No oxygen dry hopping

[mattdee1]

I can drink a simple beer (blonde ale, etc.) out of a can if I'm camping, but yeah, drinking most kinds of good beer right from its container is a travesty, IMO.

Especially on IPAs and aroma-heavy beers. Some people really seem to underestimate the role your nose plays in "tasting" beer. To any doubters, pour your favorite IPA into a glass, and take a nice slow sip. Tastes great, yeah? Now, with your free hand, plug your nose completely and take another sip from the glass.

 

[mongoose33]

Mongoose shouldn’t the purged keg in the pic above have a co2 line running to a bucket of starsan to create an airlock?

Should it? I suppose when the flow of CO2 slows down it would make sense to do that. No reason why a gas QD couldn't have a tube attached and have it terminate in a blowoff jar.

 

[day_trippr]

Mongoose shouldn’t the purged keg in the pic above have a co2 line running to a bucket of starsan to create an airlock?

That's what I do, both when filling with sanitizer [inverted keg], and when filling with beer. Just feel better about keeping O2 that much further from my precious neipas than an open PRV or a bare QD on the gas post

I don't use Star San in the bucket, just plain water. It's not going to go backwards...

Cheers!

[edit] As it happens I had to keg my latest neipa batch today, so...

First keg on the scale...

...and filled.

2nd keg...

...all done.

 

[akpingel]

Ok- why are you weighing your beer?

 

[day_trippr]

So I know how much beer is in the keg.
I run a metered tap list and when a keg goes on-line I want a solid starting volume...

Cheers!

 

[Jag75]

So I know how much beer is in the keg.
I run a metered tap list and when a keg goes on-line I want a solid starting volume...

View attachment 669715

Cheers!

Is that on a tv ? I like that looks cool

 

[day_trippr]

I can view my Raspberry Pints tap list literally anywhere with an internet connection - the above was a screen grab from my office workstation - but its primary function is to drive the display atop my keezer tower...

Cheers!

 

[Cape Brewing]

Nerd

 

[day_trippr]

Yup.

 

[SEndorf]

I don't use Star San in the bucket, just plain water. It's not going to go backwards...

I'm guilty of always sticking the line in a bucket of star-san. Not sure why. Old habit.
From now on, I'll leave the star-san alone and fill with water.

 

[Robert65]

When filling a keg, my method to ensure no O2 ingress is to put a picnic tap on the gas post and periodically bleed pressure to maintain flow. Like the purge valve on a CP bottling rig. This also ensures that things don't get away from me if I step away.

 

[CodeSection]

I can view my Raspberry Pints tap list literally anywhere with an internet connection - the above was a screen grab from my office workstation - but its primary function is to drive the display atop my keezer tower...


View attachment 669729

Cheers!

Impressive setup!

 

[ttuato]

I will contribute to the thread - I used some of the knowledge here and crafted my own version/process for lodo dryhopping spike flex+.

Since I hop heavy I wanted the chamber large enough to hold at least 16ozs of pellets at once - roughly the equivalent of a quart mason jar. I tested reducers to spools to the 1.5" opening on top of flex. Not only did it require long reducers/spools but the 1.5" butterfly did not dump the hops very easily. So I shifted to the 4" cap and used 4" to 3" concentric reducer and 3" butterfly valve. This valve dumped effortlessly and only needed about 10" spool. This allowed me to use the 3" hop filter from brewhardware.com That I already owned. I removed the inner hard filter so that it just a "tube" - one end is 3", the other is 1.5". I added a 1.5" cap with ball lock gas connect and attached a hose to the bottom that is the length of the tube (more later on later)

• I purged a keg using fermentation gas for a couple of days, I removed the blowoff and harvested some gas into the keg while spunding the beer to 15psi. The PRV in the flex limited the pressure that could build in the attached keg as well, which avoided any risk of over pressurizing the dryhopper later in the process.
• When time to dryhop, I pulled the spike from from the fridge
• With the gas line inside the tube I filled the hops (tube will hold ~18-20oz). I used the ferm gas from keg to purge gas cap first so it will push O2 out of gas line. Then I used my nitro purge wand to purge from bottom which pushed up through the hops. Then I held the cap down and slowly opened the butterfly valve so that the spunded gas would purge again from the bottom up through the hops - repeated this twice. I then sealed and used the last of the keg ferm gas to pressurize the dryhopper, then opened the butterfly fully to dump hops and closed back.
  
