Oxydation and the fermonster

[ashopis]

Hey there,

I've been having an oxydation problem lately (I think). Most of my hazy hoppy NEIPA's are coming out dark and not very hoppy despite 6ozn of hops in whirlpool and another 6 in dry hop. This problem semmed to start when I swithced from my old bucket fermenter to a fermonster.

Has anyone had an issue like this with a fermonster? Is it possible it's not sealing correctly? Any suggestions?

Thanks you

 

[Bobby_M]

You can check the seal by inserting a solid stopper, spray around the lid with soapy water and squeeze the fermenter to look for bubbles. I use Fermonsters a lot and found that bucket lids are way more leaky on average. Make sure your oring is evenly seated and it doesn't hurt to put a light coating of vaseline on the oring to help the lid slide into place.

You're brewing one of the most difficult styles in terms of post ferment handling. If you're using racking canes and open top bottling buckets or kegging without doing a completely oxygen free transfer process, that's more likely the issue.

 

[mirthfuldragon]

I've done half a dozen using my Fermonsters, without issue. I use spigoted ones, with mylar balloons for CO2 capture and to prevent suck-back when cold-crashing, and kegging into a filled-and-purged keg.
The lid o-rings are a pain to get right - best to watch the YouTube video on how to install them.

 

[jjw5015]

I've used buckets and Fermonsters and don't notice a difference. Fermentation vessel is rarely the cause of oxidation. It's whatever you do once it leaves the vessel that causes this.

 

[Rob2010SS]

If you look at some of the reviews of the Fermonsters with spigots, I've seen a few where people complained that they caused their beer to oxidize from poor sealing. How much of that is legit - no idea. The fact that people have had issues makes me question them.

However, I think @Bobby_M has a point. How do you handle these once fermentation is finished?

 

[odie]

I have 2 Fermonsters and 2 buckets I use regularly...I have no issues...and I don't seal them either tight either, just snug...lets the excess co2 pressure out and keeps O2 from sneaking in...tighten lids before cold crash and purge keg several times immediately after filling...

An undisturbed fermenter is probably not a source of oxidation

 

[Robert65]

I have 2 Fermonsters and 2 buckets I use regularly...I have no issues...and I don't seal them either tight either, just snug...lets the excess co2 pressure out and keeps O2 from sneaking in...tighten lids before cold crash and purge keg several times immediately after filling...

An undisturbed fermenter is probably not a source of oxidation

If the fermenter is not positively sealed, and constructed of non- gas permeable materials, oxygen will indeed enter by diffusion, no matter what the absolute pressure inside is. It's partial pressure of each gas on either side that matters. That's the law. Several of them in play, really. And if by "purge several times" you mean pressurizing and burping the PRV, that does virtually nothing to eliminate oxygen in the keg, by operation of the same gas laws.

 

[Rob2010SS]

And if by "purge several times" you mean pressurizing and burping the PRV, that does virtually nothing to eliminate oxygen in the keg, by operation of the same gas laws.

Ehhhh, I'm going to disagree with you there.

This is straight from the Low Oxygen Brewing website, link here.

Granted, he is talking about doing this before racking beer over to the keg. But once beer is in the keg, wouldn't the same principle apply to the headspace in the keg? You're going to reduce the PPM of O2 remaining in the headspace by purging so many times?

 

[Robert65]

Ehhhh, I'm going to disagree with you there.

View attachment 657846

This is straight from the Low Oxygen Brewing website, link here.

Granted, he is talking about doing this before racking beer over to the keg. But once beer is in the keg, wouldn't the same principle apply to the headspace in the keg? You're going to reduce the PPM of O2 remaining in the headspace by purging so many times?

The only practical method of purging a keg is to fill the keg with liquid and push it out with CO2, as explained on the LOB site. As you see from the information presented there, to sufficiently reduce O2 by pressurize/ release cycles, you need at least 16 full cycles at 30 psig, an enormous waste of time and gas. If you have already liquid purged the keg before transfer, and are careful in executing the transfer, a few burps of the PRV will at least reassure you. But the keg must be fully liquid purged before the transfer, or the oxidation damage will already be done in the transfer, and nothing will reverse it. Furthermore, no transfer can practically be made oxygen free, so beer should never be transferred after fermentation is complete. In order to have a chance of really minimizing oxidation, it should be transferred with sufficient remaining fermentable extract and spunded in the keg, so that active yeast will scavenge the inevitable oxygen picked up in the process. This will make a tremendous difference in highly vulnerable styles like the NEIPA under discussion in the OP.

 

[ListerH]

The only practical method of purging a keg is to fill the keg with liquid and push it out with CO2,

+1 on this... the only way I have found to effectively minimize O2 in my keg headspace is to liquid purge and then rack to the keg through the liquid "out" post with the PRV open to allow release of gas. I ferment in a corny keg so connecting the 2 out posts and using a CO2 tank to push through is the method I have had the most success with.

