About IPA flavour， like grass，acetaldehyde

[xayz110]

I want to ask a question. I recently made 22L session ipa. I didn’t boil hops. I cooled 26L wort to 80℃ and whirlpooled 100g simcoe pellets（T90）+ 100g mosaic.pellets（T90）

I used us05 yeast. After fermentation, I confirmed that there was no abnormal odor. And I dry-hopped 50g Simcoe pellets（T90）+ 30g Centennial pellets（T90） + 30g Mosaic pellets（T90）+ 1oz Citra pellets（T45）. After 4 days of dry-hopped and 2 days of cold sedimentation, it was forced carbonization in keg.

Today is the fifteenth day of entering keg. I drank it a little last night. It tasted good at low temperature, but when the temperature of the beer warmed to 20℃, there was a grassy smell, similar to acetaldehyde.

So,What is the problem? This problem has happened many times.

 

[lonelymtn]

Are you dry hopping at or near room temperature, or closer to serving temperature? Personally, I have noticed more grassy flavors coming out of dry hopping when performing it at cold temperatures, versus more favorable flavors and aromas when doing it closer to fermentation temperatures.

As far as acetaldehyde, that comes across to me more like green apples than grassy. You may just be getting grassy flavors due to your dry hopping rate. If my math is correct, you are dry hopping at over 6g/L, which is near the oil saturation rate (8g/L) according to research performed by Tom Shellhammer. Are you dry hopping in one big charge, or splitting it up?

 

[xayz110]

Are you dry hopping at or near room temperature, or closer to serving temperature? Personally, I have noticed more grassy flavors coming out of dry hopping when performing it at cold temperatures, versus more favorable flavors and aromas when doing it closer to fermentation temperatures.

As far as acetaldehyde, that comes across to me more like green apples than grassy. You may just be getting grassy flavors due to your dry hopping rate. If my math is correct, you are dry hopping at over 6g/L, which is near the oil saturation rate (8g/L) according to research performed by Tom Shellhammer. Are you dry hopping in one big charge, or splitting it up?

I dry hopping at room temperature(18-20℃)，and twice dry hopping。

 

[Nosybear]

I want to ask a question. I recently made 22L session ipa. I didn’t boil hops. I cooled 26L wort to 80℃ and whirlpooled 100g simcoe pellets（T90）+ 100g mosaic.pellets（T90）

I used us05 yeast. After fermentation, I confirmed that there was no abnormal odor. And I dry-hopped 50g Simcoe pellets（T90）+ 30g Centennial pellets（T90） + 30g Mosaic pellets（T90）+ 1oz Citra pellets（T45）. After 4 days of dry-hopped and 2 days of cold sedimentation, it was forced carbonization in keg.

Today is the fifteenth day of entering keg. I drank it a little last night. It tasted good at low temperature, but when the temperature of the beer warmed to 20℃, there was a grassy smell, similar to acetaldehyde.

So,What is the problem? This problem has happened many times.

It's the hops themselves likely. "Grassy" is a common descriptor used when describing dry-hopped beer, particularly if the beer is hopped after fermentation is complete. It's not likely that what you describe is acetaldehyde.

 

[lonelymtn]

Further, acetaldehyde is produced as an intermedite compound during fermentation, but is almost always fully converted to alcohol by the yeast. If you are experiencing a green apple-like flavor in your beers that aren't dry hopped as well, it may point to unhealthy fermentation. If it is only "grassy" when you dry hop, then it is likely due to your hopping schedule, as @Nosybear indicates.

For beers that I dry hop twice, I usually split the total bill in to 2/3 and 1/3. The former goes in at the tail end of fermentation (within 5-7 points of FG), and the latter a couple of days later. I never leave my beer on the dry hops for more than 7 days in total (usually less).

 

[Mark D Pirate]

@xayz110
For a session IPA you can reduce your hopping rate quite a lot here , can i ask why no boil addition for bitterness ?
Are you getting nice fresh hops and storing them cold ?

 

[xayz110]

It's the hops themselves likely. "Grassy" is a common descriptor used when describing dry-hopped beer, particularly if the beer is hopped after fermentation is complete. It's not likely that what you describe is acetaldehyde.

Thanks，maybe It's not acetaldehyde，i think it's "Grassy". Is this taste due to dry-hopping ?

 

[xayz110]

Further, acetaldehyde is produced as an intermedite compound during fermentation, but is almost always fully converted to alcohol by the yeast. If you are experiencing a green apple-like flavor in your beers that aren't dry hopped as well, it may point to unhealthy fermentation. If it is only "grassy" when you dry hop, then it is likely due to your hopping schedule, as @Nosybear indicates.

For beers that I dry hop twice, I usually split the total bill in to 2/3 and 1/3. The former goes in at the tail end of fermentation (within 5-7 points of FG), and the latter a couple of days later. I never leave my beer on the dry hops for more than 7 days in total (usually less).

Thanks,I'll try this in next beer

 

[xayz110]

@xayz110
For a session IPA you can reduce your hopping rate quite a lot here , can i ask why no boil addition for bitterness ?
Are you getting nice fresh hops and storing them cold ?

I want to reduce the bitterness，so i didn't boil hops.
The hops maybe fresh,but i'm not sure.

 

[Hogarthe]

You said it was a session IPA. I find a lot of session ipas to be a bit grassy I think it is too much hops in a light beer. There just isn't enough malt there to balance it so you get leafy flavors.

 

[xayz110]

You said it was a session IPA. I find a lot of session ipas to be a bit grassy I think it is too much hops in a light beer. There just isn't enough malt there to balance it so you get leafy flavors.

Thanks