Another DA question regarding a metallic taste in keg

[NGD]

As stated, I feel this is somewhat a dumb a$$ question that I should have found the answer to by now. I've researched this question here and several other forums and still haven't found a concrete answer. Hopefully the info below with answer most questions.

Purchased a new keg/regulator from Northern early last yeast and have to date had 2 beers and a test batch of water in it.

Prior to the first batch of brew, it was soaked with Oxyclean, rinsed with hot water and sanitized with starsan by adding a gallon and sloshing around, then pushing up the dip tube and through the picnic tap line under pressure (C02).

First batch: Filled and burst carbonated at 35psi for 24 hrs then dropped to 12psi
Result: Heavy metallic taste, even after 3 weeks. Alot of drain pours

Second Batch: Disassembled, soaked with Oxyclean again, left in overnight with warm (105F) water. Rinsed with hot water (125-130F), reassembled and pushed starsan through again after spraying dip tubes prior to tightening. Filled with new batch of brew that tasted great out of the fermenter. Burst carbed at 20psi while shaking for 10 minutes then dropped pressure to 8-10 for a few days before sampling.

Result: Pretty much the same. Seemed like after the third pour it would lessen. Still tasted like a stainless steel chewtoy.

Third batch (All tap water): Disassembled and cleaned with a PBW soak in warm water (105F) for 2-3 hours, rinsed with hot water as usual, sprayed everything down with starsan as before and reassembled. I do put a tiny amount of silicone o-ring lube on the o-rings after I disassemble. Added water after emptying extra sanitized and let sit overnight with no pressure trying to rule out carbonic acid.

Result: Same metal taste. Added a few psi and waited a week. Still same issue.


At this point the keg has been inside cleaned thoroughly with bar keepers friend and rinsed then dried. My understanding is by doing this it will help with passivization. I have a batch of Alt-bier that's been fermenting for a few months that tastes great, but I'm really not wanting to bottle when I have a keg sitting around collecting dirty looks.

Any advice is appreciated.

 

[seatazzz]

From what you've said, that keg shouldn't be throwing off ANY off flavors, but your beer might. What equipment do you use to brew? What is your carbonation setup? What is your brew kettle made of?

Of course, it *could* be the keg. At this point I would take a penlight and fully inspect the inside; any dents? Rough spots? If the keg was "refurbished", maybe a weld gone wrong inside? Metallic flavors in beer (according to Jon Palmer) are mostly cause by iron leaching into it from somewhere in the process. I would fully inspect the inside of the keg, were I you.

 

[NGD]

From what you've said, that keg shouldn't be throwing off ANY off flavors, but your beer might. What equipment do you use to brew? What is your carbonation setup? What is your brew kettle made of?

Of course, it *could* be the keg. At this point I would take a penlight and fully inspect the inside; any dents? Rough spots? If the keg was "refurbished", maybe a weld gone wrong inside? Metallic flavors in beer (according to Jon Palmer) are mostly cause by iron leaching into it from somewhere in the process. I would fully inspect the inside of the keg, were I you.

Here is the actual keg setup I bought, although they appear to be more polished than when I purchased mine. https://www.northernbrewer.com/draft-brewer-single-keg-system

The C02 was filled at a local fire control supply. One thing I haven't considered until now is perhaps the gas supply is contaminated. Brew Kettle is a cheap stainless 5gal variety that comes with the Midwest Platinum Pro starter kit. Fermenting in plastic buckets ATM in a temp controlled kegorator.

I'll go through the keg this week and double check for bad spots. I'm fairly certain it isn't something prior to the kegging process, as I've made 2 batches of a belgian and a cream ale that have come out quite well, but were bottle conditioned. However I'm always willing to double check my process. Thanks for the suggestions

 

[Horseflesh]

I'd also suggest for next time putting some of the beer direct from the fermenter into a soda bottle and force carbonating it with a carbonation cap. That way you can compare the taste of cold carbed beer that's never touched the inside of the keg.

 

[kegtoe]

NGD, I'm wondering if I have a similar issue. My beers taste great out of the fermenter (other than being flat) once in a keg and under CO2. In get a strange taste. Not bad, just odd, and similar in all my beers. I am starting to think the CO2 I get is causing it. I recently changed ALL MY HARDARE on my keezer including draft lines to get rid of it, and it's still there.

 

[NGD]

I'd also suggest for next time putting some of the beer direct from the fermenter into a soda bottle and force carbonating it with a carbonation cap. That way you can compare the taste of cold carbed beer that's never touched the inside of the keg.

I had no idea those carbonation caps existed. It just made the list of things I didn't know I wanted but must order ASAP.

NGD, I'm wondering if I have a similar issue. My beers taste great out of the fermenter (other than being flat) once in a keg and under CO2. In get a strange taste. Not bad, just odd, and similar in all my beers. I am starting to think the CO2 I get is causing it. I recently changed ALL MY HARDARE on my keezer including draft lines to get rid of it, and it's still there.

