Devil bacteria in Corny kegs

[Old_mil_guy]

After really cleaning the corny and replacing every oring, how about dropping a campden tablet in before transfering beer?

 

[okiedog]

Is there a lab that you can send samples off too and get results for an affordable price?

 

[pjj2ba]

The only thing I haven't done so far is to attempt to sterilize with boiling water, bleach and water solution, or steam/ autoclave (to which I have no idea how to accomplish it even if I wasn't afraid it would render the attached rubber/ plastic completely useless).

Just for the record, kegs are autoclavable! Some rubber tops get softer than others temporarily while hot, but I've not had a problem doing this. Once they cool I've had no issues with the handles - or poppets, or any seals.

I'd give a serious look to everything you use, not just the kegs, in your search for the source of contamination.

 

[Aloha_Brew]

Speaking of the sulfer/sweet taste, that may be because the pitching temp is too high. It lowers the amount of yeast cells from developing and start to cause the cells to produce a lot of waste that cannot be eaten up later in the conditioning phase because they spent too much time early in the initial pitching trying to eat sugars instead of dividing like they are supposed to. Try pitching at a lower temp and let it gradually come up to the desired temp. The yeast cells will then be able to acclimate to the environment, divide into a ton of healthy cells which will be important later when they are able to eat much more complex sugars and waste products from earlier cells.

I'm fairly sure that it's the amount of yeast that I have been pitching, or the lack thereof, that is causing the sulfur taste. I'm not too sure about the diacetyl though, whether that is increased by the supposedly stressed yeast or if I'm somehow introducing too much oxygen during my whole brewing process. I got another thread that had addressed this topic.

 

[Aloha_Brew]

A couple things to ponder on:

If it really does taste like vinegar, the metabolic pathway that turns alcohol into acetic acid is an aerobic one. Depending on various degassing methods many vintners have a tendency to aerate their wines to some extent post primary, but this rarely turns said to vinegar. Acetobacter / Mother of vinegar is basically on everything and is extremely tolerant of low PH, thats why wine makes use sulfates and not starsan in their sanitation processes. Acetobacter shouldn't ruin a beer unless it's severely oxidized. If you're force carbonating with bottled CO2 and purging all the air out of the keg before hand, it's unlikely to be acetobacter.

If it doesn't taste like brett or lacto, you could consider the possibility that the steel of your keg has become porous somehow and is leeching out some nastiness that it dissolved during storage. The fact that the flavor comes out gradually and cleaning and sanitizing doesn't fix the two out of three that are effected could point to leeching.

Well that would just suck, as it sounds as if I can't do anything to stop this leeching process from occuring again in the future... I'm hoping that such a situation does not apply to me, but I will keep on eye out for a reoccurance. I can only think that I didn't replace the poppets and relief valve on the removable cover before and that's what was causing it. I've changed those out with new ones, spending a pretty penny altogether, and would hate to think that I would have been better off just buying a new keg.

 

[Aloha_Brew]

After really cleaning the corny and replacing every oring, how about dropping a campden tablet in before transfering beer?

I bought campden tablets for future cleanings, after each use, but I figured if bleach/ boiling water/ PBW/ StarSan didn't solve the problem then a campden tablet would not have been able to do much more. Before I transferred beer into the kegs a few days ago, and after the StarSan question I asked a few posts ago, I did not notice any further sour/ vinegary smell. It had not been sitting for long with any exposure to air for any long period though. I'm hoping I fixed the problem and I'm back to active prevention rather than actively combating another infection.

 

[Aloha_Brew]

Well, it would seem as if all my efforts were for nothing. I have been dispensing my recent pilsner over the last four days and yesterday noticed a slight "huskiness" (the best way I can describe the onset) to it. Today it had less huskiness and more of a malt vinegar bite and smell. It is definitely still drinkable and I will "monitor" the severity of the taste over the bext couple days, but I fear the worst.

Once I'm done with this keg I'll try my Helles and then the Dopple, just to make sure the infection didn't also end up in them. I believe that I will have to cease my brewing for the next couple months, or at least the kegging, to save up for brand new kegs. I've done all I can and I can't think of anything else I could possibly do that wasn't covered in some other fashion by my previous efforts.

