Off Flavor after Dry Hopping?

[Forddj1]

Taste tested 2.5 gallon pale ale after primary and it was delicious (warm and flat but still good). No off flavors detectable.

Decided to dry hop because I guess I wanted to push my luck.

Dry hopped and cold crashed in the secondary with 0.5oz YCHHops Falconer's Flight 11.8% alpha for 72 hours, racked to keg after 5 days.

Tasted during racking and there was a distinct grass? hay? cardboard? flavor right in the middle of the taste. Some research would point to improperly stored hops, the high AA in the hops, or oxidation. No concrete explanation.

Can anyone explain why this may have happened? Any fixes? Do I dump? Thanks for your help.

Some additional notes:
-Noticed some white matter in the bottom of the secondary carboy, but I think this is protein from cold crashing settling at the bottom.
-Hops were bought two weeks ago, some were used in the brew, and then stored in a ziploc bag in the fridge.
-Used a fine mesh bag that was "squeezed" coming out of the neck of the carboy.

 

[Northern_Brewer]

Cardboard sounds like oxidation - of the beer rather than ingredients. Grass and hay might also point to some kind of infection.

Two weeks in the fridge shouldn't have hurt the hops too much, but at this time of year any northern hemisphere hops will be a year old at least, and you never know how they've been kept the rest of the year. They could be a bit stale and dull, but it would more likely show up as just that - a bit dull, rather than actively contributing off flavours.

Not sure there's a lot you can do right now - either sit tight and hope it conditions its way out of trouble, or you're dumping it. The grass and hay might disappear, but cardboard is more of a one-way deal...

 

[Beerdrinker85]

Taste tested 2.5 gallon pale ale after primary and it was delicious (warm and flat but still good). No off flavors detectable.

Decided to dry hop because I guess I wanted to push my luck.

Dry hopped and cold crashed in the secondary with 0.5oz YCHHops Falconer's Flight 11.8% alpha for 72 hours, racked to keg after 5 days.

Tasted during racking and there was a distinct grass? hay? cardboard? flavor right in the middle of the taste. Some research would point to improperly stored hops, the high AA in the hops, or oxidation. No concrete explanation.

Can anyone explain why this may have happened? Any fixes? Do I dump? Thanks for your help.

Some additional notes:
-Noticed some white matter in the bottom of the secondary carboy, but I think this is protein from cold crashing settling at the bottom.
-Hops were bought two weeks ago, some were used in the brew, and then stored in a ziploc bag in the fridge.
-Used a fine mesh bag that was "squeezed" coming out of the neck of the carboy.

Since you just racked the beer, give it time. I had many grassy offlavor after dry hopping and it goes away in like 5-10 days after kegging with some hops.

 

[kh54s10]

I never judge a beer on the flavor at packaging time. I find that some beers change dramatically between the time of packaging and when they are fully carbonated. Though usually the sample tastes OK and gives you an idea of what the final outcome will be.

 

[PADave]

Next time eliminate the secondary.

 

[Qhrumphf]

Was your 2.5 gallon beer racked into a 5+ gallon secondary? Because that'd be your problem.

 

[Gadjobrinus]

I'd agree oxidation, and the grassiness is for me, almost classically, too long a dry hop period.

However you're nowhere near where some of the brewers who take it out to a few weeks or more, so it's very doubtful it's that. I'm not sure on the quality of the hops as an issue - I presume these smelled pleasant before tossing them in.

I think alot comes down to the approach. I begin my hop slurry "dry hop" as primary nears completion, not after - eliminating the oxidation concern.

And they only get 3 days, then racked off. Ensuring no tannin and other unwanted extraction. Because of of the slurry, there is no time spent in getting pellets to break down and begin yielding up their oils, or an even longer period when using whole hops. If I could recirc, I would.

Both of these don't mean these are the issues, of course. This is just the approach I learned from Matt Brynildson while at Goose Island, and it's worked very well for me.

The only other thing I can think of is variety. I've never personally used high-alpha hops for dry hopping, although I know a ton of people do. Have you had success with this variety before?

 

[thehaze]

I'd agree oxidation, and the grassiness is for me, almost classically, too long a dry hop period.