• Entire process took about five minutes
• 
  
  
  
  
  
  
  
  
• 

 

[mcl]

Here is a pic of my setup using the Brewers Hardware conical. I used the reducer as I had a 3" port available and it also shouldn't clump and jam. Also I have to ability to put one of my PRV valves on top if I want. I don't have it configured that way at the moment.

 

[bracconiere]

who knows what actually happens to it all

https://www.npr.org/sections/goatsa...lastic-trash-go-now-that-china-doesnt-want-it

 

[jturman35]

I will contribute to the thread - I used some of the knowledge here and crafted my own version/process for lodo dryhopping spike flex+.

Since I hop heavy I wanted the chamber large enough to hold at least 16ozs of pellets at once - roughly the equivalent of a quart mason jar. I tested reducers to spools to the 1.5" opening on top of flex. Not only did it require long reducers/spools but the 1.5" butterfly did not dump the hops very easily. So I shifted to the 4" cap and used 4" to 3" concentric reducer and 3" butterfly valve. This valve dumped effortlessly and only needed about 10" spool. This allowed me to use the 3" hop filter from brewhardware.com That I already owned. I removed the inner hard filter so that it just a "tube" - one end is 3", the other is 1.5". I added a 1.5" cap with ball lock gas connect and attached a hose to the bottom that is the length of the tube (more later on later)

• I purged a keg using fermentation gas for a couple of days, I removed the blowoff and harvested some gas into the keg while spunding the beer to 15psi. The PRV in the flex limited the pressure that could build in the attached keg as well, which avoided any risk of over pressurizing the dryhopper later in the process.
• When time to dryhop, I pulled the spike from from the fridge
• With the gas line inside the tube I filled the hops (tube will hold ~18-20oz). I used the ferm gas from keg to purge gas cap first so it will push O2 out of gas line. Then I used my nitro purge wand to purge from bottom which pushed up through the hops. Then I held the cap down and slowly opened the butterfly valve so that the spunded gas would purge again from the bottom up through the hops - repeated this twice. I then sealed and used the last of the keg ferm gas to pressurize the dryhopper, then opened the butterfly fully to dump hops and closed back.
  
• Entire process took about five minutes
• 
  
  
  
  
  
  
  
  
• 

Wish the pictures were viewable.

 

[ShaLaH]

OK, time to report! Finally had a chance to try out the butterfly valve/sight glass/pressure manifold thing to introduce dry hopping hops, and I'm pleased to report that....it worked!

Here's a short video showing how it went down:

I tried dry hopping using this technique today. Here's what happened:

I put the butterfly valve on the 1.5" port, then the sight glass filled with hops on that, then the spike manifold on top of that (just how you have it). I cracked the butterfly valve open slightly, then hooked up CO2 to the manifold and added a 3-4 psi. Waited a couple minutes for sight glass to fill with CO2. Then, I opened the valve, working it back and forth but the hops wouldn't drop. I had to take everything apart and just dump the damn hops in. Somehow the hops got pushed up into the manifold and were compacted. What did I do wrong?

I'm assuming I didn't release the pressure before dropping the hops right?