A side note: when I bought the kegs they were definitely used, having surface scratches and dents as well as similar evidence if use on the inside. I don't know why this problem has only manifested in two of three (only one of the two I had shipped from kegconnection, and the one I had purchased from my local HBS) but I fully understand that the infection SHOULD NOT be living in the keg and originated from outside; as I've not found any evidence of leaching in steel kegs that imparts the same type of flavor I have, increasing over time and only manifesting after 6 months of use. So, I will save up and buy some brand new kegs and dispensing hoses.

Thanks for all the advice guys, and I truly hope that all of you and myself will never experience such crap ever again.

 

[certaut]

never use bleach on stainless, unless you plan to polish and re-pacify.
Oxy clean will leave a film unless you rinse and use a 3m as you are rinsing.

1/2 gal of warm water and 1/4 cup of lye will clean any residue from stainless (it's dangerous so protect yourself) you can dilute it afterwards and distribute in your drains and it will kill off the drain fly's

full strength muriatic acid will re-pacify stainless. Wear proper protection and use the rinse to remove the oil stains in the driveway or bump off the fire ants.

After you are satisfied that they are squeaky clean replace the o rings (don't forget keg lube) dump a couple of quarts of star san in put the lid on and shake it around. Pressure up to 30 lbs and purge (if you invert the keg and purge a little it will do the relief valve) hook up the liquid line and drain the rest through the tap

 

[Aloha_Brew]

Reading John Palmer's "How to Brew," as mentioned before, he didn't mention anything about re-pacifying. I understand how that could solve the problem if it really was leaching, but I am not tasting any metalic flavor. It is a distinct souring that is closer to malt vinegar than anything, especially as it sits in the keg. It also is not affected by a "lack" of oxygen, as I carbonated before serving by slowly bleeding CO2 while the relief valve was up for about 30 seconds and then released full pressure twice at 17psi.

I've never dealt with those chemicals before either and would not feel that it would be cost-effective/ worth the time/ beneficial with my particular situation. If I was a brewery, I might have to deal with that, but with all that I've done so far I sincerely doubt that any more effort (regardless of the agent being used to "clean" or "sanitize") will yield any more success. I might just as well try and find an autoclave that some business or individual owns on the island and ensure 100% sterilization. But again, that would probably be costly and I know about as much as where to find an autoclave as I do those chemical agents.

It would be far easier, and probably just as costly, to just buy new equipment. Something has to be in those kegs that isn't letting go, and there is no explanation I have as to why it is even possible that it is remaining there but all evidence points to that conclusion. I'm just tired of spending time and money trying to fix something that's already broken, even though it would be beneficial for me to understand how to eradicate such a problem that might occur again in the future.

Replacing o-rings and StarSan have also not solved this particular problem, to include replacing poppets and relief valves. I wholeheartedly agree that everything everyone has recommended is good practice and what I have done should have fixed the problem. Unfortunately, it has not and I am not hearing from anyone who has had a similar experience; so, I must conclude that this is something out of the ordinary and likely involves no solution that anyone has discovered themselves.

As for sending it off to a lab, I just might go ahead and do that. That would be more worthwile in my opinion, in order to get an expert opinion on what else I might have tried or what I could have done to prevent such an infection. I think White Labs might be able to help, but anyone who has any other suggestions for this type of thing please feel free to share.

 

[IslandLizard]

Maybe destroying them would be the last and perhaps best solution.

Just to review:

Did you thoroughly scrub and clean the inside of the dip tubes with stiff brushes? And all the nooks and crannies inside the kegs and lids? The most likely places for dirt to hide out is where you can't see it or get to.

There is a possibility those kegs in question are gauged in a place where you can't see it, like right under the top, or have a bad weld, crimp, or dent that harbors dirt and the tenacious bugs. Even autoclaving won't be a permanent solution if that's the case.

If you have one, stick a USB camera in them to inspect those areas.

Remember, a dirty surface cannot be sanitized, whatever you do.

