My keg tastes terrible.

OK. I think the verdict is in.

I can't keg any of my light beers because of an unpleasant bitter taste that my kegs are imparting. With darker/hoppier beers, the hops usually mask the flavor enough that you can't really tell unless you're looking for it.

I just put my pale ale in the keg this weekend and it's there, but fortunately there's enough hops in there to salvage the beer.

Carbonating water in a soda bottle using the carb cap imparts no off flavors, so the gas and lines are out. Taking samples out of the top with a turkey baster yields the same off flavors, so the beverage line is out.

The only thing left I can think of is that I'm not cleaning my kegs thoroughly enough. But I'm baffled as to how that can be. Here's my process:

I'm taking everything apart and soaking all the pieces in PBW. This includes pulling the o-rings off the posts and taking out the poppets. The keg gets filled with hot water and then PBW twice for an hour each time, and then I'm siphoning the entire 5 gallons of PBW through the line with the dip tube, which I hold open with some pliers, also twice. Then everything gets sanitized and assembled, and I put a gallon of star san into the keg which I shake around vigorously after sealing everything up, and I push the star san out with CO2. Then I let the foam settle and push the rest out.

Anyone have any ideas? At this point I'm about ready to just give up and go back to bottling.

Does the beer taste OK at the end of fermentation? Could there be an issue somewhere between fermentation vessel and serving keg?

The beer tastes fine post fermentation...

I suppose I could try tasting water that's been racked through my autosiphon.

I'd use a small mirror to take a look around the inside top of the corny keg and make sure that's all clean.

Put a gallon or two of distilled/spring water in the keg after performing your normal cleaning/sanitizing regiment. Let the water sit in the keg for a couple days, then serve some of the water up through your draft lines and taste it. See if the water picks up the same flavors you are getting in the beer.

If the bad taste is from all your kegs then I would look elsewhere - your water perhaps. If it is just one keg, toss it. Unless you really want to spend hours searching, money + a day brewing, 3 -6 weeks waiting to find it happened again....!

From your description it certainly does not seem like you are not cleaning well enough.

stevedasleeve said:

From your description it certainly does not seem like you are not cleaning well enough.

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What would you do differently? I thought I was being pretty damn thorough.

EDIT: Disregard, I misread the double negative.

The thing is, even after all the soaks and stuff the keg still smells like, well, keg.

Maybe you're overcarbing the beer in kegs and getting a real carbonic acid bite. Try pouring a pint and letting it sit in the fridge for 20 minutes. Taste it again.

Bobby_M said:

Maybe you're overcarbing the beer in kegs and getting a real carbonic acid bite. Try pouring a pint and letting it sit in the fridge for 20 minutes. Taste it again.

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Done that already. No dice.

Also, it tastes nothing like the "seltzer" flavor I get when I carb water in soda bottles.

i didnt read anything about using a dip tube brush... you probably have stuff in the keg that simple soaking isnt going to remove. get some brushes and have at it. most of the kegs i buy have dried on soda or other food products inside everything. they will not come off with soaking alone.

I'll try brushing, but I'm just worried about putting nicks and scratches in the aluminum.

And seriously, a 24 hour pbw soak takes absolutely EVERYTHING off my carboays...

I don't even take my kegs apart to clean them (I know, I'm terrible). I just use my water pump that I originally got for wort chilling, hook it up to the keg, shoot hot PBW through it for like 10 minutes, run hot water through it for 5 minutes, run star san through for a few seconds, close 'er up.

Like everyone else said, try putting some spring water in there for a few days and taste it. Also, how often do you clean your lines and faucets? You might be getting off flavors from them.

I'm having the same issue. I just kegged my pumpkin ale last week and the first few days it tasted awesome. And now there is a strong bitter taste that wasn't there in the beginning. I'm gonna try and use a dip tube brush like someone mentioned before. So, now I have to clear out a whole keg of off tasting pumpkin ale. oh well, it'll give me an excuse to brew more.

bernerbrau said:

I'll try brushing, but I'm just worried about putting nicks and scratches in the aluminum.[...]

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What "aluminum"? If these are genuine corney kegs, there's no "aluminum"...

Cheers!

day_trippr said:

What "aluminum"? If these are genuine corney kegs, there's no "aluminum"...

Cheers!

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Is it stainless? Well, still, metal scratches...

Not a wire brush, just a round nylon one.

turkeyjerky214 said:

I don't even take my kegs apart to clean them (I know, I'm terrible).

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this is probably fine for reusing your kegs from batch to batch, but the used kegs that i get at the LHBS for $30 usually require some powerful elbow grease to get all of the dried on crap off that has been sitting in them for years.

remember premix soda has been phased out many years ago, some of these kegs were just put into storage as they came back from the customers. many still have years-old soda in them. also if you have never replaced the soft parts (orings; $3 per set), its $3 well spent. you dont have to do it often, but you should do it once when you initially get them. the soda taste will often never come out of these parts.

i do a complete tear down right when i buy a keg. replace all soft parts. run caustic thru the entire thing if its very dirty. soak the dip tubes, poppets, and lid seperately (the lid is normally aluminum, so you cant use caustic on it). soak in your choice of oxiclean/pbw/hydrogen peroxide for a few minutes or hours, then scrub everything well. then one last rinse, reassemble and lube all the soft parts, and then finish with starsan.

if i am just refilling the keg, all i do is rinse it out with some hot water, run a few cups of starsan thru everything, and then refill.