However you're nowhere near where some of the brewers who take it out to a few weeks or more, so it's very doubtful it's that. I'm not sure on the quality of the hops as an issue - I presume these smelled pleasant before tossing them in.

I think alot comes down to the approach. I begin my hop slurry "dry hop" as primary nears completion, not after - eliminating the oxidation concern.

And they only get 3 days, then racked off. Ensuring no tannin and other unwanted extraction. Because of of the slurry, there is no time spent in getting pellets to break down and begin yielding up their oils, or an even longer period when using whole hops. If I could recirc, I would.

Both of these don't mean these are the issues, of course. This is just the approach I learned from Matt Brynildson while at Goose Island, and it's worked very well for me.

The only other thing I can think of is variety. I've never personally used high-alpha hops for dry hopping, although I know a ton of people do. Have you had success with this variety before?

It does not matter what AA% your dry hop hops have. I have dry hopped many times with El Dorado, Eureka, Citra, Columbus, Chinook, Simcoe, Mosaic, Azacca, Denali, etc. and many times over 8 oz per 5-6 gallons and no grassy flavours were registered.

Also, I always dry hop when the beer is warmer and not your typical " do it right " at 60-64 F.

And that hops is not grassy.

 

[Agtronic]

It's very difficult to diagnose issues like these using a description provided online, I'm afraid.

From your description of dryhop quantity and process, it doesn't sound like you're doing anything "wrong". That is a relatively small amount of hops for a dry hop charge in a pale ale. Certainly not enough to make a significant (off)flavour impact in my opinion.

One thing I have noticed is the minute I start moving my beer from vessel to vessel it starts to change, for the worst, regardless of how careful I am to limit oxygen exposure. Perhaps this is what you are noticing too.

 

[dn151864]

Was your 2.5 gallon beer racked into a 5+ gallon secondary? Because that'd be your problem.

Why would that be a problem? Just curious...

 

[Mr_McGibblets]

Since you just racked the beer, give it time. I had many grassy offlavor after dry hopping and it goes away in like 5-10 days after kegging with some hops.

I never judge a beer on the flavor at packaging time. I find that some beers change dramatically between the time of packaging and when they are fully carbonated. Though usually the sample tastes OK and gives you an idea of what the final outcome will be.

This. My last batch was a Citra IPA (extract kit from MoreBeer). I dry-hopped for 4 days in the keg before applying C02 and it too had a grassy/vegetal taste. But it started to dissipate over time. By week two, it was acceptable (to me), and by week four, it was superb -- all grassy/vegetal flavors were totally gone (again, to me).

 

[Ed-Wort]

Why would that be a problem? Just curious...

It is because if you don't purge the 5 gal with CO2 before you transfer it, you will have 2.5+ gal of empty space that has O2 in it, thus oxidation of the beer.

 

[stodds]

Why would that be a problem? Just curious...

beaten to the the punch. . . Deleted duplicate of Ed's post above.

 

[Brauer]

It's a problem because you introduced you beer into an oxygen rich environment. That's why most people avoid secondary now. If you do a secondary I recommend purging the carboy/bucket with c02 first.

About the grassy flavor. I had a beer that tasted grassy. It had a huge amount of late hops and lots of dry hops. I fined it with geatin and it cleaned up the flavor a lot.

Here is a step by step

Don't dump it!!
Cheers

http://www.bertusbrewery.com/2012/06/how-to-clear-your-beer-with-gelatin.html

 

[andrewmaixner]

I have never been able to reproduce any "grassy" flavor from extended hop contact time. I throw bags of pellet hops into my kegs and never remove them till it's empty, whether being stored at room temp for a month or a day before going on tap.

I also try to minimize oxygen by purging the keg before and after transfering, and adding sugar (whether transferring to a secondary or a keg) so that the yeast will reactivate and theoretically use up any dissolved oxygen.

 

[LKABrewer]

Any time you cold crash in a carboy/bucket, it will pull in O2. As the liquid cools, it absorbs more gasses into solution. Unless you are cold crashing under co2 pressure, you are oxidizing your beer. Consider dry hopping and cold crashing in a keg under co2 pressure.

 

[aaron3598]

O2 in the 2.5 gallons of unused head space. Even if purged with co2 there can be some o2 left to cause oxidation.

