the tale of two kegs - help!

So… I have only kegged five beers and two of them were undrinkable. I purchased one of those new Italian kegs first and then two months later I purchased a used keg. The used keg smelled fine and I cleaned it out with PBW and then plenty of fresh water. I tasted the water that came out of the keg and it didn't have any taste at all. I then sanitized the keg and siphoned a batch of beer into the keg. I set the keg at 12 PSI for three weeks while I drank my other keg. When I first tasted the used kegs beer, it tasted fine but with a very faint metallic aftertaste. As time when on, the metallic flavor got stronger and stronger. I eventually dumped the keg, when I opened the keg there was no visible infection and it just looked like beer.
I again cleaned the keg out with PBW, flushed with fresh water, tasted clean water and sanitized the keg and put another batch of beer in it. Set it at 12PSI for three weeks before touching it. Again, the beer had a slight metallic bite and got worse over time to where it was undrinkable. I dumped this batch and again, there was no visible infection.

Incidentally, I have had two other batches in the new Italian keg with no metallic taste and everything was great. I use the same C02 canister, regulator and air hose for both kegs. I set all my beer at 12PSI for three weeks before drinking them. Basically, I do the same exact thing for both kegs.

Does anyone have any idea what is going on? Can old kegs leech metallic taste into beer? I am open to all suggestions but I don’t want to waste another batch of beer.

It sounds like carbonic acid and over carbing.

What temp is your kegerator/fridge and what type of beer is it?

You can fix it. In my case I turned off the gas to the keg, purged a couple times a day for 3 days and set at lower psi.

Worked like a charm.

JoeSpartaNJ said:

It sounds like carbonic acid and over carbing.

What temp is your kegerator/fridge and what type of beer is it?

You can fix it. In my case I turned off the gas to the keg, purged a couple times a day for 3 days and set at lower psi.

Worked like a charm.

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The keezer was set to 49 degrees and both kegs were in there. The "new" keg did not have that flavor. They were both brown ales.

It sounds to me like the beers picked up an infection before they were kegged (or perhaps as they were being kegged), and it's just a coincidence that the two infected batches went into the same keg. I don't believe stainless steel leeches any kind of metallic flavors into food - that's why it's used so prolifically in the food/beverage industry.

Check all the fittings, and fully inspect the inside of the used keg.

"METALLIC
CHARACTERISTICS: A harsh, metallic taste noted both on the tip of the tongue and the roof of the mouth. Can be felt throughout the tongue and mouth in large concentrations. Not desired in beer. Also described as tinny or bloodlike.
CHEMISTRY: The ferrous ion (iron) and some organic compounds formed by hydrolysis of cereal lipids in grain, and oxidization of free fatty acids.
HIGH RATE FROM PROCESS: Iron or mild steel in contact with beer; freshly-scrubbed stainless steel that has not been allowed to oxidize; improper filtering material; high iron content in water; poorly processed grain.
REDUCTION: Use of stainless steel; low-iron water; use of citric acid to re-oxidize stainless that has been abrasively cleaned; use of filtering materials that are acid-washed to remove iron; use of fresh, high-quality grain malt. "

or
Metallic
Tastes/Smells Like: Metal, mainly iron, also described as tasting like pennies or blood, Felt on the front of the mouth and back of the throat
Possible Causes: Wort being boiled in unprocessed metals, mainly iron, but also aluminum, and steel (excluding stainless) is usually the source of metallic flavors. Metallic flavors can also be extracted from metal brewing equipment, bottle caps and/or kegs. Using water that has high levels of iron will impart iron flavors. Improperly stored grains can also cause metallic off flavors.
How to Avoid: Use stainless steel pots and brewing equipment (fittings, spoons, etc.) when possible. Avoid using iron for anything that will be coming in contact with beer/wort. If using a ceramic coated steel pot, always check for cracks or scratches before using. Stainless steel will not give off any metallic flavors. Aluminum pots will generally only cause metallic flavors when using alkaline water with a pH over 9. If using an aluminum pot, you can “bake” the pot in an oven at 250ºF for 6 hours to increase the protective oxides. Always use fresh, properly stored grain. Avoid using water with iron in it, such as unfiltered well water.

You could have a fitting in the keg that's been changed out for one that's NOT stainless steel. Inspect the dip tubes and everything else you could change in it. Also look for any rust inside the keg. You might need to get an inspection mirror, if you don't already have one (doesn't everyone?)...

Have you torn down that keg? Taken the poppets out and everything? What about racking? Did you use the same racking equipment for both new and old kegs, good and had batches? What was the time line? Were both bad batches racked after the good batches or before?

Oh wow. What he said right before me.

It's possible one of the dip tubes in the used keg isn't stainless steel. Could be aluminum (you won't know until you check). Or you could have a rusty nut in there (ouch)...

