Oxygen exposure during dry hopping

[osu6251]

Currently fermenting a 90 minute iPA clone, 5 gallon batch. I have a 7 gallon fermentor and plan to plan to dry hop in the primary, will not be transferring to a secondary. Does opening the primary, releasing all CO2, and adding dry hops risk too much exposure to O2 with the additional headspace during the 7-10 day dry hop? Or does the layer of hops floating on top protect the beer? Or is it better to transfer to a carboy....thanks!

 

[cmoewes]

As long as you only open it enough to put the dry hops in and you don't wave a fan you shouldn't introduce any appreciable oxygen to you fermentor.

 

[ImNoExpert]

Whatever you do will expose the beer to oxygen. I'd do what's easiest and RDWHAHB.

 

[fatherdan]

I read in the Bible that Luke often dryhopped with no fear of oxygenation concerns.......

 

[GQT]

For my very first dry hopping when I was paranoid about oxygen (I still am, but pills are helping ) I put a big transparent slightly CO2-inflated plastic bag over the top of the Corny and taped to the sides of the keg. Hop sock was soaked in single malt and placed in the bag prior to filling it with CO2. Then I opened the Corny "through the bag", threw in the hops and re-sealed the keg.
Pretty much as seen on TV shows about space stations, bacterial warfare and guys with failed immune system - zero contact with the air outside the bag.

That as I now understand was a huge overkill but I still think it was cool and I regret I didn't shoot a video!

Seriously, I would even do it every time I dry hop (because it is so cool) but the paradox is that highly hopped beer is normally not meant to have a long storage/maturation period, and within its short lifespan before it's drunk out whatever oxygenation cannot do any considerable harm.

 

[day_trippr]

[...]but the paradox is that highly hopped beer is normally not meant to have a long storage/maturation period, and within its short lifespan before it's drunk out whatever oxygenation cannot do any considerable harm.

And yet, the forums are filled with "Help! My IPA Lost All Its Hop Character" threads.

After sanitation and temperature controlled fermentation, oxidation avoidance is one of the most critical aspects of brewing high quality beers that hang on to their best characters...especially for those who try to maintain a pipeline...

Cheers!

 

[hobomoto]

And yet, the forums are filled with "Help! My IPA Lost All Its Hop Character" threads.

After sanitation and temperature controlled fermentation, oxidation avoidance is one of the most critical aspects of brewing high quality beers that hang on to their best characters...especially for those who try to maintain a pipeline...

Cheers!

Yup

 

[Brewski_59]

Reading various posts on dry hopping and oxygen it seems that there is very little we can do to avoid it. There will be air trapped in the hops themselves when we dump them in. So start dry hopping while there is still some fermentation activity at the end and let the yeast metabolize what they can.

 

[RM-MN]

Currently fermenting a 90 minute iPA clone, 5 gallon batch. I have a 7 gallon fermentor and plan to plan to dry hop in the primary, will not be transferring to a secondary. Does opening the primary, releasing all CO2, and adding dry hops risk too much exposure to O2 with the additional headspace during the 7-10 day dry hop? Or does the layer of hops floating on top protect the beer? Or is it better to transfer to a carboy....thanks!

Since CO2 is about 1.5 times as dense as air, you won't be releasing much of it by opening the fermenter unless it is in a windy area. The beer itself also has a lot of CO2 dissolved in it that will help push out any oxygen you introduce with your hops as it outgasses. Don't transfer to the carboy as that will cause you to lose the CO2.:rockin:

 

[brewfun]

And yet, the forums are filled with "Help! My IPA Lost All Its Hop Character" threads.

And the culprit may turn out to be the hops, themselves. Recent research from Bamforth at UC Davis is pointing to the Manganese in the hop leaf matter as a source of flavor reduction. Yup, Manganese, not Magnesium as found in water.