I'm sure there are ways to test them without filling them up with good wort. Simple "sterile sugar water" as a test liquid should get infected too.

Good luck with your research project.

 

[Aloha_Brew]

I can see the weld between the cylinder and the top itself and I tried to clean it as best as I could, but I can only feel the weld where the dipsticks connect. I did clean them with brushes and with a soft scouring pad (the fibrous type of threaded material and not like a green scouring pad or steel wool). One of the kegs looked like a very odd looking weld but I couldn't see any major crevices that might harbor material.

Just extremely worn out that these beasties keep coming back...

 

[JRems]

If you cleaned it that well it has to be getting contaminated prior to going into the keg. Maybe a gas line or gas disconnect is contaminated.

 

[eastoak]

i think the contamination is happening before the beer gets into that now "most sanitized keg in the world". you could test this by giving the keg to a buddy who brews and let him/her rack a beer into the keg and see what happens. when i had a brewhouse infection that kept popping up in all of my brews i threw nothing away. i took all of my plastic materials washed them, put them through a bleach water bath then rinsed. i did this twice in one day then let everything dry before putting it away. that was almost 2 yrs ago and since then i've been brewing clean and sour beer using the same equipment (including kegs which i've never replaced any of the gaskets or taken apart for cleaning of individual parts) and have never had a cross contamination.

 

[JuanMoore]

If you cleaned it that well it has to be getting contaminated prior to going into the keg. Maybe a gas line or gas disconnect is contaminated.

Even if the keg isn't being cleaned/sanitized that well, the transfer tubing and other things that contact the wort between primary and the keg are much more likely culprits than the kegs themselves.

 

[Redcat]

You can re-passivate stainless steel with Lemishine from Wal-Mart.

Lemishine is a citric acid used to clean the insides of dishwashers. I'm not sure what the mix would be for a corny keg, but I would take a look at that option.

 

[FATC1TY]

Man.. all the talk of this cleaning makes me feel like I'm some chump in cleaning my kegs. I've never had a problem *knocks of wood*.

I empty a keg, and keep it in the keezer usually, unless I REALLY need the room for something waiting. When I have time, I'll degas it.

I rinse it all out with the water hose, get the cake out of the bottom and the hop debris from dry hopping in there.

I'll heat up the water kettle, and get some hot water in there, with the PBW. Shake it around.. Generally, there's nothing to scrub, so I don't bother. I'll wipe down the posts and clean the top of the keg when I remove the label of what it is.

Shake that, hit it with a tiny bit of gas. Will hook up my tap lines, and run them through with the PBW, to clean them, and the dip tube. Dump it, hit it with more hot plain water to flush. Repeat dispensing process.

Rinse it with cold water... Leave some in there, and add some star san.. Shake it around and let it sit.. run it through the dip tube via gas, and dump it all before I put more beer in there.

Seems simple enough, and no real issues.

 

[Aloha_Brew]

Man.. all the talk of this cleaning makes me feel like I'm some chump in cleaning my kegs. I've never had a problem *knocks of wood*.

I empty a keg, and keep it in the keezer usually, unless I REALLY need the room for something waiting. When I have time, I'll degas it.

I rinse it all out with the water hose, get the cake out of the bottom and the hop debris from dry hopping in there.

I'll heat up the water kettle, and get some hot water in there, with the PBW. Shake it around.. Generally, there's nothing to scrub, so I don't bother. I'll wipe down the posts and clean the top of the keg when I remove the label of what it is.

Shake that, hit it with a tiny bit of gas. Will hook up my tap lines, and run them through with the PBW, to clean them, and the dip tube. Dump it, hit it with more hot plain water to flush. Repeat dispensing process.

Rinse it with cold water... Leave some in there, and add some star san.. Shake it around and let it sit.. run it through the dip tube via gas, and dump it all before I put more beer in there.

Seems simple enough, and no real issues.

Ah, the good old days...

What's really killing me is the two out of three kegs. If it's a true problem outside of the kegs then it should have popped up in that last keg by now (more than six months and about 9 batches already!). I've shared the same sanitation practices with all three kegs and associated tubing. That's why I can only conclude that it is the kegs somehow that are the cause and replacing them the solution.

