another kegging off flavor question

[Porkbuttsandtaters]

I read the post from bradleypariah about the changing of flavor in his beer after kegging and though I got some good info from it, I didn't find exactly what I was looking for. So please help if you can.

I all grain brew and I do not treat my water. I have only been brewing a couple of years but I have brewed across the spectrum from a Berliner to a 10% Imperial pumpkin (don't judge, SWMBO like them).

I just made the jump from bottling to kegging about a year ago and that is when things started going down hill with the flavors.

I do not transfer to secondary (never have) so after fermentation I transfer to my corney keg, put it in my keezer, and start the carbonation. I usually set my regulator to about 25 psi for the first 24-30 hours then I drop it to 10-12 psi (depending on the beer style) and let it sit for a few days before I even try to drink it. My keezer is set at 41 deg F for what I figured is a middle of the road temperature for multiple beer styles.

During the transfer to the keg my beers taste good, once kegged and carbonated it's a different story. My darker beers continue to taste fine (I currently have a chai milk stout and a tart cherry wit that were brewed, kegged, and carb'd all at the same time). My tart cherry wit has no cherry flavor, no nose, and tastes almost nothing like beer; it has been kegged and carb'd for about a month now. The Berliner I brewed was the same way.

Here is where it gets difficult, I know. I can't describe the bad flavor or aroma. I don't know if it is band-aid, horse blanket, carb-bite, yeastie, metallic, etc. etc. I don't know what the characteristics off those off flavors are, I just know it taste bad and overpowers the beer.

Thank you all in advance for any input.

 

[Brulosopher]

I'd reckon many will posit yours is an issue of oxidation, and while that may play a role, I'm not convinced... just yet. That said, perhaps you can try purging your keg (push starsan out with gas before filling) to see if that helps.

Or, if you're feeling up for it, send a bottle to me to be reviewed on the 1 Minute Beer Review with Jersey & Tim (from The Brülosophy Podcast). I'll give you some feedback too [emoji482]

 

[doug293cz]

It may not be oxidation, but it could be. Lighter beers are less tolerant of oxygen that darker beers. What is your process for racking from the fermenter to kegs? Please provide as much detail as possible, up to the point where you set to 25 psi.

Brew on

 

[Porkbuttsandtaters]

My transfer process is simple, and probably archaic compared to others out there, but it's all I know.

Thanks for the replies, here is the requested info.

I ferment in food grade buckets. Once fermentation is complete I put the bucket of beer on a table and place the keg on the floor below it. I use a simple plastic racking cane from my LHBS and a length of clear tubing; a couple of pumps of the cane and the beer starts flowing. I leave it alone until almost all of the beer is out of the bucket, I stop it before any of the sediment in the bottom of the bucket starts to get sucked up.

The length of tubing from the cane to the keg is long enough that it touches the bottom of the keg so the beer is not falling into the keg, splashing, and aerating (at least that is what I have been thinking).

From there I seal the keg, carry it downstairs, put it in the keezer and put it on gas.

Thanks again!

 

[geoffm33]

From there I seal the keg, carry it downstairs, put it in the keezer and put it on gas.

When you hook it up to the gas, do you purge the headspace from the keg using the pressure relief valve? I give it a few 3 second burps once it's on CO2.

 

[Porkbuttsandtaters]

When you hook it up to the gas, do you purge the headspace from the keg using the pressure relief valve?

No, I have not been purging the headspace. Thanks for the tip, I will from now on. Would that alone result in the off flavor in my lighter beers while not affecting the darker ones?

 

[mongoose33]

Here are a few thoughts. You said this began when you started kegging. What process did you use to clean the kegs, and/or what process do you use to clean them between fills? Were they new kegs that were not cleaned? Old kegs with off-flavors as part of them?

Old soda kegs with some crusted on flavor syrup still inside?

What's the source of your CO2? Normally I wouldn't expect that to cause off-flavors, but....

Are you sure your racking cane and tubing is clean and sanitized?

Just a few thoughts....

 

[geoffm33]

No, I have not been purging the headspace. Thanks for the tip, I will from now on. Would that alone result in the off flavor in my lighter beers while not affecting the darker ones?

It could contribute to oxidation. Not sure I've seen anything definitive, but it's probably a good idea to purge the oxygen from the keg before carbonating.

Like many things in homebrewing, lighter beers are harder to hide off flavors.

 

[Porkbuttsandtaters]

What process did you use to clean the kegs, and/or what process do you use to clean them between fills? Were they new kegs that were not cleaned? Old kegs with off-flavors as part of them?

Old soda kegs with some crusted on flavor syrup still inside?

What's the source of your CO2? Normally I wouldn't expect that to cause off-flavors, but....

Are you sure your racking cane and tubing is clean and sanitized?

A couple of kegs I have are from a mail order homebrew supply and a few others I bought from a local brewery. I disassembled them and cleaned them with Starsan before use.