 

[kevink]

I tried dry hopping using this technique today. Here's what happened:

I put the butterfly valve on the 1.5" port, then the sight glass filled with hops on that, then the spike manifold on top of that (just how you have it). I cracked the butterfly valve open slightly, then hooked up CO2 to the manifold and added a 3-4 psi. Waited a couple minutes for sight glass to fill with CO2. Then, I opened the valve, working it back and forth but the hops wouldn't drop. I had to take everything apart and just dump the damn hops in. Somehow the hops got pushed up into the manifold and were compacted. What did I do wrong?

I'm assuming I didn't release the pressure before dropping the hops right?

I use a 2" valve and they dump right in. Did you try tapping on the valve with a rubber mallet or something like that?

 

[ShaLaH]

I use a 2" valve and they dump right in. Did you try tapping on the valve with a rubber mallet or something like that?

yup, definitely banged on it. I have the spike cf5, so I only have access to a 1.5" port on the lid.

 

[kevink]

yup, definitely banged on it. I have the spike cf5, so I only have access to a 1.5" port on the lid.

Damn. Did you make sure that there were no two pellets stuck together? That can cause problems. They all have to be completely un-stuck from each other.

 

[ShaLaH]

Damn. Did you make sure that there were no two pellets stuck together? That can cause problems. They all have to be completely un-stuck from each other.

I didn't. I think next time I'll grind the hops up and then add to the sight glass.

 

[mongoose33]

Here's what I know about how this works.

First, you need to not overfill with hops. Otherwise, when you open the valve you're going to compress some of those hops upward, which will create bridging.

That's the fundamental issue--bridging. A 2" valve would be better, as @kevink has above but if you have the 1.5" valve (which you do), you have to be careful with that.

I had CO2 hooked up to mine with the idea that I might need to blast them down into the fermenter. That's never worked particularly well but I thought a shot of CO2 at, say, 20 or 25 psi might do it.

I also found this: When I did this in my garage in the winter, where the garage was 40-50 degrees ambient, and I had beer fermenting at, say, 65 degrees, I'd get condensation on the inside of the sight glass. This made the hops sticky to some extent. So that has to be addressed too. During warmer periods in the garage it isn't an issue.

I'm guessing you maybe had too many hops jammed in there.

*****

The idea behind this in part was to add the hops a day or so ahead of dropping them so that the CO2 being produced by the yeast would purge the hops in the sight glass, allowing the excess to flow out the manifold. That would purge them completely, then I'd drop them.

Just pouring in the hops, adding some CO2, and dropping them doesn't purge of oxygen.

 

[ShaLaH]

Here's what I know about how this works.

First, you need to not overfill with hops. Otherwise, when you open the valve you're going to compress some of those hops upward, which will create bridging.

That's the fundamental issue--bridging. A 2" valve would be better, as @kevink has above but if you have the 1.5" valve (which you do), you have to be careful with that.

I had CO2 hooked up to mine with the idea that I might need to blast them down into the fermenter. That's never worked particularly well but I thought a shot of CO2 at, say, 20 or 25 psi might do it.

I also found this: When I did this in my garage in the winter, where the garage was 40-50 degrees ambient, and I had beer fermenting at, say, 65 degrees, I'd get condensation on the inside of the sight glass. This made the hops sticky to some extent. So that has to be addressed too. During warmer periods in the garage it isn't an issue.

I'm guessing you maybe had too many hops jammed in there.

*****

The idea behind this in part was to add the hops a day or so ahead of dropping them so that the CO2 being produced by the yeast would purge the hops in the sight glass, allowing the excess to flow out the manifold. That would purge them completely, then I'd drop them.

Just pouring in the hops, adding some CO2, and dropping them doesn't purge of oxygen.

Thank you sir. That is exactly what happened, I crammed the 1.5" sight glass full of hops and they did indeed compress up into the manifold.
I also missed the part where you let the hops sit for a day prior to dropping them. Knowledge for next time, thanks for the info.

 

[ttuato]

@jturman35 @mkblackmart @murphyslaw @duelerx

here are the images. Again smaller sized so hopefully will come through. My Process/setup is similar to @mcl posted after me. Here is what I have learned / changed after 9 batches - tgis only works if you spund.