Slightly off topic from the OP

 

[Rob2010SS]

The only practical method of purging a keg is to fill the keg with liquid and push it out with CO2, as explained on the LOB site. As you see from the information presented there, to sufficiently reduce O2 by pressurize/ release cycles, you need at least 16 full cycles at 30 psig, an enormous waste of time and gas. If you have already liquid purged the keg before transfer, and are careful in executing the transfer, a few burps of the PRV will at least reassure you. But the keg must be fully liquid purged before the transfer, or the oxidation damage will already be done in the transfer, and nothing will reverse it. Furthermore, no transfer can practically be made oxygen free, so beer should never be transferred after fermentation is complete. In order to have a chance of really minimizing oxidation, it should be transferred with sufficient remaining fermentable extract and spunded in the keg, so that active yeast will scavenge the inevitable oxygen picked up in the process. This will make a tremendous difference in highly vulnerable styles like the NEIPA under discussion in the OP.

Not disagreeing with you on any of that. I've been getting into the Low Oxygen stuff myself, I'm on board with it.

I was simply stating that I didn't think your other statement was correct (and I could still very well be wrong), that purging the keg via the PRV "did nothing to reduce oxygen". That was all I was getting at.

Sorry OP, didn't mean to hijack your thread.

 

[doug293cz]

If the fermenter is not positively sealed, and constructed of non- gas permeable materials, oxygen will indeed enter by diffusion, no matter what the absolute pressure inside is. It's partial pressure of each gas on either side that matters. That's the law. Several of them in play, really. And if by "purge several times" you mean pressurizing and burping the PRV, that does virtually nothing to eliminate oxygen in the keg, by operation of the same gas laws.

Pressurizing followed by venting definitely does reduce O2 concentration in the headspace. Read my link below.

Ehhhh, I'm going to disagree with you there.

View attachment 657846

This is straight from the Low Oxygen Brewing website, link here.

Granted, he is talking about doing this before racking beer over to the keg. But once beer is in the keg, wouldn't the same principle apply to the headspace in the keg? You're going to reduce the PPM of O2 remaining in the headspace by purging so many times?

Most of that Low Oxygen Brewing article is straight from a post written by me on HomeBrewTalk. Read the two articles side by side. There is a lot of cut and paste in the LOB article. I created the chart and table on headspace purging, and it was originally published here on HomeBrewTalk.

Brew on

 

[RPh_Guy]

Back on topic,

Has anyone had an issue like this with a fermonster? Is it possible it's not sealing correctly?

Just want to +1 what everyone else said.
If you properly seat the o-ring, it forms an air-tight seal and also holds pressure. I have about 8-10 Fermonsters (I love them) and I make low-oxygen beer.

The reviewers experiencing leaks must not have seated the o-ring properly. I agree it can be a pain the first time, but then it stays in place.
If it's a problem, try putting the o-ring in ice water for several seconds before attempting to seat it.

 

[doug293cz]

The only practical method of purging a keg is to fill the keg with liquid and push it out with CO2, as explained on the LOB site. As you see from the information presented there, to sufficiently reduce O2 by pressurize/ release cycles, you need at least 16 full cycles at 30 psig, an enormous waste of time and gas. If you have already liquid purged the keg before transfer, and are careful in executing the transfer, a few burps of the PRV will at least reassure you. But the keg must be fully liquid purged before the transfer, or the oxidation damage will already be done in the transfer, and nothing will reverse it. Furthermore, no transfer can practically be made oxygen free, so beer should never be transferred after fermentation is complete. In order to have a chance of really minimizing oxidation, it should be transferred with sufficient remaining fermentable extract and spunded in the keg, so that active yeast will scavenge the inevitable oxygen picked up in the process. This will make a tremendous difference in highly vulnerable styles like the NEIPA under discussion in the OP.

I agree that it would be very wasteful to purge an empty keg using the pressurize and vent method, but it will work. As you say, it is much more efficient to liquid purge the keg prior to filling.

Brew on

 

[Dgallo]

A lot of the issues you may be getting from using your fermonster with a spigot is due to taking samples. If you’re pulling tasting and hydro samples often, every time you take volume, it is replaced with o2 being sucked through the airlock.

Dryhoping practices can also add to the oxidation.

But as stated by many here, I’d say as high as 85% of oxidation issues happen during and after racking from the FV. Also If you’re not properly purging your kegs completely, or not perfect on bottling techniques, that’s where most oxidation takes place

 

[Dgallo]

You can turn your fermonster into a closed system with a solid lid, 7/16 drill bit, and fitting the lid with a liquid and co2 keg post and diptube or CBS. That’s what I have done

 

[mirthfuldragon]

You can turn your fermonster into a closed system with a solid lid, 7/16 drill bit, and fitting the lid with a liquid and co2 keg post and diptube or CBS. That’s what I have done

How/where did you get the female threaded connectors for the posts?

 

[Dgallo]

How/where did you get the female threaded connectors for the posts?