What caustic do you use for newly bought kegs?

...

I use OXY Free with real hot water when I get the kegs. Between fill ups I just dont soak as long. I love oxy free because I can tell when it is all rinsed clear by the squeaky clean feeling. If not clear you still have that slight slimy feel.

audger said:

this is probably fine for reusing your kegs from batch to batch, but the used kegs that i get at the LHBS for $30 usually require some powerful elbow grease to get all of the dried on crap off that has been sitting in them for years.

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I agree. My first 5 were from keg connection, and the other 12 I got were from a fellow homebrewer. The ones from KC, I cleaned a little better, but the ones from the homebrewer were immaculate. Cleaned, starsan-ed, and pressurized.

I'm thinking that I might start keeping track and every 5 uses take the kegs apart completely, but for now my method seems to be working well.

I may have figured something out.

Does PBW require rinsing?

bernerbrau said:

I may have figured something out.

Does PBW require rinsing?

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Yes. With as warm or warmer water than whatever temp the PBW solution was at. That would be an easy fix if it were your problem!

Welp, the next step is to soak a glass in pbw, dump it, fill with water and taste.

bernerbrau said:

Welp, the next step is to soak a glass in pbw, dump it, fill with water and taste.

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That could well be it! Keep us posted. That said, there's nothing wrong with another good caustic soak and a hard scrubbing if you haven't done that yet.

Good luck!

Tried it, and while I did discover the source for a different off flavor that I had previously attributed to the dishwasher on my beer glasses, it's not the same awful bitterness...

I guess I could mimic my cleaning regimen in my stainless brew kettle - PBW 30 minutes, dump, star san 1 minute, dump, add light commercial beer from bottle, wait 1 hour, taste. That would rule out any interaction between PBW and stainless.

Of course the problem could just be my keg needs a good scrub.

After you use pbw, you need to rinse with hot water a couple times. Pbw seems to leave a slippery residue and seems to need a rinse after. Then do the starsan

JRems said:

After you use pbw, you need to rinse with hot water a couple times. Pbw seems to leave a slippery residue and seems to need a rinse after. Then do the starsan

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Right. The point here is to try and mimic the conditions of the keg to see if that replicates the off-ness in my beer, so no rinse.

This weekend I kegged 2 lagers that I brewed late last year. One of them, in the same keg as before, picked up the same undrinkable funk after 24 hours.

This time I had replaced my siphon and hoses, taken everything apart, thoroughly soaked the kegs and all the pieces in double strength oxyclean, scrubbed everything inside and out, including the dip tubes, posts, poppets and disconnects; triple rinsed, twice in cold water and once in scalding water, then sanitized, sealed everything up, and used the gas to push star san through the lines until the kegs were both empty.

So, I've got an acquaintance who performs a certain "conversion service" with beer and wine; I'll fill up some growlers and drop the bad beer off with him, bleach bomb the keg, then replace all the o-rings and the beer lines.

If this doesn't work, I'm tossing the keg.

So it is just this one keg...? Very strange, I am really curious as to what the issue might be.

H-ost said:

So it is just this one keg...? Very strange, I am really curious as to what the issue might be.

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I'm not 100% sure if it's restricted to this one keg or not because I don't keep good enough notes... but having the issue pop up twice in the same keg is arousing my suspicions. I'm thinking I had a light lager develop this taste in the same keg early last year.

I've read several comments on bitter and starsan. When you say a gallon, you mean you mixed starsan with a gallon of distilled water?

Old_mil_guy said:

I've read several comments on bitter and starsan. When you say a gallon, you mean you mixed starsan with a gallon of distilled water?

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Tap water, but yes. A gallon of concentrated starsan per keg would be a bit spensive.

The hell with it, I'll give that a try and see if a drop of starsan funkifies some beer.

Subscribed. I just bought my first keg and the beer smells funky but actually doesnt taste near as bad as it smells.

bernerbrau said:

Tap water, but yes. A gallon of concentrated starsan per keg would be a bit spensive.

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I thought so but just trying not to overlook anything.
No idea if there's any benefit but I'm using starsan and rinsing again with boiled water.

I never rinse out my kegs after I use starsan, and I use it within seconds of putting the beer into the keg. I have never had off flavors from starsan so I wouldn't think thats your problem.

I may have missed it, but have you tried to take a sample from the top of your keg? And I do mean to take the lid off, and remove a sample. If that tastes fine, your at least focus it down to the outlet of the keg.

Chad_C said:

I never rinse out my kegs after I use starsan, and I use it within seconds of putting the beer into the keg. I have never had off flavors from starsan so I wouldn't think thats your problem.

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What if my dip tube's too short in that keg and there was a pool of it in the bottom? It's a longshot but can't hurt to rule it out.

Hmmm... You did say you pumped it out, I forgot about that. I just pump a little bit out, then tip it upside down to get rid of it.

Did you catch my second part? I edited it to add.

Yep, been there, done that. No difference. Up to this point I have tried everything under the sun except bleach bomb it and replace all the non-metal parts.

Did you try the distilled water in the keg test?