 

[scottland]

Any chance some beer back flowed into your co2 tank or regulator? And now it's dispensing some skanky co2?

 

[JRems]

Any chance some beer back flowed into your co2 tank or regulator? And now it's dispensing some skanky co2?

That was my thought as well. I took apart some of my gas and beer disconnects and was startled to see crap even inside the gas disconnect. I just took them apart and boiled them.

 

[eastoak]

Ah, the good old days...

What's really killing me is the two out of three kegs. If it's a true problem outside of the kegs then it should have popped up in that last keg by now (more than six months and about 9 batches already!). I've shared the same sanitation practices with all three kegs and associated tubing. That's why I can only conclude that it is the kegs somehow that are the cause and replacing them the solution.

it is sound logic but whatever it is could have been present for a long time, getting knocked back periodically but always persisting. it would be interesting to see if another brewer would be able to rack a beer into that keg and not get an infection, that would truly tell the tale.

 

[okiedog]

I don't know what they charge, but Wyeast will do infection analysis for you. You could take a sample from the gas line, and a sample of the beer or of the white contamination in the keg. It could save you a lot of work (if not money) to get a definitive answer.

 

[Aloha_Brew]

I got in touch with White Labs, who also does analysis, and they basically recommended to try and solve the problem rather than spend money shipping the sample to find what bacteria are there. I described the problems to them and they seemed to agree that it was Acetobacter, or something called Pediococcus. I don't it think it can be the gas lines, as out of the three kegs I recently had after the thorough cleaning I only noticed the taste in the first one I tapped, and only two of the three previous to that.

After further analysis of my two remaining kegs I think it likely that the problem that resurfaced in the first one after the cleaning was likely residual. I changed out my tap lines after the first keg was done, starting the new one with the second keg, and noticed a slightly similar sourness but on a much lesser scale. Also, the first keg did have a distinct souring/ vinegar taste like before but it did not develop into a much greater problem as it had before.

The first keg had a Pilsner, the second a Helles, and my third a Dopplebock. The funny thing is that the third one was one of the original two that had the original problem. I had left it lagering for nearly two months though and it has no hint whatsoever of any sour/ vinegary taste. I'm at a loss, but I'm definitely drinking everything up!

I will, of course, heed the advice of all of you and disassemble my gas lines and regulators (as I have 2 sets) though. I will also look into the Lemishine from Wal-Mart to refortify the kegs, instead of spending hundreds on new kegs. The problem seems at least to be slowly working its way out of my production line, if not already eradicated. Here's to hoping! For the true deliciousness of my dopplebock I thank you all for your help and hope the demons are exorcised, never to return again. I should also hope nothing like this happens to anyone here, as it is a true beast that feeds on the beer before you can.:cross:

 

[Aloha_Brew]

The other day I was tasting my dopplebock and it tasted fine but I decided to up the CO2 pressure to give it some more fiz. After doing so I noticed that a familiar sour/ sulfur taste, so yesterday I took apart my gas lines and the connections. I noticed in the ball-lock connections a small collection of caked on goop, and took off the lines from my double-ball valve isolation block to find the teflon washers there were stained from the same goop. I cleaned everything as best as I could and then sanitized everything, so I hope this is the last of the matter.

However, I could not easily open up the regulator or the hose between the it and the double-ball valve isolation block. So, my question is should I even bother trying to delve further into that portion or do I risk potentially breaking the regulator by doing so? Anyone ever take one apart before? Also, since blowback seems to have somehow gotten all the way up the hose over the last year or so would it be feasible to install some sort of filter, if one even exists for that sort of thing? Any additional help regarding these questions on this long drawn out problem will, of course, be once again greatly appreciated.

 

[JuanMoore]

If there's a chance that you have more nasty gunk in other components of the gas system, then it's absolutely worth taking it all apart and cleaning. Regulators aren't that hard to disassemble. Just be organized and keep track of where everything goes (don't let the spring get loose), and be careful with the diaphragm. They're relatively simple and only have a few parts.