If your anything like me, you've scoured the interwebs in search for an answer and come up with many suggestions and not many answers. Here are my thoughts on what it might be in my case.

• Sanitizer coming in contact with something brass. Although I did a through inspection of everything and haven't found any obvious culprits.
• CO2 is tainted-Most likely IMO
• My cleaning technique needs to be revised.
• O2 from not purging the keg enough is causing issues. As time goes on..the metallic taste gets worse, not better. Not sure if this is related. The taste goes from "Thats a little metallic" to "Did someone just shove a handful of coins in my mouth" over time.
  
• I'm exposing the beer to oxygen by leaving it in a plastic fermenter to long. I use buckets and typically just set and forget in my temp controlled mini fridge for 3-4 weeks.

Right now I'm leaning towards the C02 being bad as I get it filled at a place that does fire supply although I know of a few other brewers that use the same place and don't have any issues. I purged and kegged half a batch of Düsseldorf Altbier yesterday and set the regulator to 10psi. No rocking around to force carb this time. I'll let time do it's thing. First pull this morning did have a slight metallic smell, but no metallic taste I could detect. This brew is pretty malt forward though so I'll check again in a few days and see.

 

[lump42]

To help isolate the cause, you could also make a quick DME batch and naturally carbonate in the keg. add the sugar, at the time of kegging, and let sit just like bottle conditioning, don't connect CO2 until after you try the beer. Heck, you could probably add water, sugar, and a pack of bread yeast, may not taste great but cheaper.

 

[brew703]

Next time bottle a few, carbonate and check to see if the bottles have that same taste.
Seems to me that you have bad CO2 unless you have some rust spots inside your keg causing the issue.
Are you using picnic taps to dispense? if you are using regular taps, maybe take them apart, clean and run some BLC through your beer lines then rinse and sanitize.

 

[NGD]

Next time bottle a few, carbonate and check to see if the bottles have that same taste.
Seems to me that you have bad CO2 unless you have some rust spots inside your keg causing the issue.
Are you using picnic taps to dispense? if you are using regular taps, maybe take them apart, clean and run some BLC through your beer lines then rinse and sanitize.

I've been using a picnic tap with this keg since I purchased it. I did 12 bottles of this Altbier to compare to in a few weeks. Going to be interesting to compare the two.

To help isolate the cause, you could also make a quick DME batch and naturally carbonate in the keg. add the sugar, at the time of kegging, and let sit just like bottle conditioning, don't connect CO2 until after you try the beer. Heck, you could probably add water, sugar, and a pack of bread yeast, may not taste great but cheaper.

That's a good idea. I just picked up 4lbs of DME a few days ago for another batch I wanted to try. I haven't tried to naturally carbonate in the keg yet. Seems like that would definitely rule out most everything but the C02. Thanks!

 

[Konadog]

If you get a carbonation cap, try to carb up some water to see if the taste follows, if it does, it's the gas.

 

[seatazzz]

Hold the phone. You say you get your tank FILLED at the fire supply? No exchange? Bingo, there's your problem. It's the tank or possibly your regulator, but I'm betting the tank. Find somewhere that will exchange it for a different one and see if you get improvement.

 

[NGD]

Thought I would post an update. I’ve had the Altbier in the keg for 10-11 days now at 11psi. Its carbed up nicely and......tadaaa!! For whatever reason there is only a hint of metallic taste thats more like attributed to extract twang than anything. Not even a hint of the mouthful of pocketchange like I had the previous two batches.

I’m going to give the bottles another few days before I compare but I’ll update when I do. Only downside is now I really have no idea wth the original issue was with. I’ll just have to assume with zero proof that Bar Keepers friend was the missing ingredient to my cleaning routine.

 

[NGD]

One more thing of note. I carbed the beer slowly this time by putting the regulator at 10psi and letting the headspace fill. No force carbing at 30psi and shaking like crazy. I also tried to bleed off whatever 02 was in there by popping the pressure relief valve after an hour of so. The thought being that once the CO2 had time to settle the O2 would be at the top and eject out. I’m probably wrong in that but figured it couldn’t hurt.

 

[day_trippr]

The more time you wait the more thoroughly the CO2 and everything else would have mixed, but flushing the head space is never a bad thing...

Cheers!

 

[NGD]

One last update. Currently comparing the bottled and kegged versions.

The bottled version has less carbonation and definitely no metallic taste. Probably would have been better with one more carb drop (at least).

The kegged version is nicely carbed at 10-11psi and has just the faintest hint of a metallic taste. Its barely perceivable. After sampling both several times in the name of science; the wife and I agree its there. She prefers the kegged version.

I guess the takeaway from this is I never truly got the keg cleaned until I hit it with Bar Keerper Friend and let it passivate. I used it on everything inside the keg including the dip tubes.

Thanks to everyone that offered up advice. If I have any future problems I’m glad I can rescource this thread to troubleshoot.

Cheers!

 

[NGD]

If a mod could mark this thread as resolved, it would be greatly appreciated.