors? Anyone wanna compare brewing techniques?

I was thinking about carb pressure and its affect on oxidation. I've made some hoppy beers without the flavor so i am thinking it's process related.

 

[NHMikeT]

grathan,

In response, I've since brewed two beers with zero off-flavors, but they were not hoppy brews. The one that's drinking now is an excellent amber, about 35-40 ibus from one bittering charge of Chinook (finishing hops were with wild/backyard hops).

The only thing I changed on these brews was the water. I used well water from my girlfriend's parents' house instead of treating my tap water (I had both tested by Ward Labs). I'm thinking (hoping...) that for some reason my sink Pur filter and campden treatment did not remove all the chloramines in the tap water.

I brewed an IIPA today using RO water from the machine at the grocery store, so I'll know in 6-7 weeks if there's an issue. Interesting you mention carb pressure... I've only been kegging for a few months now, and I only feel like the carbonation influences the flavor in the first few days (I usually wait 10 days before starting to really drink a keg).

Feel free to PM if you want to discuss process in more detail.

-MT

 

[grathan]

If you don't mind, I'd discuss process in the thread? I came here from a Google search about dry hop oxidation and there isn't really much info out there. So perhaps this could help someone else.

My ipas taste great at first keg pull. The very next day things start going bad. And they continually get worse. Beautiful tropical fruit flavors/aromas gone. Replaced by dull, sherry, cardboard. I would rather not drink after day 3 and 3 months things still are get progressively worse to the point it no longer resembles beer.

This has me believing that carbonating plays a hand in things. I know that I may be over-carbing and I am new to kegging also (I don't have a set process yet, sometimes I crank up to 30+ psi and sometimes I let sit at serving pressure for 2 weeks). My latest ipa was cranked to 37psi and the flavors disappeared almost overnight. Could be carbonic bite masking the flavor, it's not ruled out yet, but hard to believea beer goes from best ipa ever tasted to bleh in the coarse of a single day at 15 psi 35*F. My wild theory is that high pressure (30+psi) or the presence of cabonic acid rapidly progress oxidation.

Another theory not discussed much at all in the brewing community. Oxidation of hop oils by aerating wort with pure oxygen. I use an 02 tank. 0.2 micron stone with pressure so that not maximum bubbles, but some reach the top of the wort for 0-2 minutes.


Another thought is oxidized hops causing oxidized beer. I was trying to use up an old 1LB bag of centennial in all my oxidized ipas this year. Again, there is nothing turning up on Google for this happening so just some wild theory.


My most solid lead at this time is my fermenter. It is a massive 8 gallon plastic speidel tank that I dry hop and cold crash in. I've made hoppy beers in glass carboys this year that didn't oxidize. I've brewed hoppy beers in bottles that taste fine after 5 years. I suspect the massive head space ( at least 3 gallons ) after opening to drop in oxidized dry hops and then cold crashing after a week. There is vacuum leaks because there is no negative pressure at racking time.

I am pretty careful about purging kegs with co2. I never open fermenters other than for racking. I don't secondary. I take that back. I did secondary the latest iipa. I placed the dry hops in a co2 purged keg and racked on top of them. This turned out oxidized, but I suspect because of the cold crash in the speidel before the rack onto dry hops.


I have a iipa in the works where I didn't cold crash. I am also force carbing at serving pressure. I also added dry hops during primary fermentaation. Gonna go sneak a taste right now after 24 hours at 5 psi. Bleh, it doesn't taste like carboard yet, no cabonation. Very cloudy from no cold crashing. will post back on how this turns out.

 

[tagz]

I eliminated oxidation from my list. And, after several successful beers with citra, mosaic, and centennial, I'm pretty sure my primary issue was hop type and quantity. I've used Ahtanum in smaller quantities with some success. Amarillo I will just avoid from now on. By the way, the problem got worse over time with me as well. I was typically pretty happy after sampling at the end of fermentation. After kegging and carbing, it was gross.

 

[grathan]

Hey that is good news tagz, you couldn't share a recipe and hop vendor so that I could try it out?

 

[tagz]

I've been getting most of my hops from Farmhouse Brewing Supplies. Although I have ordered from Grain to Glass recently as well. I like the 4 ounce packs, because it allows me to try out several strains.

Here's the grain-bill I've been using for the single hop beers I brewed to get to the root of the problem:

82% Pale Ale Malt
6% Aromatic
6% Caramel 40
6% Flaked Barley

OG ~1.050

Technically, they are not single hop beers, as I bitter with a small charge of Warrior (25 IBUs). But, Warrior is a clean bittering hop, and I was really trying to evaluate flavor. I started off really light handed on the flavor additions (because the bad batches made me gun-shy). They were 3 gallon batches and I used .5oz for a hopstand and .5 oz for dryhop. After the first few successful runs, I increased to the amounts. However, I have stuck to the 60 min, hopstand, and dryhop schedule because I liked the results. When using these small amounts, the dryhop flavor fades quickly, so I started adding a small dose of hops in the keg as well (tea ball). It keeps the flavor bright for a longer period of time.