• Dont need the balllock pressure thing at top, just use a flat TC plate to cap the top
• Use wand to purge device from bottom after mounting dryhop tube
• Add hops, insert wand again and purge hops, quickly put on TC cap.
• Add TC clamp to cap but do not tighten yet
• Barely & slowly crack the dump valve just enough so that the PURE CO2 from FV will enter the DH chamber from bottom for a, resulting in a third purge.
• While the pure CO2 is exiting the dryhopper, tighte the TC clamp at the top, sealing the dryhopper. Wait a few seconds for the pressure to normalize, then dump
• RESULTS - I have seen a definite improvement in the shelf life using this method, aroma stays tight, nocardboard flavors, no color change, etc.
• BUT - big BUT - I have noticed that floculation is playing a bigger role in the later part. Normally I finish my hazies in 6-8 or less. I purposefully left one in the keezer for 12 weeks with about 2gal. No signa of oxidation still but the flavor & mouthfeel had declined (I use floating diptubes). As it got closer to the bottom where all of the goodness had flocced out, thw flavor moutfeel came back...
• 
  
  
  
  

 

[Vale71]

The idea behind this in part was to add the hops a day or so ahead of dropping them so that the CO2 being produced by the yeast would purge the hops in the sight glass, allowing the excess to flow out the manifold. That would purge them completely, then I'd drop them.

Just pouring in the hops, adding some CO2, and dropping them doesn't purge of oxygen.

Your technique doesn't purge the chamber completely either. The reason being, oxygen is a gas and it will diffuse in all directions, including into the FV's headspace, and not just flow out of the manifold. The result will be that you will have to wait for fermentation to purge all the residual oxygen from the headspace and the dry hopping chamber s well and this will most likely take longer than one day. If one want to be sure that residual oxygen levels are negligible one ought to actively purge the chamber before opening the valve, which would also allow dry hopping at a later time when active fermentation is done.

 

[mongoose33]

Your technique doesn't purge the chamber completely either. The reason being, oxygen is a gas and it will diffuse in all directions, including into the FV's headspace, and not just flow out of the manifold. The result will be that you will have to wait for fermentation to purge all the residual oxygen from the headspace and the dry hopping chamber s well and this will most likely take longer than one day. If one want to be sure that residual oxygen levels are negligible one ought to actively purge the chamber before opening the valve, which would also allow dry hopping at a later time when active fermentation is done.

I don't do it the first day. I wait until the 3rd day, generally, before any of his happens. Meanwhile the oxygen in the headspace is either being consumed by the yeast, or being expelled by the CO2 released. Given the volume of CO2 being produced, by the third day the headspace should be clear of O2, and then I begin the process of hops in the sight glass. I'll close the butterfly valve and let the fermenter build up a bit of CO2 pressure, add the hops, top off with the manifold, and then crack the valve a bit to allow CO2 to escape through the hops.

Is it producing a perfectly oxygen-free environment? I think it's pretty good, darned good in fact, but perfect? Nah.

But it's one heck of a lot better than the old way of doing it, i.e., open up the fermenter, dump in the hops, allow a lot of air and O2 to mix in, and close back up.

********​

During fermentation about 1 volume of CO2 is produced for every 2 points of gravity drop (this from the low-oxy stuff). It takes about 25 purges of a vessel with pure CO2 to get down to a virtually O2-free environment. So if it dropped in gravity from, say, 1.060 to 1.010, that's 50 points; divided by 2 is 25 volumes. So a 5-gallon batch produces about 125 gallons of CO2.

Roughly. Lower starting gravity, or higher finishing gravity reduces that somewhat.