The research isn't complete. But the following is from his ASBC abstract, published this year:

"Like iron and copper, manganese promotes the staling of beer, by converting ground state oxygen to reactive oxygen species. Manganese was detected in beers at levels that are likely to impact the aging of beer. Manganese originates in the grist materials but is present at even higher levels in hops. Although there is substantially more iron in those hops than manganese, the delivery into beer of these ions is much greater for manganese. Leaching of manganese into beer is much higher than in the equivalent quantity of deionized water. This study suggests that further study is warranted into the adverse impact of dry hopping on the flavor stability of beers."

 

[day_trippr]

Interesting study.

Perhaps the chemistry sets a best-case "shelf life" limit, but oxidation is a cumulative concern through all causes.
You'd have to add the deleterious effects wrt that study to all the other potential oxidation means.

So it would still pay benefits to cut those other possible causes to as close to zero as practical...

Cheers!

 

[Queequeg]

And yet, the forums are filled with "Help! My IPA Lost All Its Hop Character" threads.

After sanitation and temperature controlled fermentation, oxidation avoidance is one of the most critical aspects of brewing high quality beers that hang on to their best characters...especially for those who try to maintain a pipeline...

Cheers!

Yes I think oxidation of beer is often conflated with oxidation of hop compounds. The later takes very little oxygen and the consequences are notable in a very short time compared to oxidation of the beer.

 

[Joewalla88]

Sorry to re-open an older thread, but I don't try hop very often and was curious about this. Mostly because I accidentally sloshed my fermenter bucket after adding the dry hops. I'm pretty sure it's fine, but what do you think. Am I good?

 

[PADave]

Sorry to re-open an older thread, but I don't try hop very often and was curious about this. Mostly because I accidentally sloshed my fermenter bucket after adding the dry hops. I'm pretty sure it's fine, but what do you think. Am I good?

Most likely you are fine. Not much you can do now but go with it.

 

[oddcopter]

I'm about to dry hop an ipa. I have just thrown pellets directly into the primary before.

This time I am considering cold crashing and racking toa keg, then tossing a bag with hops in the keg, purging the oxygen, letting the temp rise back to the 60s and sit for 5 days, maybe purge once a day, pull the bag, chill and carbonate.

 

[PADave]

I'm about to dry hop an ipa. I have just thrown pellets directly into the primary before.

This time I am considering cold crashing and racking toa keg, then tossing a bag with hops in the keg, purging the oxygen, letting the temp rise back to the 60s and sit for 5 days, maybe purge once a day, pull the bag, chill and carbonate.

This is what I just did with my latest brew, which was my first keg. Previously I have always dry hopped in the primary and bottled. Did the same thing you described above, minus the cold crash, and I used a metal hop filter to put them in. I also put in 1.5 oz of corn sugar, might as well get some carb going while sitting at room temp. I plan on leaving the hops in there till the keg is kicked. So far I think the dry hops are more intense than just dry hopping in the primary.

 

[TheHairyHop]

just because CO2 is denser than air, does not mean no oxygen will be introduced. Gasses diffuse rather quickly. I would say that worrying about oxygenation is a very reasonable concern when it comes to hops. I tend to only dry hop when there are fermentables remaining in the wort. If you want to let your beer come to completion, you can always toss in a Oz or so of DME or sugar with your hops. Yeast scrub O2 like absolute fiends

 

[Taket_al_Tauro]

just because CO2 is denser than air, does not mean no oxygen will be introduced. Gasses diffuse rather quickly. I would say that worrying about oxygenation is a very reasonable concern when it comes to hops. I tend to only dry hop when there are fermentables remaining in the wort. If you want to let your beer come to completion, you can always toss in a Oz or so of DME or sugar with your hops. Yeast scrub O2 like absolute fiends

Hi, also trying to reopen this old thread... Cause a few days ago I opened a new thread asking opinions precisely on this idea of adding a small amont of sugar with the dry hops just to reactivate the yeast a little bit so that it would hopefully scavenge most of the O2 introduced.
On that thread I was discouraged to do so. Mainly because it was deemed unnecessary. Then, I and others also had concerns that the added sugar would bring some already-settled yeast back into suspension (fiy, I dry hop in primary after fermentation complete and most of yeast has settled out, I don't cold crash and I bottle condition).