As others have stated, tear the keg down replace all the rubber, after you clean with pbw you should passivate the stainless with acid. Star San will work fine. Fill it with star San and shake it around. I had a keg that actually had tiny spots of rust inside. After a star San bath for a week they were gone.

If you don't want to use Star San for the rust removal, you can also use a citric acid solution. Typically 1 cup per gallon of hot water does the trick. I use that as needed for items. You can get a 5# bag of citric acid powder on Amazon pretty cheap (just look for it). If you can get it locally for a better rate, do so. You can also mix it up stronger if you really want to. Although the cup per gallon ratio is on the strong side already.

Just a couple of notes -

I did not replace the poppets but I did replace all rubber O-Rings. The beer was transferred at different times and good beer after bad. I transferred with the same equipment.

Thanks for all the info!

Questions:
How do I tell if the dip tube is aluminum?
Why wouldn't I use star san for the acid wash?
What about putting water in the keg for a week or two and see if the metallic taste comes back?
I know how to get poppets, but how do I purchase new dip tubes?
Where would I see a nut that would be rusted?

I just ordered an inspection mirror.

Your dip tube won't be aluminum, I have never seen one.
There is no reason not to use star San. Nitric acid is the best for stainless, but phosphoric(starsan) will work fine. Make it a bit on the strong side.
It would be a good idea to carbonate some water and leave it for a week, after you do the acid rinse just to check for the flavor again
you shouldn't have to purchase new dip tubes, but removing them and cleaning the inside with a dip tube brush would be a good idea.
You shouldn't see any rusted nut. But weird stuff does fall into kegs and can get stuck in there so give a good look.
Also check the outside along the seams for any weld repair, sometimes a sloppy job was done and the inside didn't get ground down or has slag present and could be rusting.

JRems said:

There is no reason not to use star San. Nitric acid is the best for stainless, but phosphoric(starsan) will work fine. Make it a bit on the strong side.
It would be a good idea to carbonate some water and leave it for a week, after you do the acid rinse just to check for the flavor again

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I will try this and report back.. thanks for the help!

So, I tried the test with water and after being kegged for nearly two months, the water tastes just like water. No, odd or off flavors at all.

So, two days ago I decided to keg my most recent beer in the "good" keg (the one I had no issues with). I tasted the beer before I kegged it - was good, complex, nice hop flavor and aroma. Temperature was at 40, set the regulator to 9 PSI (I have 10 foot lines attached to a party tap). I decided to try the beer yesterday evening - smell was a little bit like the bad keg, no hop aroma, no hop taste taste was similar to the "bad" keg - mostly bitter. I am not sure if I would call it metallic at this taste but it was definitely not like the pre-kegging taste.

I am quite frustrated as this will be the third batch of beer that I might possibly throw away. I really want to have kegged beer but not if I keep having this problem.

I really don't know what to do at this point...

Change the taps and lines. Check the swivel nuts (if you're using them). I'd even used fresh QD's to the kegs. Is your CO2 tank steel or aluminum??

Golddiggie said:

Change the taps and lines. Check the swivel nuts (if you're using them). I'd even used fresh QD's to the kegs. Is your CO2 tank steel or aluminum??

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I have already been looking at lines - do you have a recommendation? I am hopefully getting a perlick tap for xmas.

What should I check on the swivel nuts? - I do use them..

CO2 tank is aluminum.

scottvin said:

I have already been looking at lines - do you have a recommendation? I am hopefully getting a perlick tap for xmas.

What should I check on the swivel nuts? - I do use them..

CO2 tank is aluminum.

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If the tank was new when you got it, and filled by a good place, you should be fine there. Since you didn't have the issue at the start kind of rules out the CO2.

If you're going to a Perlick tap(s) then get 3/16" ID Bevlex tubing to connect. Maybe get a new set of swivel nuts for the lines. With not knowing (couldn't find it in previous posts) what tubing you're using it could be coming from there. Or one of the lines has something wrong with it. If you have the patience, you could try filling the issue line with Star San solution for a day, or two, then connect it back up and push it out with beer.

Have you been cleaning (fully) the hoses between batches? I push hot PBW through, followed by rinse water, followed by fresh Star San (2-3 quarts of each). Never had any issue in many keg changes. Of course, I'm also using Perlick stainless taps (have been from early on). I think I used the picnic tap for one keg before changing over.

The keg was new when I got it. However, I got a refill at another location near my house. That's when the problem started to occur (3 out of 5 batches were bad, 2 were good). I bought this line -> http://www.austinhomebrew.com/product_info.php?products_id=1210 and this line -> http://morebeer.com/view_product/16366

Where can I find 3/16" ID Bevlex?

My cleaning procedures for the lines are - flush with water, flush with Oxyclean Free, flush with water, flush with Star San, flush with water and leave the water in the line.

scottvin said:

The keg was new when I got it. However, I got a refill at another location near my house. That's when the problem started to occur (3 out of 5 batches were bad, 2 were good). I bought this line -> http://www.austinhomebrew.com/product_info.php?products_id=1210 and this line -> http://morebeer.com/view_product/16366

Where can I find 3/16" ID Bevlex?

