Post-Carbonated Bitterness Developing

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ShadySquirrel

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Most of my batches become bitter in about 10 days after finished carbonating. This has happened with different recipes, both bottle conditioned and forced carb in a keg. The batches start fresh, but without fail during the second week after finished develop a harsh upfront bitterness. These are all IPA recipes.

I’m not doing a fully closed transfer, but as minimal oxygen and splashing as I can. Presently, after cold crashing, racking straight from my Anvil fermenter (primary/only) into the purged keg carefully. I do my best to avoid too much trub or hop material to make it into my keg. I have also incorporated ascorbic acid into my mash as a means to minimize oxidation, but no luck. Once I started kegging I hoped this would be resolved but still occurring.

If anyone has experienced this, please let me know what I can do to increase my fresh shelf life. Is this merely just oxidation from the transfer, leaving my only choice to go full closed system?
 
I’m not sure exactly what you’re seeing, but a couple of things come to mind.
The first is carbonic bite from the carbonation itself. To my taste, it seems to amplify the bitterness. With more time the bitterness of my hops mellows out.

The other thing I’ve seen is that there is a bitterness/green-ness during the beginning of cold crashing. I don’t see it if the beer is just quick-chilled, or after it clears up in about 5 days.

My west coast pale ales need at least 4 weeks in the bottle before to get into the ‘really good‘ zone.
 
You asked about transfering.
It damn well could be. When you rack your beer, be absolutely certain you have no leaks in the racking equipment. A hairline crack in an auto siphon tube can be a hard to spot culprit. Often enough, its a leak where one's flexible tubing connects to his racking cane. Wherever the leak, if you have one, it WILL induce O2 into the beer as the siphon pulls air through the leak. Bad news for brewers.
 
You asked about transfering.
It damn well could be. When you rack your beer, be absolutely certain you have no leaks in the racking equipment. A hairline crack in an auto siphon tube can be a hard to spot culprit. Often enough, its a leak where one's flexible tubing connects to his racking cane. Wherever the leak, if you have one, it WILL induce O2 into the beer as the siphon pulls air through the leak. Bad news for brewers.

I don’t think I have any leaks in tubing, not using an auto siphon. Going from the faucet at the bottom of the Anvil fermenter, with a long tube to the bottom of the keg.. Keg is purged before, after and burped..
 
Harsh bitterness is sometimes associated with high mash pH due to excess residual alkalinity in your brewing water. This comes out with pale beers, not so much with dark ones. What is your water and how do you treat it, if you do at all?
 
Harsh bitterness is sometimes associated with high mash pH due to excess residual alkalinity in your brewing water. This comes out with pale beers, not so much with dark ones. What is your water and how do you treat it, if you do at all?
I’ve been using distilled water, and treating to match my target profiles. Most typically either a NEIPA or hoppy ale profiles.

I had a previous batch with a high pH; so I have been incorporating acidulated malt to keep the pH in check..
 
Sounds like you're ahead of that issue, then. That was my epiphany years ago when I started brewing with my well water. It has very high alkalinity and of course as a new brewer I had no clue about that. Sorry I couldn't offer some other helpful tidbit.
 
You say different styles originally but then just recently stated..
I’ve been using distilled water, and treating to match my target profiles. Most typically either a NEIPA or hoppy ale
Are last 10 beers all heavily hoped beer styles? If so it’s very possible you’re experiencing hop burn (especially if you dryhop during fermentation or at temps over 60*f). I have a pretty good hand on hopburn but sometimes even with best practices, hop burn can occur. You can taste it while in the fv but once the carb is set it will be perceived as it is more bitter. After about 3 weeks it should subside
 
You say different styles originally but then just recently stated..

Are last 10 beers all heavily hoped beer styles? If so it’s very possible you’re experiencing hop burn (especially if you dryhop during fermentation or at temps over 60*f). I have a pretty good hand on hopburn but sometimes even with best practices, hop burn can occur. You can taste it while in the fv but once the carb is set it will be perceived as it is more bitter. After about 3 weeks it should subside

Not exactly different styles, I said these are all IPA recipes. I’ve been focusing on standard American IPAs and Hazy NEIPAs.

But yes, most are heavily hopped, particularly the NEIPA. I have definitely been going overkill on the hazys and my current in the keg that’s a standard IPA but heavy hopped. All are dry hopped and fermenting around 68-70 degrees. I’ve been taking steps to try and reduce the amount of hop matter hanging out during fermentation by bagging and removing.

I have never heard of “hop burn” yet, so thanks for that. I will look more into that, is the best way to fix that reducing the amounts?
 
The OP is interesting. Sure you are not confusing post-carbonated bitterness with oxygenation?

Oxygenation was my first thought as well. I’ve tried to take steps to reduce but I’m not on a closed system. I just bought some more stuff to do a pressurized transfer so hoping to reduce more.

To me the strangest part is they usually start out really good once fully carbed, then a few weeks later it drastically changes. I know it will change a bit as it matures, but in a matter of days can really swing.
 