All that is to say, I would recommend doing some small batch, single hop beers to see if hop variety might be the variable causing you the trouble. Based on the descriptions, I should like Amarillo and Ahtanum, but turns out... not so much. Or, I just got a bad batch.

 

[Francis]

So glad I found this thread, so I can vent. I'm having this EXACT issue with my IPAs and it's super Fn frustrating! Last week I bottled a black rye IPA (Wookey jack clone). It tasted amazing when I racked to secondary and on bottling day. The rye came through, hop flavor and aroma was awesome (double dry hopped with citra/Amarillo). I was really excited about this beer. I cracked one last night, 10 days in bottle, just to see how it's coming along and right away I noticed that smell. And of course the taste is right there with it. I no longer get the nice citrusy hop aroma or the rye maltiness. It just has a harsh aroma/taste - hard to explain the taste but it sounds like the same thing you're experiencing. Don't have this issue with my non-hoppy beers either. This is my 4th IPA I've brewed, all different recipes with different hops but ALL of them have ended up having this issue.

My first thought is its time to retire the bottling and start kegging. Seems like it would be a lot easier to limit the amount of contact with oxygen but you're kegging and having the same issue.

Last month I helped my friend brew his 1st all grain beer - NB dead ringer IPA. We used my equipment and process but his tap water (no water adjustments) and he kegged instead of bottled. It was one of the best home brews I've ever had. Didn't even have a hint of "that" off flavor. So maybe it's my water? I have a ward labs water report and use Brunwater to make adjustments and check my mash/sparge PH.

I might try store bought drinking water and brew a small batch. No more $60+ recipes until I get this sh*t figured out!

 

[mbbransc]

I'm glad I found this thread too. I started two threads a few weeks ago titled "fix my twang" and "where'd the hops go?" as I thought I had two separate issues. From reading here, it sounds like others are experiencing the same thing and maybe it's a single problem. I'm down to yeast troubles, water troubles, or bottling practices. I have an imperial IPA fermenting now that I added campden tablets to. I also switched to US-05 (two packs) to eliminate any human error in my starters. I fermented a little cooler than normal and gradually increased the temps. I'm planning to cold crash and rack to secondary for dry hopping. Then I'm going to cold crash again before bottling.

I hadn't thought about the carbonation levels though. I've had a tendency of over-estimating how much beer I'm going to end up with in my bottling bucket and as a result have over-carbed almost all of my IPAs. In fact, all except the ONE that I think turned out good. Maybe I'll start aiming a little lower on my CO2 volume as well.

I should know more sometime after the first of the year.

 

[bradpoff]

Just curious if anyone has changed their milling protocol during experimentation. Can over-milled grains or leaving them too long after milling and before using cause the off flavor reported here?

 

[tagz]

So glad I found this thread, so I can vent. I'm having this EXACT issue with my IPAs and it's super Fn frustrating! Last week I bottled a black rye IPA (Wookey jack clone). It tasted amazing when I racked to secondary and on bottling day. The rye came through, hop flavor and aroma was awesome (double dry hopped with citra/Amarillo). I was really excited about this beer. I cracked one last night, 10 days in bottle, just to see how it's coming along and right away I noticed that smell. And of course the taste is right there with it. I no longer get the nice citrusy hop aroma or the rye maltiness. It just has a harsh aroma/taste - hard to explain the taste but it sounds like the same thing you're experiencing. Don't have this issue with my non-hoppy beers either. This is my 4th IPA I've brewed, all different recipes with different hops but ALL of them have ended up having this issue.

My first thought is its time to retire the bottling and start kegging. Seems like it would be a lot easier to limit the amount of contact with oxygen but you're kegging and having the same issue.

Last month I helped my friend brew his 1st all grain beer - NB dead ringer IPA. We used my equipment and process but his tap water (no water adjustments) and he kegged instead of bottled. It was one of the best home brews I've ever had. Didn't even have a hint of "that" off flavor. So maybe it's my water? I have a ward labs water report and use Brunwater to make adjustments and check my mash/sparge PH.

I might try store bought drinking water and brew a small batch. No more $60+ recipes until I get this sh*t figured out!

Dead Ringer uses centennial exclusively. I would brew you next few batches with centennial. Since you know you like the hop, you can play with the other factors. Once you get that dialed in, try some other varieties as single hops beers. You might find that certain varieties are more prone to the off-flavor.

After further experimentation, I finally tossed the rest of my amarillo and a good amount of ahtanum. They both give off the harsh vegetal/herbal flavor that masks the other hop flavors. I haven't had any problems with citra and centennial, very clean fruity profile for both. Mosaic is tropical fruity at first, turns slightly herbal after a week and then finishes out citrusy. The herbal notes don't detract enough to make me avoid it.

Your problem may not be variety, but it's an easy variable to test with some small batch single hop beers. It was one of the last factors I tested, but what a relief it is to finally be able to brew hoppy beers!

 

[grathan]

While I haven't tried your recipe yet. I did try the IIPA i made without cold-crashing and the oxidized flavors were considerably subdued. I think to further reduce my oxidation I will need to use natural carbonation (yeast consume oxygen). I think something about big dry-hopped beers makes them incredibly sensitive to oxygen.