My cleaning procedures for the lines are - flush with water, flush with Oxyclean Free, flush with water, flush with Star San, flush with water and leave the water in the line.

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I use this line for my beer. I also use the red (5/16" ID) line for the CO2 on my system.

For the cleaning, get some PBW and use this method.
Warm/hot PBW pushed through line (via keg that's kicked). Push 2-3 quarts through.
Rinse out keg, put ~2 gallons cold water, in and push 2-4 quarts through beer line.
Put ~1 gallon of Star San into keg, coat entire inside, and push 2-3 quarts through beer line.
Connect to ready keg and push Star San solution out with beer.

DON'T rinse the lines once you've run the Star San into/through them. You could be getting off flavors from the water you leave in there. I would also use either filtered, or good clean water for all this (distilled from the store could be a good option now).

Are you on city water or well water? If you don't have a filter setup on either, I would get one. Even though the city water where I live now is good, I don't consider it good enough for me to use in cooking, drinking, or brewing. I filter ALL the water I use for those purposes.

I will get some of that line to see if it helps after I get my perlick (hopefully!).
I will also follow your instructions for cleaning the lines.

I am on well water and use the following for a filter -> http://www.walmart.com/ip/Camco-Water-Filter-with-Hose/14504321

scottvin said:

I will get some of that line to see if it helps after I get my perlick (hopefully!).
I will also follow your instructions for cleaning the lines.

I am on well water and use the following for a filter -> http://www.walmart.com/ip/Camco-Water-Filter-with-Hose/14504321

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Ummmm, yeah.. "100-micron fiber filter" IMO, just shy of useless.

My filter system. Goes under the sink with the spout coming up through a hole (usually a spray hose, but you can also make a hole for it alone). Goes down to the .2 micron size filter.

This would be a good second choice. Comes with down to a 1 micron filter size. I'm pretty sure you can also get .5 micron filters that work with that housing size.

sorry, I don't know why I typed well, I meant city water.

Either get the better (or rather useful) filter or go with all bottled water. IME, the filter is more up-front cost, but your cost per gallon is a LOT less. On the order of maybe a few cents per gallon versus $1/gallon (or more).

I am sure that would make things better but I don't believe that is the cause of the odd taste as bottled beer is fine. However, I will look into the filter.

scottvin said:

I am sure that would make things better but I don't believe that is the cause of the odd taste as bottled beer is fine. However, I will look into the filter.

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IMO, leaving the water sitting in the line is at least part of it. Actually, it could be all of it. Water quality is an important factor. Also, a 100 micron filter is about as useful as cheesecloth to filter water.

Well, it is certainly my lines. I did a test last night - purged the keg, took a sanitized sample of the beer from the keg. Closed the keg back up and then took a pour off of my tap.

Straight from keg sample tasted fine.
Poured from tap sample tasted like plastic/vinyl.

Well, at least I know that the keg isn't the problem. I am going to clean my current line with the above procedures to see if that helps. I am also going to purchase the suggested line as well. How can they sell beer lines with issues like this? I assume most people have these problems as well.

scottvin said:

Well, it is certainly my lines. I did a test last night - purged the keg, took a sanitized sample of the beer from the keg. Closed the keg back up and then took a pour off of my tap.

Straight from keg sample tasted fine.
Poured from tap sample tasted like plastic/vinyl.

Well, at least I know that the keg isn't the problem. I am going to clean my current line with the above procedures to see if that helps. I am also going to purchase the suggested line as well. How can they sell beer lines with issues like this? I assume most people have these problems as well.

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They can sell the lines like that because most people either won't know the difference, won't care, or the beer going through them won't pick up the flavors (enough other flavors to hide them). Of course, you could have just gotten part of a bad lot too.

Where did you get the lines/setup from originally?

I got one set from morebeer and one set from austin homebrew

I switched to Accuflex Bev-Seal Ultra lines after struggling with off flavors in my kegged beer, similar to what you describe. It's kind of expensive, but I can enthusiastically recommend it. Bev-Seal Ultra is lined with a flexible glass barrier that imparts no taste whatsoever.

Birdman Brewing sells it in manageable quantities:

http://www.birdmanbrewing.com/accuflex-bev-seal-ultra-barrier-tubing-3-16-id-50ft-free-shipping/

I prefer to flush the lines with PBW between kegs, but sometimes I get lazy and don't. Even then, I don't notice any flavor carryover from one batch to the next.

I've not had any issue with the lines from Keg Connection... Not saying to not get the Accuflex, but I would try one with the Keg Connection hose first.

If possible, try to figure out which one you got from which company, then send them an email with feedback. IMO, if you don't then they won't know there's an issue either with the product (they could have switched) or the lot they got.