Beer turned sour 1 week in keg

I believe it's the first time I have used the keg (I have 4, can only hook up 2 at a time) but a beer I put in a week ago is now sour. I sanitized the keg twice, once when I bought it bought it an put new rings on and just before racking my beer with StarSan.

The beer is a double simcoe ipa, the day after I kegged under 30psi I was drinking it and I had no trouble with it (excellent IMO). 1 week later, it's noticeably sour. Reminds me of grapefruit skin left out in the trash for a day. It's not exactly undrinkable but it's not that pleasant either.

Even if it's not infected I'd like to clean everything properly with bleach and replace what I can't. I didn't notice the sourness until 1 week so think if it's an infection it came from the keg. I fermented in a plastic 6 gal bucket, should I replace it? What about the seals on the keg, replace those too? All the plastic lines to and from the keg? Appreciate any advice.

Thanks -

If the beer was fine coming out of the fermenter, I dont think you need to replace that.

It wouldnt be a bad thing to replace all your o-rings and the beer line. If there is an infection, they could be the source of it and they arent expensive either.

Also, if its the first time you are using the keg, there may have been some soday syrup or caustic left over from cleaning, etc. I gave my news kegs an few hour soak with Oxyclean and then rinsed a few times, and then sanitized.

Replace what you can and then clean and sanitize like crazy. Hopefully that'll fix it for you

did you purge the keg?

It's not clear from your post, but did you replace all of the O-rings & seals initially when you got the keg? I always do as standard practice, it's cheap insurance. Avoid using bleach on the keg or other stainless steel items as it can pit the metal. I would completely disassemble the keg and clean it well. The easiest way is with PBW, automatic dishwasher detergent, Oxyclean or similar strong cleaning products. Let it soak overnight or even longer and do the same with all of the fittings, poppets etc. Get a dip tube brush and use it. I disassemble my kegs after every use. The exception may be if I am racking from keg to keg and there were no problems with the receiving keg. In that case, a quick Star San rinse is all I do. Drain and rinse everything very well. Use Star San on all the fittings and O-rings before reassembly. This may sound like a lot of work and a big hassle, but it's really not. Have the right tools (deep sockets etc) available and it's quick. You also gain speed after you do them a few times. I only rarely find it necessary to scrub the inside of my kegs. They rinse squeaky clean after the long soak in hot detergent.

I would replace all of your transfer hoses as a precaution. You also want to clean and keep clean the keg quick connects for both the beer and the gas. The gas connector is often overlooked and it can and will get dirty through use. Anything on it or in the gas line will get blown directly into your precious beer. The connectors can be disassembled easily. The gas line is another often overlooked suspect and the regulator too. Beer can back up the gas line under certain circumstances and eventually it will cause problems.

The plastic fermenter could be the source, even if the beer seemed OK initially. There's a chance that the critters had not yet become numerous enough to be noticed. They multiply exponentially on one of them J curves IIRC. To us, it sometimes seems they appear overnight. I would nuke the fermenter the same way as the kegs. Give em all you got. This is war!

Thanks for the feedback. I had replaced all the rings and sanitized last Dec or Jan when I bought it but didn't using anything besides StarSan at the time. I always disassemble the kegs when sanitizing but not always the connects, I'll tear those apart too and clean them.

I didn't realize I couldn't use bleach on SS, glad to have this warning!

Yes, it's a drag to discover bleach pitting on SS after the fact. I ruined a SS stove top that way long ago.

Star San is a surface sanitizer only and not a cleaning agent. You should not try to sanitize something that hasn't been properly cleaned beforehand. It may or may not be enough and it's generally not worth taking the risk.

It's also good practice to always clean and sanitize kegs asap when they are emptied. Rinse and sanitize again before next use. That last step may be overkill, but it only takes a few minutes so it's not much of an inconvenience.

Kegs can take bleach solution just not for extended times.

Catt22 hit the nail on the head though imo...you must clean it first. Starsan is just a sanitizer and the surface must be totally clean and well rinsed for it to work.

I've actually been known to disassemble a keg and boil all the posts, o-rings, gas dip tube. Sometimes they get some corrosion that I can't get off so I take it over-the-top.

A nice long soak in oxyclean should do the trick to clean the keg, and then rinse very well. 3 times with hot water at least. Disassemble the post and soak everything broken down including the tubing overnight. Then sanitize, fill it with some water and charge with Co2 and purge the air. If the water taste OK after two weeks you should be good to go.

Great advice, thanks everyone.

Degas a sample of your kegged beer and see if it still taste sour. You might have it carbonated too high for your taste. Carbonic bite can make a beer a bit harsh.

Take the posts off and check the poppits. The springs trap debris.

I don't think it's necessary to take the poppets out as some have suggested -they can be difficult to get back in depending on manufacturer.