 

[fatnhappy]

I have had off flavors when dry hopping while the wort is cold. I get better results when dry hopping at ferment temps. The yeast is still active and able to scrub out a lot of those flavors

 

[thehighepopt]

Why would that be a problem? Just curious...

I believe because 2.5gal in a 5gal secondary leaves a lot of space with oxygen in it. In secondary, you don't have (much) fermentation so the oxygen isn't being pushed out by carbon dioxide leaving lots of time for oxygen to interact with your beer.

 

[Qhrumphf]

Yes, oxidation is the reason for reduction of secondary headspace or eliminating it entirely. As the OP describes characters I'd apply to oxidation, and an unusual batch size, first place my mind goes is too small batch in too big vessel. Now if his 2.5 gals went into a 3 gal carboy, then it could still be oxidation, but likely not as severe.

 

[stonebrewer]

+1 to the too much headspace theory. This is why I went to fermenting in 5G kegs that I spund and keep under pressure. The yeast will utilize all the oxygen and you are left with an anaerobic state in which your beer will not oxidize. Push to a serving keg that has been water flushed of all oxygen and Bob's your uncle!

 

[vosperp]

I was taught not to squeeze the hop bag. But per the other suggestions, I would carbonate and let it condition for a couple of weeks before judging if its drinkable. Some of those flavors may dissipate.

 

[TheBrewBrotha]

I would eliminate secondary altogether on future batches unless planning to age a beer for quite some time. I would still package this beer as the dry hop notes may fade out but it sounds like oxidation from hops which may have been from freezing in a ziplock. Have noticed the aroma and color of my hops aged better once I've started vacuum sealing them then freezing

 

[rob6239]

Something could have gotten infected, but from my limited experience; Cardboard = Oxygen

 

[stodds]

From the BJCP study guide, troubleshooting section, written by Scott Bickham:

Acetaldehyde
This compound has the taste and aroma of fresh-cut green apples, and has also been compared to grass,
green leaves and latex paint. It is normally reduced to ethanol by yeast during the secondary
fermentation, but oxidation of the finished beer may reverse this process, converting ethanol to
acetaldehyde. Elevated levels are generally present in green beer or if the beer is prematurely removed
from the yeast. It can also be a product of bacterial spoilage by Zymomonas or Acetobacter.
Background levels of acetaldehyde can be tasted in Budweiser due to the use of beechwood chips to
drop the yeast before it can be reduced to ethanol.
This can also be the result of inadequate wort oxygenation, though the resultant yeast byproducts are
normally metabolic intermediates they can remain after fermentation in some cases.​

One takeaway: Unless you've removed the yeast altogether (unlikely) it may get better with time.

 

[DevsRevs]

I regularly dry hop in the keg with a minimum of 6 oz of hops with high AA like this last batch I did 3 oz of mosaic and 3 oz of Galaxy and it never produces an off flavor, even down to the tap out stage. However if don't allow it to condition for a week at 65-68 degrees it doesn't allow the full effect of the dry hopping stage to produce all the floral notes it can create. Cardboard flavor is normally a product of oxidization for sure but I'd still allow a few days of being carbonated before determining the batch is shot. I'm a firm believer that beer matures and gasses a lot of off flavors after about 2 weeks in the keg. Just pull on your pressure release pin once a day for a second or two for a week to allow those gasses to escape the keg.

 

[malhal]

"Dry hopping is another common way of introducing oxygen to a beer. Some brewers take the trade-off in some aroma loss in order to dry hop during active fermentation, and thus have the yeast “scrub” the oxygen away."
https://www.brewshop.co.nz/blog/oxygenation/

I lost so many brews to oxidation this way but since I've changed to adding the double sized dose of dry hops on day 1 when fermentation has begun the problem is solved, no more grassy. I even leave the hops in for the full week.

 

[snarf7]

It is because if you don't purge the 5 gal with CO2 before you transfer it, you will have 2.5+ gal of empty space that has O2 in it, thus oxidation of the beer.

That sounds like the answer to me and a good case for why most people don't bother with a secondary

 

[kh54s10]

Almost 2 year old thread. But, I don't purge, I have dry hopped in the keg after all fermentation was finished. Siphon transferred. 2 ounces of hops in the keg that lasted over a month. No problem with oxidation or grassy. YMMV.