So when that expelled CO2 goes through the much smaller volume of the sight glass and associated connections, it's purging that space pretty quickly. I haven't done the math, but even one volume of CO2 produced (5 gallons) is....well, time out while I do a little math:

Assume a 12-inch cylinder of sight glass etc. times 1.5" of diameter....lessee....pi-r-squared is the area of the circle....3.14 x .75 x .75 is ...about 1.77 square inches. Times 12" of height is 21.24 cubic inches of volume in the sight glass and associated stuff. (overestimating by a bit, but that's ok, it's the right side on which to make that error, more conservative).

There are 231 cubic inches in one gallon; in five gallons there are 1155 cubic inches. Divide that by the 21.24 cubic inches of the sight glass, and 1-volume of CO2 from fermentation will be equivalent to....1255 / 21.24 = 59.xx. Or 59 purges. You can check the math, but I think it's right.

So if one doesn't allow air to go into the top of the fermenter while doing this, one should be able to purge the sight glass, and the hops inside, in just the few hours it takes for fermentation to drop gravity by about 2 points.

That's why I do it late--to purge the headspace of the fermenter and then allow enough remaining fermentation to purge the sight glass and hops.

******​

Perfect? No. I'm sure there's O2 inside hop pellets, though not much. Probably can't get rid of that in purging, but its volume compared even to the sight glass is miniscule. But when I dump in the hop pellets and they melt in the beer, that O2 should be consumed by the yeast.

********​

It's better to use the CO2 produced by fermentation, if possible, because it's pure. CO2 from a tank, unless one paid for a very high level of purity, is about 99.5 percent CO2; the rest air. In that air is 21 percent oxygen. So 21 percent of the remaining .5 percent is about .1 percent, so in one's CO2 is about .1 percent oxygen. Just trying to eliminate all the O2 I can.

 

[Vale71]

It's better to use the CO2 produced by fermentation, if possible, because it's pure. CO2 from a tank, unless one paid for a very high level of purity, is about 99.5 percent CO2; the rest air. In that air is 21 percent oxygen. So 21 percent of the remaining .5 percent is about .1 percent, so in one's CO2 is about .1 percent oxygen. Just trying to eliminate all the O2 I can.

That is wrong and I've already pointed it out to you several times. Just download the specs for food grade CO2 from the major suppliers and you'll see that they guarantee at most 50ppm of residual O2, at best as little as 20ppm. That's a far cry from 0.5% or 5000ppm. If 50 ppm is still too much for you could purge the hopper with a high vacuum pump and skip the last pressurization step. If you drop residual pressure down to a few millibar and then crack open the valve letting headspace gas fill the cylinder you'd hardly have introduced any residual O2 from your bottled CO2.

As for keeping the O2 out of the headspace with your method the problem is that fermentation only creates a very slow flow of CO2, way too slow to mechanically purge the cylinder. Gas diffusion is much faster than that and this means that nearly all the O2 that you have in the cylinder will uniformly diffuse into the headspace within an hour or less. At that point fermentation CO2 will have to progressively scrub the O2 from the headspace and depending on how far fermentation has already progressed this could very likely result in residual O2 levels that are significantly higher than what they would have been had no O2 been introduced after fermentation began. Granted this will still be better than opening up the fermenter but still much worse than using bottled CO2 with at worst 50ppm residual O2 since with your method you'll be introducing exactly the same volume of gas to the fermenter but with about 210,000ppm of O2 or 4,200 times more.

 

[mongoose33]

That is wrong and I've already pointed it out to you several times. Just download the specs for food grade CO2 from the major suppliers and you'll see that they guarantee at most 50ppm of residual O2, at best as little as 20ppm. That's a far cry from 0.5% or 5000ppm. If 50 ppm is still too much for you could purge the hopper with a high vacuum pump and skip the last pressurization step. If you drop residual pressure down to a few millibar and then crack open the valve letting headspace gas fill the cylinder you'd hardly have introduced any residual O2 from your bottled CO2.

