Grassy/Vegetable Off flavor Diagnosis

[Bennywisest]

I was wondering if anyone can help me identify an off flavor in a recent American Pale Ale I brewed. It is a very grassy kind of vegetable off-flavor. I've read of this happening with dry hopping for too long and from using homegrown hops. MY recipe is below, I did not dry hop and the hops all smelled fresh. I planned on doing a 30 minute hop stand at 180 F but overcooled my wort and started the hop stand at 120F. Did this lower temp add the grassy flavors? After the hop stand I whirlpooled the wort and racked into my fermentor.
For water I use bottled deer park water. I have never had this off flavor before, so thanks in advance for any help.

Recipe Specifications
--------------------------
Boil Size: 8.42 gal
Post Boil Volume: 6.92 gal
Batch Size (fermenter): 5.50 gal
Bottling Volume: 5.00 gal
Estimated OG: 1.052 SG
Estimated Color: 5.9 SRM
Estimated IBU: 49.3 IBUs
Brewhouse Efficiency: 68.00 %
Est Mash Efficiency: 82.2 %
Boil Time: 60 Minutes


Ingredients:
------------
Amt Name Type # %/IBU
9 lbs Pale Malt (2 Row) US (2.0 SRM) Grain 1 76.6 %
2 lbs Munich Malt - 10L (10.0 SRM) Grain 2 17.0 %
8.0 oz Caramel/Crystal Malt - 10L (10.0 SRM) Grain 3 4.3 %
4.0 oz Honey Malt (25.0 SRM) Grain 4 2.1 %
0.50 oz Centennial [9.70 %] - Boil 60.0 min Hop 5 14.9 IBUs
1.25 oz Centennial [9.70 %] - Boil 15.0 min Hop 6 18.5 IBUs
1.00 oz Saaz [3.20 %] - Boil 15.0 min Hop 7 4.9 IBUs
1.00 tsp Irish Moss (Boil 10.0 mins) Fining 8 -
1.00 oz Saaz [3.20 %] - Boil 5.0 min Hop 9 2.0 IBUs
1.25 oz Centennial [9.70 %] - Steep/Whirlpool 30.0 min Hop 10 7.2 IBUs
1.00 oz Saaz [3.20 %] - Steep/Whirlpool 30.0 mi Hop 11 1.9 IBUs
1.0 pkg California Ale (White Labs #WLP001) [35. Yeast 12 -

 

[Bennywisest]

Just to clarify. All hops added were pellets, purchased from my LHBS and stored in my fridge until use. I have never had problems with freshness of hops purchased there, and I am very careful about keeping the hops away from light (store in paperbags in fridge).

 

[zeptrey]

I was wondering if anyone can help me identify an off flavor in a recent American Pale Ale I brewed. It is a very grassy kind of vegetable off-flavor. I've read of this happening with dry hopping for too long and from using homegrown hops. MY recipe is below, I did not dry hop and the hops all smelled fresh. I planned on doing a 30 minute hop stand at 180 F but overcooled my wort and started the hop stand at 120F. Did this lower temp add the grassy flavors? After the hop stand I whirlpooled the wort and racked into my fermentor. For water I use bottled deer park water. I have never had this off flavor before, so thanks in advance for any help. Recipe Specifications -------------------------- Boil Size: 8.42 gal Post Boil Volume: 6.92 gal Batch Size (fermenter): 5.50 gal Bottling Volume: 5.00 gal Estimated OG: 1.052 SG Estimated Color: 5.9 SRM Estimated IBU: 49.3 IBUs Brewhouse Efficiency: 68.00 % Est Mash Efficiency: 82.2 % Boil Time: 60 Minutes Ingredients: ------------ Amt Name Type # %/IBU 9 lbs Pale Malt (2 Row) US (2.0 SRM) Grain 1 76.6 % 2 lbs Munich Malt - 10L (10.0 SRM) Grain 2 17.0 % 8.0 oz Caramel/Crystal Malt - 10L (10.0 SRM) Grain 3 4.3 % 4.0 oz Honey Malt (25.0 SRM) Grain 4 2.1 % 0.50 oz Centennial [9.70 %] - Boil 60.0 min Hop 5 14.9 IBUs 1.25 oz Centennial [9.70 %] - Boil 15.0 min Hop 6 18.5 IBUs 1.00 oz Saaz [3.20 %] - Boil 15.0 min Hop 7 4.9 IBUs 1.00 tsp Irish Moss (Boil 10.0 mins) Fining 8 - 1.00 oz Saaz [3.20 %] - Boil 5.0 min Hop 9 2.0 IBUs 1.25 oz Centennial [9.70 %] - Steep/Whirlpool 30.0 min Hop 10 7.2 IBUs 1.00 oz Saaz [3.20 %] - Steep/Whirlpool 30.0 mi Hop 11 1.9 IBUs 1.0 pkg California Ale (White Labs #WLP001) [35. Yeast 12 -