What would you think about this, is it a concern or not? Intuitively I would think that the yeast that has already settled in the cake would not bother rising up again for just this tiny amount of sugar. I'm inclined to believe that only the yeast which is still in suspension would consume this sugar and hopefully scavenge most of the added O2.
Thanks!

 

[TheHairyHop]

Hi, also trying to reopen this old thread... Cause a few days ago I opened a new thread asking opinions precisely on this idea of adding a small amont of sugar with the dry hops just to reactivate the yeast a little bit so that it would hopefully scavenge most of the O2 introduced.
On that thread I was discouraged to do so. Mainly because it was deemed unnecessary. Then, I and others also had concerns that the added sugar would bring some already-settled yeast back into suspension (fiy, I dry hop in primary after fermentation complete and most of yeast has settled out, I don't cold crash and I bottle condition).

What would you think about this, is it a concern or not? Intuitively I would think that the yeast that has already settled in the cake would not bother rising up again for just this tiny amount of sugar. I'm inclined to believe that only the yeast which is still in suspension would consume this sugar and hopefully scavenge most of the added O2.
Thanks!

you're going to get some yeast back in suspension due to either growth or CO2 agitation. I don't see how that's a concern though. Just wait for it to settle back out like it did in the first place. O2 exposure is an absolute concern with dry hopping, and there is plenty of evidence out there to warrant taking mitigation measures. Even packaging techniques have been shown to make a difference. As much as I don't approach of Brulosophy's "statistics", the hard evidence of pictures illustrating oxidation are hard to ignore. They didn't even purposefully expose one beer to O2. They just actively tried to limit exposure on one and did the "normal" routine on the other

 

[Taket_al_Tauro]

Ok thanks! So I'll try this trick and let's see. The concern was only because I'm using some rather powdery yeast that will take its time to settle (wy 1450). Anyway this time I'll also try some small experiment at bottling: purging bottles and headspaces with Private Preserve (wine preserving gas mixture )... Poor man approach in absence of a kegging setup. I'm really having the feeling right now that oxidation is the next thing to focus on in order to further improve my hoppy beers .

 

[Sadu]

Adding a bit of sugar at the same time as the dry hop is a good idea IMO. It restarts fermentation again, that is finished within a day then you cold crash and everything drops out again.
I did this on my most recent batch, I'm hoping to get the local brewery to run a bottle through their DO meter and see how things are looking.

 

[TheHairyHop]

Ok thanks! So I'll try this trick and let's see. The concern was only because I'm using some rather powdery yeast that will take its time to settle (wy 1450). Anyway this time I'll also try some small experiment at bottling: purging bottles and headspaces with Private Preserve (wine preserving gas mixture )... Poor man approach in absence of a kegging setup. I'm really having the feeling right now that oxidation is the next thing to focus on in order to further improve my hoppy beers .

what I started doing was adding the sugar solution, waiting an hour or so for fermentation to start back up, and then adding hops. Just so that the delay is sucking up the oxygen is minimized. As for bottling, you could go with something like krausening if you really want to be particular. The active fermentation could do some leg work

 

[Taket_al_Tauro]

Pardon my ignorance, what do you mean with krausening with respect to bottling?

From what I read so far I got the feeling that the air remaining in the headspace is the biggest culprit for oxidation of bottled hoppy beers.
So I'll try doing some variants, like a few non purged bottles, a few with only the headspace purged, and a few completely purged (bottle prior to filling and headspace after filling). Then do some side to side compares at different time points and see... It's nothing new under the Sun for sure, but really looking forward to see if that can bring some benefits for my hoppy beers...

 

[cmoewes]

Pardon my ignorance, what do you mean with krausening with respect to bottling?

Krausening is using unfermented wort (either held over after the boil or from the next batch of beer) and using that to provide the sugar for bottle conditioning. It's action would be similar to using regular priming sugar but it's a old german method for following the purity laws.