My CO2 is from a local distributor who supplies many of the local breweries.

I clean my racking cane before & after each use and sanitize it before racking. I do the same for the tubing and replace it every so often.

 

[mongoose33]

A couple of kegs I have are from a mail order homebrew supply and a few others I bought from a local brewery. I disassembled them and cleaned them with Starsan before use.

My CO2 is from a local distributor who supplies many of the local breweries.

I clean my racking cane before & after each use and sanitize it before racking. I do the same for the tubing and replace it every so often.

Star-san isn't a cleaner, it's a sanitizer. It won't necessarily remove oils or other flavors. You need something like PBW to do that.

Oxidation is a possibility but I was discounting that since apparently the beers had the off-taste immediately.

When I clean kegs for the first time, I soak them in PBW or put them on my keg washer that uses PBW solution. I pull the posts and poppets and soak them in PBW too. Then I rinse in water until I'm sure they're clear of PBW, then rinse again in Star-San.

I presume you're using keg-lube on the seals and not something like vaseline?

What you might also try next time you're racking to a keg is clean that thing to within an inch of its life. Reassemble, use keg lube on the seals, then when you're racking to the keg, also fill a few bottles and use carb drops (fizz drops, whatever they're called) and let those beers naturally carbonate. That will give you a baseline against which to compare the beer and it cuts all the kegging stuff out of the loop.

 

[BlkWater_brewer]

A couple of kegs I have are from a mail order homebrew supply and a few others I bought from a local brewery. I disassembled them and cleaned them with Starsan before use.

My CO2 is from a local distributor who supplies many of the local breweries.

I clean my racking cane before & after each use and sanitize it before racking. I do the same for the tubing and replace it every so often.

Right off the bat your problem could very well be from dirty kegs. Starsan is not a cleaner. It is a sanitizer and will not clean any build up or crud. There is a difference. I would use something like PBW first. PBW has to be hot to clean, then rinse with hot water, then starsan. Oxidation could still be part of the issue, but I would bet on cleaning.

 

[Porkbuttsandtaters]

I apologize, I was not very clear in my post. I cleaned the kegs then used the Starsan before kegging. Sorry about the confusion.

 

[IslandLizard]

I apologize, I was not very clear in my post. I cleaned the kegs then used the Starsan before kegging. Sorry about the confusion.

Did you take the kegs apart, soaking and scrubbing all parts and surfaces with a suitable cleaner? Brush the insides of the dip tubes? What did you use as cleaner?

I once forgot to purge the headspace of a newly filled keg of wheat beer before force carbing it (rolling at 30 psi for 5-10 minutes). The beer was fine for the first few days, but the older it got the more flavors became muddled and stale. It also darkened quite a bit. Added a good pour of orange juice to a glass made it more palatable, but never good.

 

[Weezy]

Sounds like oxidation to me. Flabby, lifeless beers. With time you'll get cardboard taste out of pale blue and soy sauce out of dark beers.

As was said,
Clean kegs well with warm water and pbw. Remove hardware and clean separately. Rinse well.

If not immediately filling, I give them a squirt of starsan from a spray bottle. Over and air dry before reassembly.

Before kegging your beer, fill keg with starsan solution, seal and evacuate with co2. Once empty, open and gently dump remainder. Fill keg as you are but under the blanket of co2. Once filled with beer, seal and hookup to co2. Purge half a dozen times by pulling pressure release valve after each time you hear the keg fill with co2.

 

[Porkbuttsandtaters]

I think I am good on the cleaning of the kegs aspect. I was thorough with the disassembly and cleaning and the sterilizing with the Starsan.

I definitely have been lacking with the use of CO2 during transfer from the bucket to the keg and in purging the headspace after filling the kegs.

The feedback and suggestions have been greatly appreciated, thank you all.

Anything else I should be aware of that can be a source or a contributing factor for this particular flavor issue besides what has already been discussed?

And, is there any way to save the beloved beer I already have kegged? The tart cherry wit was really good at the beginning.

 

[mongoose33]

If you have an extra keg, you can do this very well.

1. Fill extra keg with star san. Just about to the brim. Affix lid. Add gas, purge 10 times or more.

2. Using a jumper from OUT post to OUT post, connect to receiving keg. Add a little gas to the donor keg, and push the Star-San from the first keg to the second. When you fill the second keg, gas will start bubbling up from the bottom of the OUT diptube, creating foam. Let it happen, connecting/disconnecting as need be to create it.

Know what's in the bubbles? CO2! Insert the lid inside the keg, add a little more gas, let the foam fill the underside of the lid. Then, in the foam, affix the lid. You now have a keg full of Star-San plus CO2, and it's purged.

3. The original keg is pretty good; still has a little star-san in it. I use a piece of silicone tubing from the OUT QD to the spigot on my fermenter. Before I connect, I blow out whatever remaining Star-San there is into a sink. By that time, I have a very nearly perfect keg of CO2 and nothing else.