Could also be DMS, dimethyl sulfide. Increase your boil time to 90 minutes to help. Also while whirlpooling leave the lid off so vapors escape the kettle.

 

[Bennywisest]

I don't think it is DMS. I had that probelm on a brew before and I'm very careful about getting rid of precursors. I usually do a hard boil and don't use the lid on my brewpot at all.

The flavor is more grassy, then vegetable I guess. Kind of a tongue coating bitterness to it. Its not quite a soapy taste though.

 

[zeptrey]

I don't think it is DMS. I had that probelm on a brew before and I'm very careful about getting rid of precursors. I usually do a hard boil and don't use the lid on my brewpot at all. The flavor is more grassy, then vegetable I guess. Kind of a tongue coating bitterness to it. Its not quite a soapy taste though.

3 oz of Saaz would do it probably too.

 

[zeptrey]

3 oz of Saaz would do it probably too.

Sorry to reply to my reply but especially with one of those ounces of Saaz in the boil. That would most likely be your culprit.

 

[Bennywisest]

Thanks Zeptrey! Do you think it was from hopstanding with the Saaz? Just too much of it? Or maybe it was stored poorly? I just don't want to make the mistake again. Thanks!

 

[zeptrey]

Thanks Zeptrey! Do you think it was from hopstanding with the Saaz? Just too much of it? Or maybe it was stored poorly? I just don't want to make the mistake again. Thanks!

I'd say too much of it. Late hopping with 3 ounces of it is a bit much for a 5 gallon batch. Saaz has a herbal aroma to it anyway. 3 ounces of it late like that will give you some definite grassy flavor. Centennial to me gives some herbal/floral flavor too..but that's me. So both of those in the amounts especially the Saaz probably did it.

All in all, it looks like an awesome beer. Did the brew come out a little dry or did the honey and crystal malt come through well?

 

[Bennywisest]

The malt body came through quite nice. I was looking for a pale ale with a little more body and sweetness for the winter. I mashed at 152F, but think if I used this malt base again I might take it down to 148-150. It is tasty (apart from the hop off-flavor) just a bit sweet for my personnel preference.

 

[zeptrey]

The malt body came through quite nice. I was looking for a pale ale with a little more body and sweetness for the winter. I mashed at 152F, but think if I used this malt base again I might take it down to 148-150. It is tasty (apart from the hop off-flavor) just a bit sweet for my personnel preference.

I wonder if you used US05 if it'd attenuate a little more and clean it up a bit. What was the final gravity?

I haven't used the honey malt before I don't think I've even tried at the LHBS. I saw that and was curious of how it's used. I'll have to read up on that.

 

[Bennywisest]

I'll post back tonight with FG (I don't have my notes with me right now). A friend of mine got me into Honey malt. It adds a lasting sweetness, but very easy to overdo. I usually only add a touch of it when I use it. It smells like fruity pebbles when being milled. :fro:

 

[Bennywisest]

FG was 1.011

 

[zeptrey]

FG was 1.011

Maybe pitch two packs of US05 on it and mash at a little lower temp. That's the cool thing about this a few minor tweaks make a world of difference. Or take out the honey malt and keep the mash temp.