 

[ESBrewer]

In fact, kräusening is adding wort + fresh yeast to the bottles (bottling bucket, beer), whereas adding the wort alone is called speise. Kräusening tends to cause more rapid secondary fermentation in the bottles because there are more viable yeast cells. This means oxygen is probably consumed in a more rapid pace, before it reacts with beer. Additional yeast may sometimes help with removal of diacetyl etc. and it may also lead to higher amount of sediment at the bottom of the bottle, depending on how much yeast is added, of course. Small amount of addtional yeast will suffice. It is also possible to add some fresh yeast from a starter culture together with priming sugar to obtain some of the benefits of kräusening without the need to have the wort at hand (or without the need to calculate the correct amount of wort...).

 

[TheHairyHop]

ah yea, forgot to respond. Adding just wort is speisse. Krausening involves adding wort that is actively fermenting, i.e., it probably came from actual krausen on another batch in a fermenter

 

[Taket_al_Tauro]

Thanks guys for the detailed responses!
OK, I knew about the Speise-Approach since I've been reading quite a bit on the German homebrewing forum too. But I did not hear about this Krausening approach yet, or maybe just in relation to adding some fresh yeast for bottle-conditioning beers with a very high OG.

It is also possible to add some fresh yeast from a starter culture together with priming sugar to obtain some of the benefits of kräusening without the need to have the wort at hand (or without the need to calculate the correct amount of wort...).

Did you try it already yourself in a hoppy beer, and saw benefits with respect to minimizing oxidation?
Guess it would make another interesting experiment: conditioning a part of the bottles with extra fresh yeast and a part as normal.

For me it would mean the extra work of building up a fresh starter just for this purpose, since I am not brewing that often, unfortunately...
So I may consider doing this only if it makes a noticeable difference.
And in any case I'll stick to priming sugar. It's way more straightforward than Speise and from what I heard, nailing down the correct level of carbonation can be tricky with Speise... besides, I am not a Reinheitsgebot-believer, even though I lived for some years in Germany and even some breweries in my own country (Switzerland) are still affected by this myth ;-).

 

[ESBrewer]

^In terms of oxygen, I think think the whole kräusening/adding yeast thing is an additional method that you can try if you really need to fine tune things. It is more important to consider the fermenter (head space and how & when you open it to let oxygen in), beer transferring practices and the head space in the bottle. I have only tried it once and it seems to speed up the carbonation as expected, but I have not used it to control oxygen. Partly because I haven't noticed major problems arising from oxygen in my beer, yet. But that may be because there have been other more noticeable 'faults' in my brews and those were no IPAs. So if you are just starting out or you are limited in yeast, you should probably focus on the other aspects in first place. As TheHairyHop said when he mentioned this technique - 'if you want to be particular'.

 

[Taket_al_Tauro]

Hi, yeah for me this Kräusening thing definitely also falls in that same category: "if you really want to be particular". I guess I'll not try this method anytime soon, I also believe there are other things which can play a much bigger role.
And by the way, I just finished bottling this IPA and the beer is really cloudy...probably as a consequence of the small amount of sugar added together with the dry hops (didn't cold crash, because I currently don't have the possibility to do so). So I guess I've got more than enough viable yeast in there anyway ;-).

Actually, I've been happy with my latest IPA attempts, yet I feel there is still room for improvement, particularly with respect to that punchy, in-your-face dry hop aroma. I've not been able to achieve the same level of intensity as some of the best fresh commercial examples I tried. That's why I started focusing my efforts on cold-side oxidation lately.

I'm really looking forward to see if purging bottles/headspaces is going to bring some benefits or not...

 

[MotoGP1000]

Looking at an old thread here but I was wondering the same after batches and batches I've brewed already.
I just waited a little past high krausen on this current batch. My beer isn't quite fully done fermenting but the krausen has subsided. What I have noticed is that my air lock is getting pushed up a little after dry hop and reapplying the lid meaning there is still some reaction happening in the beer keeping a layer of CO2 in there and probably moving whatever introduced O2 from opening the lid out.

Ultimately I'll close transfer to my keg. Ps for those wondering. I have noticed a big difference in the quality of my beer since moving from bottles to kegs. Very happy to be kegging now .