I usually just fill one keg with PBW (one that has already been thoroughly cleaned without taking the posts off and poppets out) and push it using pressure from one keg via the line-out to the line-in and then line-out to the line-out of the other keg. Most of the time I repeat this several times back and forth - you only need a little bit of gas. you could probably use a pump instead of CO2.

I do a clean rinse using hot water, repeat, and then use sanitizer.

I collected my yeast from this batch. I didn't notice any sourness until a week after in the keg (burst carb at 30psi but I get no excessive foam when pouring back at 12psi, in fact it seems under-carbed) but wonder if I should also dump the yeast, "just to be safe"?

I don't think it's necessary to take the poppets out as some have suggested -they can be difficult to get back in depending on manufacturer.

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Here's a couple of things I do that makes the poppets so incredibly easy to remove/install that I always remove them as a matter of course:

If it's a type of keg where you need the poppet to stay up inside the post when you thread it on then I use the barbed portion of a 1/4" tee nut like this to lightly tap the poppet in. The hollow center allows you to tap the 'legs' of the poppet without tapping the center shaft.

If it's a Cornelius keg or any keg where the poppets just fall out of the post when removed, then I carefully place the poppet on top of the dip tube and then stick a chopstick through the hole in the post to sort of hold the tip of the poppet while I thread the post on.

Chopsticks are nice tools to have around and work great to depress keg poppets.

A quick followup in case anyone cares. The beer is still on tap, too lazy to disconnect and don't have anything else to put on it. The sourness has not increased, it's the same. I'm wondering if the sourness might be a by-product of the whole leaf dry hopping (in primary, not in the keg).

I took a 'sample' and let it sit overnight getting all the CO2 out. The FG is exactly the same, 1.020. If this was an infection, would I definitely have seen the gravity drop?

More than likely, yes. The gravity should continue to drop, but it may do so very, very slowly if you are keeping the beer cold. The sourness should also increase as the bacteria produce more byproducts. Regarding the nature of the sourness, I would have some of my fellow homebrewers taste it and get their opinion.

Catt22 said:

More than likely, yes. The gravity should continue to drop, but it may do so very, very slowly if you are keeping the beer cold. The sourness should also increase as the bacteria produce more byproducts. Regarding the nature of the sourness, I would have some of my fellow homebrewers taste it and get their opinion.

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This is your 911(st) post so it sounds like you just volunteered to come rescue my beer. I'll shoot you my address in a PM, hope you don't live too far from Atlanta. As a consolation, I have more beer - non-infected - on tap and in the bottle for when you arrive .

Took a sample to Ed (BMW) and he said it's not infected, just the Simcoe giving it the sourness. I'm going to let it sit for about 6 more weeks and try a sample then. I'm gonna try this recipe again, just let it age much longer.

Just an FYI - I have had friends claim to get infections from dirty beer lines. An occasional cleaning out the line with BLC or starsan is a good idea.

I'm convinced that many infections are due to lack of cleaning and sanitizing the gas line ball lock connectors. I mentioned it in an earlier post, but it's worth saying again. Any contaminants in the gas connector will get blasted directly into the beer when you force carb or charge the keg for dispensing. Beer can easily back up into the connector and gas line under certain circumstances and if these are not kept clean and sanitized, it can spell trouble. The ball lock connectors can be easily disassembled for cleaning. I think these are often overlooked, particularly the gas connector as they aren't normally supposed to have any beer in them as the beer out connectors regularly do.

Dirty beer lines can make the served beer taste horrible. I've been to bars that served well known craft beer through dirty beer lines and it was undrinkable. I know what those particular beers should taste like and something was definitely wrong and I can only think that it was the lines and/or taps.

Catt22 said:

I'm convinced that many infections are due to lack of cleaning and sanitizing the gas line ball lock connectors. I mentioned it in an earlier post, but it's worth saying again. Any contaminants in the gas connector will get blasted directly into the beer when you force carb or charge the keg for dispensing. Beer can easily back up into the connector and gas line under certain circumstances and if these are not kept clean and sanitized, it can spell trouble. The ball lock connectors can be easily disassembled for cleaning. I think these are often overlooked, particularly the gas connector as they aren't normally supposed to have any beer in them as the beer out connectors regularly do.

Dirty beer lines can make the served beer taste horrible. I've been to bars that served well known craft beer through dirty beer lines and it was undrinkable. I know what those particular beers should taste like and something was definitely wrong and I can only think that it was the lines and/or taps.

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Thanks for the gas line tip! Never thought of that.

There's a few local places that have micros but they taste like crap. Lines are either dirty or the beer is old. I was watching preseason football, had a fat tire on tap. It was bad. I wound up drinking Bud Ale since there was anything but the ordinary swill. A long time ago I stopped drinking Newcastles there. There were putrid.