Beer loses hop aroma and then tastes vegi-ish. What's wrong?

[Thure]

Hi my Networks.

I brewed an american pale ale with first wort hopping and then late hopping (Hopbursting). After the beer's been on primary for a month I've kegged and force carbonated it.
When I pour the beer the flavor and aroma is nice and hoppy but after a few minutes the hop aroma and the nice hop flavor dissipates and then the beer tastes of 'green matter' like if you chew on a leaf or green grass. I have used all the hops before and have never had this experience before in my brews. Only time I've tasted this is in cask ale that's way past its prime.
What is the problem here and why does it do that? Is it because it reacts with the air or is there something else wrong? Can it be fixed with dry hopping?

The recipe for the beer is below-

Brewer: Thure
Batch Size: 20.00 l Style: American Pale Ale (10A)
Boil Size: 24.53 l Style Guide: BJCP 2008
Color: 8.5 EBC Equipment: 25 ltr. Nimbus - RS270
Bitterness: 48.0 IBUs Boil Time: 60 min
Est OG: 1.044 (11.0° P) Mash Profile: Single Infusion, Medium Body, Batch Sparge
Est FG: 1.009 SG (2.4° P) Fermentation: Ale, Single Stage
ABV: 4.6% Taste Rating: 30.0
Ingredients
Amount Name Type #
4.00 kg Pale Malt, Maris Otter (Thomas Fawcett) (5.9 EBC) Grain 1
30.0 g Cascade [5.5%] - First Wort Hops 2
10.0 g Centennial [11.0%] - Boil 60 min Hops 3
4.00 g Klarurt - fining (Boil 10 min) Misc 4
10.0 g Cascade [5.5%] - Boil 10 min Hops 5
10.0 g Citra [12.9%] - Boil 10 min Hops 6
1.00 tsp Yeast Nutrient (Boil 10 min) Misc 7
10.0 g Citra [12.9%] - Boil 1 min Hops 8
1 pkgs Safale American (DCL/Fermentis #US-05) Yeast 9

[spiderwrangler]

The hops are all fresh/well handled to the best of your knowledge?

[hoodie]

48 IBU's is a little high for a 1.044 beer (but not unprecedented), with a BU/GU of over 1. It could just be that your beer is out of balance and there's not enough malt character or residual sweetness to back up your hop bill. Citra can be a bit overwhelming in large quantities, especially in a low gravity beer. Let it age a bit.

[Thure]

All hops are pellet hops from a vacum sealed silverlined bag and stored in the freezer at -20C

[baltobrewer]

Hmm. Odd. Most grassy/vegetal in your scenario would come from dry hopping for too long, or from using wet hops. If they're pellets from a vac sealed bag, then thats obviously not the issue. Don't know what Klarurt is. Is that some sort of Irish Moss-ish thing? Perhaps that could be the weak link...

[brewinhard]

First wort hopping can sometimes be overdone especially if you already have a lot of late hop additions in there. Although it can provide a smooth hop flavor (some say akin to a 20 min addition), it can sometimes be a bit too much, especially in such a low gravity beer 1.044 with no specialty malts to back up the hop flavor. Just a thought.

I have observed this when using too much FWH in an IPA I brewed with minimal malts and lots of flavor hop additions. It left behind a very astringent, grassy, flavor. Could also be your water profile as well. Might want to check that out too!

[Thure]

Our water is ground water from a single source and has been consistent for a very long time, so don't thing it's the water. I've brewed a ton of IPA/APA's with it because it has the right profile for that and for the most part they have come out fine (except for a few infected ones).

"Klarurt" is carrageenan that is the active stuff in Irish Moss. I've been using it for years in all my beer including Sparkling Ale and Cali.common without it ever showing in taste.


The thing is that the beer both smells and tastes just like a hoppy pale just when it's poured, but that disappears after like five minutes and just leaves that green taste like a beer with dry hopping left in the fermenter for way too long.

The base beer in it self has a pretty nice bready/biscuity body from the Maris Otter malt, but maybe it could be the first wort hops. It gives 24 BU out of the 48, so that might be a tad too much.
Any further thoughts on that?

Thanks for the help, guys!

[BDawg]

I have a similar recipe that uses twice as much flavor and aroma hops and it does not suffer from the grassiness you describe.

Try going with a smaller amount of a cleaner but higher alpha hop for FWH. Something like 15g of 12% Magnum. (Or, you could simply change it to an even smaller traditional bittering addition - 10g @60.)