As for keeping the O2 out of the headspace with your method the problem is that fermentation only creates a very slow flow of CO2, way too slow to mechanically purge the cylinder. Gas diffusion is much faster than that and this means that nearly all the O2 that you have in the cylinder will uniformly diffuse into the headspace within an hour or less. At that point fermentation CO2 will have to progressively scrub the O2 from the headspace and depending on how far fermentation has already progressed this could very likely result in residual O2 levels that are significantly higher than what they would have been had no O2 been introduced after fermentation began. Granted this will still be better than opening up the fermenter but still much worse than using bottled CO2 with at worst 50ppm residual O2 since with your method you'll be introducing exactly the same volume of gas to the fermenter but with about 210,000ppm of O2 or 4,200 times more.

We're going to have to disagree here. I asked my supplier of CO2 about this and the numbers I quoted are what he told me. So maybe there are places where you can get super-pure CO2. My local supplier isn't one of them.

As for the rest, again, we'll have to disagree. I don't think my numbers are incorrect. The math is right, I believe, and the logic as well.

And I surely cannot see how you think I'm introducing more than a miniscule amount (if that) of oxygen into my system. Perhaps a reread of what I do might be in order.

 

[Vale71]

We're going to have to disagree here. I asked my supplier of CO2 about this and the numbers I quoted are what he told me. So maybe there are places where you can get super-pure CO2. My local supplier isn't one of them.

As for the rest, again, we'll have to disagree. I don't think my numbers are incorrect. The math is right, I believe, and the logic as well.

And I surely cannot see how you think I'm introducing more than a miniscule amount (if that) of oxygen into my system. Perhaps a reread of what I do might be in order.

So you don't think that O2 will diffuse quickly into the headspace but believe that it will stay in place and be pushed out by fermentation CO2? I'm sorry but that idea is completely wrong. As it's not a matter of opinion there is nothing on which to agree or disagree. Behaviour of gases has been known rather well for over 200 years, there is no need to reinvent anything. Your math may be right but your understanding of the underlying physics is simply wrong leading to incorrect results.

As for your supplier claiming 0,5% air in the gas he either doesn't know what he's talking about or he's purposefully contaminating his stock to reach such high levels. I would ask him for a spec sheet or at least the name of his supplier so that you can ask them directly. In any case I don't see according to which logic one could consider using air with 210,000ppm oxygen les crititical than using bottled CO2, even assuming the latter could have 10,000ppm oxygen as you incorrectly claim. After all 210,000 is stil 21 times more than 10,000 or is my math incorrect?

 

[Rainy]

So you don't think that O2 will diffuse quickly into the headspace but believe that it will stay in place and be pushed out by fermentation CO2? I'm sorry but that idea is completely wrong. As it's not a matter of opinion there is nothing on which to agree or disagree. Behaviour of gases has been known rather well for over 200 years, there is no need to reinvent anything. Your math may be right but your understanding of the underlying physics is simply wrong leading to incorrect results.

As for your supplier claiming 0,5% air in the gas he either doesn't know what he's talking about or he's purposefully contaminating his stock to reach such high levels. I would ask him for a spec sheet or at least the name of his supplier so that you can ask them directly. In any case I don't see according to which logic one could consider using air with 210,000ppm oxygen les crititical than using bottled CO2, even assuming the latter could have 10,000ppm oxygen as you incorrectly claim. After all 210,000 is stil 21 times more than 10,000 or is my math incorrect?

And what about letting pressure (15psi) build up in the fermenter with the butterfly valve closed, loading the dry hop cylinder with hops, putting a spunding (set at 10psi) valve on the top of the dry hop cylinder, and then slowly opening the butterfly valve to have a slow steady flow of CO2 from the fermenter go through the dry hop cylinder. Most likely there will be too much mixing of the CO2 with the air in the cylinder, but if the flow of CO2 can be controlled to be slow (by adjusting the spunding valve pressure closer to the pressure in the fermenter) mixing could be reduced. This would then flush the dry hop cylinder of CO2 within a matter of a minute, hence diffusion not coming into play.