Off Flavor from New Kegs, Sanitation Issue?

I have two new kegs and when I filled my second keg after sanitizing, I shook the keg with the c02 hooked up to help dispense the c02 (I have only done the set it and forget it method by keeping the psi at 11). Then I tried a little sample of my double ipa and noticed a strong metallic bitterness which I did not taste prior to placing the beer in the keg. The first taste is fine but shortly after a strong lingering off flavor overwhelms your palate. I am a little perpelexed on how this got contaminated because I followed the same method of sanitation a month before and did not notice any off flavors. However, I have started to notice a similar metallic off flavor showing up in my first kegged beer, it is not as strong of a bitter metallic taste but it is noticeable.

The only thing I did different with the original keg was I hooked up a 4 way shutoff valve so I could have two kegs with one 5 lb c02 cylinder. Could an unsanitized shutoff valve cause an off flavor in the keg?

My sanitation method I used was I took everything apart and placed the small items in a bowl of sanitizer, then I filled the keg with 2.5 gallons of sanitizer. I had the keg stand upright for a few minutes before turning it upside in a bucket to sanitize the other half of the keg (I think I may not have successfully sanitized the top of the keg with this method which caused my beer to get contaminated when I shook it to dispense the c02). I also sanitized the dispensing tubing and picnic faucet in sanitizer along with the c02 lines (is this necessary to sanitize the c02 lines?). Then I hook up the keg pieces and dip tube before siphoning the beer in.

I plan to dump out the double ipa, luckily I bottled 13 bottles of it before kegging.

Could it be I just did not sanitize well enough? Are you suppose to use PBW and clean a new keg before using it?

Any advice would be greatly appreciated; cheers!

[quote=“Shenanigans”]Are you suppose to use PBW and clean a new keg before using it?[/quote]First scrub with BKF (barkeeper’s friend) to remove any residue, then do a PBW soak, rinse thoroughly, and follow with the StarSan. I put a gallon of StarSan in a keg, hit it with CO2 to seal, then shake and roll it for 30 seconds, set upright, and pull the pressure relief to push foam up through the valve and depress the gas poppet so StarSan gets in the diptube, too.

Take every thing apart and soak them in PBW then replace all 5 of the orings then sanitize.

Thanks for the advice! Is it common to have to change out o rings on a brand new keg?

I will soak everything in PBW then sanitize before adding my next batch of beer. However, I am still worried I may waste another batch of beer by having issues with my kegs.


For a “New” keg you should not have to replace the o-rings. Only on a “reconditioned” one.

I would think a good cleaning should be done even on a “New” keg. You never know how clean it could be. Only trust your work.

If I’m sanitizing more than 1 keg, I have a jumper (2 liquid disconnects) that I use to push sanitizer from one keg to the next.

If I’m only doing 1 keg, I push the sanitizer back to a jug for storage.

I only tip the kegs upside down a couple of times to sanitize the top.

Don’t rule out the beer for the off flavors. I’ve had metallic and bitter aftertastes from kegs AND bottled beer. I’ve had beer that seemed to develop them after a gravity sample. A little extra time helps! Especially a DIPA. If you are really going to blame the keg, don’t dump the batch. Bottle up what’s left and put it in the back of the fridge for awhile.

Any ideas why the first kegged beer did not exhibit a similar metallic taste until about a gallon is left? The only thing I did differently was hooked the c02 to a 4 way shutoff valve then I began to notice the off flavor.


Did you purge the keg of air before shaking the co2 into it?

Yes, I did purge the keg of oxygen by pulling the relief valve about 8 times while the c02 was hooked up.

I will hold on to the double ipa before dumping it to see if the harsh flavor decreases or, better yet, goes away entirely with time (wishful thinking, I know).

I just want to have this issue taken care of before I siphon my next batch into one of my kegs. Therefore, I will clean it with PBW, rinse it thoroughly, then sanitize before adding the next batch of beer.

I did not dump the double ipa and tried a sample the other day and the flavor has mellowed. Also I tried one of my bottled double ipas which did not come in contact with the keg and it had the same flavor. Therefore, I have assumed I did a good sanitation job but the ‘off’-flavor I think is actually the simcoe I used in the recipe. Prior to this recipe I had never used this much simcoe or columbus hops in a brew. I think I may just dial back on using simcoe later in the boil. Although it probably did not help that I messed up the hop additions by adding the 15 min addition at 25 min so I decided to add everything else early and cut the 90 min boil short. Lastly, it may have been better for me to bulk age the double ipa longer than I did. Now I just need to learn from these mistakes to improve future batches.


Just to update on my ‘perceived’ keg sanitation issue:

I added a little calcium chloride to a sample of my double ipa and it greatly reduced the harsh taste of bitterness. Also I found out my water is very low in chloride (10ppm) so my gypsum additions made my beer overly bitter. Therefore, I boiled about a pint of water, added the calcium chloride, cooled the water, then added it to the keg of double ipa. The beer is now drinkable and I am glad I did not dump it which allowed me to experiment.

Just wanted to share if this could help another fellow brewer; cheers!