Lhbs but I know many who have done the same as me actually just purchased the pressure kit for the fermontisorus and just use its hardware for the fermonster
https://www.amazon.com/Fermentasaurus-FE101-Pressure-Kit/dp/B074DB72BB/ref=mp_s_a_1_3?adgrpid=55035552374&gclid=EAIaIQobChMIuL6V96bF5gIVEj0MCh0WFgILEAAYASAAEgLJefD_BwE&hvadid=274897751239&hvdev=m&hvlocphy=9004628&hvnetw=g&hvpos=1t1&hvqmt=e&hvrand=17973906515034944842&hvtargid=aud-840076997981:kwd-392921019560&hydadcr=12157_9565258&keywords=fermentasaurus+pressure+kit&qid=1576881944&sr=8-3

 

[WBB]

A lot of the issues you may be getting from using your fermonster with a spigot is due to taking samples. If you’re pulling tasting and hydro samples often, every time you take volume, it is replaced with o2 being sucked through the airlock.

I don’t have a fermonster but have curbed that by using a blowoff tube in a jar of star San all the time now. When I pull a sample for gravity testing, you can see the liquid being pulled up the tube, but if you do it slow enough and gather what you need to test with, the pressure is not enough to draw in the star San. Then continued fermentation pushes the liquid back down and it bubbles again.

 

[Dgallo]

I don’t have a fermonster but have curbed that by using a blowoff tube in a jar of star San all the time now. When I pull a sample for gravity testing, you can see the liquid being pulled up the tube, but if you do it slow enough and gather what you need to test with, the pressure is not enough to draw in the star San. Then continued fermentation pushes the liquid back down and it bubbles again.

That’s certainly a method that will help. Many using the 7.25 g fermonster have enough headspace for fermentation and choose not to use a blow off(they should though since it’s good practice). That said after ferms over, those not careful can draw in

 

[jjw5015]

You can turn your fermonster into a closed system with a solid lid, 7/16 drill bit, and fitting the lid with a liquid and co2 keg post and diptube or CBS. That’s what I have done View attachment 657858

Does it work with just a gas post and using the bottom spigot to transfer?

 

[Dgallo]

Does it work with just a gas post and using the bottom spigot to transfer?

Yeah it will work but keep in mind that you run the risk of transfer more yeast/hop material to your keg that way.

Side note about the co2 post, during fermentation you can connect the FV to a keg filled with sterilizer solution through the kegs gas post and then run a line from the kegs liquid post to a bucket and utilize the co2 produced during ferm to completely purge the keg. What’s nice is this co2 maintains some of the aroma compounds from the hops/yeast esters that are typically just blown away. You will also be able to cold crash and dryhop under pressure

 

[ashopis]

Thanks for all the help on this. I’m noticing the oxydatikn, however, as I transfer to keg via racking vane. I take a sample for fg via the cane and th beer is way darker than it should be and has scant hippiness despite. 6 oz galaxy in whirlpool and another 6 in dry hop. So somehow O2 is getting in during fermentation.

I dry hopped 48 hours after pitch to allow yeast to munch any O2 that got in during dry hopping.

Weirdly, my Imperial Juice had stopped bubbling at the 48 hr. Mark.

 

[Dgallo]

Thanks for all the help on this. I’m noticing the oxydatikn, however, as I transfer to keg via racking vane. I take a sample for fg via the cane and th beer is way darker than it should be and has scant hippiness despite. 6 oz galaxy in whirlpool and another 6 in dry hop. So somehow O2 is getting in during fermentation.

I dry hopped 48 hours after pitch to allow yeast to munch any O2 that got in during dry hopping.

Weirdly, my Imperial Juice had stopped bubbling at the 48 hr. Mark.

Are you making a solid starter, though fermentation uses the dissolved oxygen, if you lag time is to great it can cause oxidation.

Also if you’re dryhoping isn’t smooth and precise you can pick up at that time. Is there temp control or does the ferment change temps from day and night, that can cause a draw of air into your fermenter.

Biggest question is if you are cold crash before racking?

 

[ashopis]

Dgallo,

I don't use a starter, I used a bag of Imperial Juice, which claims 200 billion cells. Anecdotally, the lag didn't seem particularly long.

Dry hopping could be an issue. I try pretty hard to keep it quick and smooth, but who knows! I added two mesh sacks with 3 oz of Galaxy each.

I don't cold crash.

 

[Dgallo]

Dgallo,

I don't use a starter, I used a bag of Imperial Juice, which claims 200 billion cells. Anecdotally, the lag didn't seem particularly long.

Dry hopping could be an issue. I try pretty hard to keep it quick and smooth, but who knows! I added two mesh sacks with 3 oz of Galaxy each.

I don't cold crash.

In general, I would start looking into pitch rate calculators. Viability of yeast drops rather quickly from the manufacture date. I use imperial yeast my self a still typically need a 1l starter.

The mesh bag is most likely your issue. The bag traps air inside with the hops and the material it’s made out of is porous and air can get trapped within the fibers. I make primarily NEIPAs and always dryhop loose. Even up to about 8-9oz split between two dh additions. I’ve found this to be the best way to minimize o2 pick up during dhing(I also close transfer to completely purged kegs). My aroma is always full and color is bright. This is a beer that was in the keg for 6 weeks already