What you need to prevent backflow is a check valve for each gas line, not a filter. Inline check valves are cheap insurance at only ~$2-3 each. I use the ball and spring style from us plastics.

 

[Aloha_Brew]

I'm not sure how a check valve would help in my case, as I always have my gas valve open to provide constant pressure for dispensing. From what I know of check valves, they only work when the pressure on the opposite side of the source (in this case, the keg with beer) is greater, to protect the source (the gas source). Beer isn't being pressurized back into the line but is rather being sucked in due to the differential pressure occurring, only when I initially pressurize or dispense I'm guessing since I see no other way this would occur. Unless I'm totally misunderstanding things, I believe what I need is a filter to provide a constant boundary so that beer does not travel into the line at all.

 

[JuanMoore]

Yes, you're totally misunderstanding things.

Beer isn't being pressurized back into the line but is rather being sucked in due to the differential pressure occurring, only when I initially pressurize or dispense I'm guessing since I see no other way this would occur.

This makes zero sense. Yes, it's a pressure differential causing the flow, meaning that the pressure on one end is higher than on the other end. You can think of it as either the lower pressure on the regulator side creating a relative vacuum and "sucking" things towards the regulator, or as the higher pressure on the keg side pushing things towards the regulator, but it's the same thing.

From what I know of check valves, they only work when the pressure on the opposite side of the source (in this case, the keg with beer) is greater, to protect the source (the gas source).

Yes, that's exactly how they work. A check valve, when functioning properly, only allows flow in one direction. When the pressure on the gas tank side is higher than the pressure on the keg side, the valve opens and allows gas through. When the pressure on the keg side is higher than the pressure on the tank side, the valve closes and doesn't allow anything to flow through. I'm not sure what type of filter you think would allow gas through, but not beer, and yet not completely clog and block all flow the first time beer touches it.

There are many types of check valves, but here's how ball and spring check valves work. With pressures equal on either side, the spring pushes the ball against the seat, closing the valve. As long as the pressure on the left is higher than on the right, the valve will remain closed. The pressure on the right has to be high enough compared to the left to push the ball against the spring hard enough to open it. The pressure required to do this is called the cracking pressure. The cracking pressure for the ones I use is 1psi, which means that with the regulator set to 13 psi, the keg pressure has to drop below 12psi before the check valve will open and allow gas through.

 

[Aloha_Brew]

What I'm saying is that a check valve may stop most of the problem I seem to be having with beer entering the line, but it cannot stop it all because the pressure can equalize between the line and the keg; this still allows beer dispersed by the introduction of gas to pass by a check valve. A filter though, would prevent any liquid from entering the pressurized gas line period, if only by soaking it up to the point of saturation, at which point it would not function well at all.

Truthfully, the fact that there is pressure at all should negate the need for either. I can only guess that I may have left the lines unpressurized and connected during one of the times I moved my kegs to another location.

I may have worded my response poorly but the fundamental premise is still there... Forgive me, as I'm a technician and not an engineer.

 

[JuanMoore]

What I'm saying is that a check valve may stop most of the problem I seem to be having with beer entering the line, but it cannot stop it all because the pressure can equalize between the line and the keg; this still allows beer dispersed by the introduction of gas to pass by a check valve.

No, I don't think you're understanding how check valves work. If the pressure equalizes, the check valve will remain in the closed position. See the edit above with the diagram added.

I promise you that check valves are what you need. There's a reason they're integrated into nearly every commercially sold CO2 distributor/manifold.

 

[Aloha_Brew]

Ah hah...eureka, and then some. Forgot about the fundamental fact that equalization with active resistance would result in the closing of the ball valve until pressure increased again on the gas side. I stand corrected good sir, and will now look for check valves as you have described. I've had four of my dopplebocks within 3 hours and yet I am still able to understand the mistake I have made. 'Tis amazing. Thanks for the help, and the re-education.

 

[JuanMoore]

FWIW these are what I use-

http://www.usplastic.com/catalog/item.aspx?itemid=24234&catid=956&clickid=searchresults