4. Then, I pull the PRV to release pressure, at least most of it. Then I connect a line from the IN post and let the remaining CO2 blow out the air from in the tube. I disconnect and immediately connect the tubing to the top of the fermenter (I use a cutoff airlock, but tubing from a plastic bottle filler works too, and that's what I use now).

So my return gas line is almost pure CO2. Inside the fermenter is almost pure CO2 (i use a gas collection device to return CO2 into the fermenter when I cold crash it).

5. I run just a little out of the spigot to clear the small trub layer.

6. I attach the filling line to the OUT QD and let the gas clear that too, blowing into the end of the spigot. Yeah, I know it's anal, but you might appreciate the flavor of the beers I do.

7. I then connect the OUT line to the fermenter and open the spigot. As the beer fills the keg the displaced CO2 goes out the IN post and back into the fermenter. No outside oxygen-laden air coming into the fermenter, and no O2 is in the receiving keg.

Here's a pic, it's worth a thousand words, plus a pic of the jumper. You can buy it from Morebeer or, as I did, make your own.

I know the above looks complicated but once you figure it out, it's really not. I just do it as a matter of course, as I want as little O2 coming into contact w/ my beer as possible.

You might try something like this, see if it helps. And if you're using a bucket, you can use a sterile siphon (clear it w/ CO2 first, and cut a second hole in the bucket lid through which you can pass that, using a stopper to close it when fermenting.

 

[Brulosopher]

It may not be oxidation, but it could be. Lighter beers are less tolerant of oxygen that darker beers. What is your process for racking from the fermenter to kegs? Please provide as much detail as possible, up to the point where you set to 25 psi.



Brew on

I use Brew Buckets mostly these days, but the process is the same regardless. At the end of my tubing that's going from the fermenter to the keg, I attach a liquid disconnect. That liquid disconnect gets attached to the liquid post on a closed keg, and since I use pin lock kegs, I attach a plastic depressor to the gas out post on the keg. Then I open the valve on the Brew Bucket, or start the siphon on my carboy using a sterile siphon starter, and fill the keg with beer. It's really easy and keeps flies out of the keg.

 

[harry_the_face]

I would propose two things to you:
1. First I think there is a distinct difference in the flavor of beer that is force carbed versus bottle conditioned. When I first started kegging I force carbed and didn't like what it did to my beer so I went back to adding carbing sugar to the keg and letting it sit for a week or so. That might be the difference you are experiencing. Try naturally carbinated and see if it changes.
2. How often and how do you clean your beer lines? I didn't clean my lines much and noticed that over time my beer had a funky flavor. I finally made a beer line cleaning system ad ran oxyclean free through it for 5 minutes per line followed by rinse water and my beer was miraculously better. I would recommend cleaning your lines between each keg.

 

[doug293cz]

No, I have not been purging the headspace. Thanks for the tip, I will from now on. Would that alone result in the off flavor in my lighter beers while not affecting the darker ones?

Purging the headspace is critical. If you don't purge the headspace, your CO2 absolute/partial pressure is 14.7 psi lower than you think it is. If the headspace is 100% CO2, then 10 psi gauge is actually 24.7 psi absolute CO2 pressure (the CO2 partial pressure.) Carbonation charts and calculators all assume that the headspace is 100% CO2 with no air.

Also, the O2 remaining in unpurged headspace will oxidize the beer over time. Depending on the style of beer and O2 concentration, flavor degradation can occur in a matter of days. Commercial brewers target total packaged oxygen at 100 - 200 ppb (0.1 - 0.2 ppm). Air is 210,000 ppm. Here's a table and chart that shows how headspace O2 content varies with the number of pressurize-vent cycles for various CO2 pressures.





You can reduce O2 exposure even more by pre-purging the keg with CO2 (liquid fill with CO2 push out is most efficient), and doing closed transfer from the fermenter to the keg, as described by previous posters.

Brew on

 

[Porkbuttsandtaters]

Sorry for the disconnect from this post, I was away at Army drill all weekend. Anyways, wow, so much good, new information, pushed my way, thank you all!

Mongoose33 - that is a lot of information and steps to digest, but I am definitely going to give it a try. What have I got to lose at this point?

Brulosopher - I like that idea for a smoother transfer of the beer to the keg. I think I even have an extra liquid end connector in my box o' brewing stuff.

harry_the_face - I am currently just using tubing and picnic taps until I figure out how I want to set up actual taps. So I keep my keg lines and picnic taps coiled up inside the keezer with the kegs. To answer your question, I clean my taps and lines after each keg (they last about 3-4 weeks).

doug293cz - I definitely learned from the responses to this post that purging the headspace is important, nay, critical; your input and charts drive that home at an even higher level. And I had no idea about the psi difference on the guage with the O2 in the keg! The PPM info is an eye opener too.