I have never heard of “hop burn” yet, so thanks for that. I will look more into that, is the best way to fix that reducing the amounts?
Hop burn is caused by polyphenols that are in suspension. It causes a spicy bitterness that kinda has a burning sensation. During fermentation, yeast will actually bind the polyphenols with proteins and this will causes them to remain in suspension longer. Temperature of the dryhop has an effect on this too because hops contain enzymes that can cause a refermentation called hop creep. This refermenation causes additional hopburn.

reducing the dryhop size can cause less hopburn due to less polyphenols, but dryhop sizes isn’t the best way to manage it (for example I just kegged a double NEIPA yesterday that was dryhoped with 10 oz of AUS/NZ hops in a 5 gallon batch, 2 days before and I don’t even have a touch of hopburn.

Best ways to reduce it;

1) make sure you transfer trub free wort to the FV

2) do not dryhop while the yeast are actively fermenting the beer

3) once your at a stable FG, crash the beer to 50s or below to drop the majority of the yeast out of suspension.

4) then dryhop at 60 or below (yeast dependent, some ale yeast can still be quite active at 60). Ive personally aimed to dryhop at 56-58*f for 3 days or less.

5) this all should be done with the best anti o2 practices you can achieve on your system
 
Oxygenation was my first thought as well. I’ve tried to take steps to reduce but I’m not on a closed system. I just bought some more stuff to do a pressurized transfer so hoping to reduce more.

To me the strangest part is they usually start out really good once fully carbed, then a few weeks later it drastically changes. I know it will change a bit as it matures, but in a matter of days can really swing.

Meaning loss of aroma or loss of perceived bitterness?
 
To me the strangest part is they usually start out really good once fully carbed, then a few weeks later it drastically changes. I know it will change a bit as it matures, but in a matter of days can really swing.
now reading this, I feel you are experiencing oxidation. Hopburn usually starts out bad initially and is heightened by carbonation but after 14-21 days it typically gone. If not gone, much much better
 
I'm still not really clear on the specifics of OP's process for transferring from fermentor to keg, but I think moving to a closed transfer system will very likely yield improvements.

The way the problem is described sounds almost exactly as I would have described my IPAs a few years ago. In fact, I'm sure I could dig up a thread where I asked the same question, almost verbatim.

I have noticed that when you dry hop beers without being very careful about oxygen (especially during packaging), the desirable aromas die pretty much immediately, and you're left with this residual flavor component from the dry hops that I would definitely describe as a sort of unpleasant bitterness. It may not render the beer undrinkable but definitely qualifies as an "off flavor." I noticed this a lot when I would split 10gal batches and dry hop one half but not the other. A short time into the life of the beer, the non-dry-hopped versions were better 100% of the time because they didn't have this annoying bitterness developing.

Another thing to consider - which I don't feel gets mentioned enough - is to check the freshness of the hops you're using, especially for dry hopping. I think lots of local homebrew shops use highly questionable practices for handling their stock of hops, and you can sometimes end up with hops that have been sitting at the back of a freezer for 2 years and smell like cheese. Hops are expensive, so the shops are really reluctant to throw them in the trash, so you need to be careful. If you dry hop with stale hops you will definitely end up with disappointing aroma and an unpleasant bitter-like taste.
 
Hop burn is caused by polyphenols that are in suspension. It causes a spicy bitterness that kinda has a burning sensation. During fermentation, yeast will actually bind the polyphenols with proteins and this will causes them to remain in suspension longer. Temperature of the dryhop has an effect on this too because hops contain enzymes that can cause a refermentation called hop creep. This refermenation causes additional hopburn.

reducing the dryhop size can cause less hopburn due to less polyphenols, but dryhop sizes isn’t the best way to manage it (for example I just kegged a double NEIPA yesterday that was dryhoped with 10 oz of AUS/NZ hops in a 5 gallon batch, 2 days before and I don’t even have a touch of hopburn.

Best ways to reduce it;

1) make sure you transfer trub free wort to the FV

2) do not dryhop while the yeast are actively fermenting the beer

3) once your at a stable FG, crash the beer to 50s or below to drop the majority of the yeast out of suspension.

4) then dryhop at 60 or below (yeast dependent, some ale yeast can still be quite active at 60). Ive personally aimed to dryhop at 56-58*f for 3 days or less.

5) this all should be done with the best anti o2 practices you can achieve on your system


Would I still be able to do priming for CO2 after doing step 1-4, sounds like I won't have much active yeast remaining?
 
Would I still be able to do priming for CO2 after doing step 1-4, sounds like I won't have much active yeast remaining?
Unless you have a centrifuge, there still plenty of yeast left. If you’re concerned you can always added some CBC-1 yeast as you bottle.

Bottling heavily dryhoped ipas is not advised to be honest. Unless you have strict practices, and even then, oxidation I’d likely to occurs. So definitely review the best practices for bottling heavily hopped beers
 
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