Plastic taste in my kegged beer

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

TwoHeadsBrewing

Well-Known Member
Joined
Feb 28, 2008
Messages
3,949
Reaction score
53
Location
Chico, CA
Ok, I was really stoked last Friday to get my first kegging setup. 10# CO2, 2 Cornies, air/beer lines, etc. But now I'm pretty bummed...BOTH of the beers I put into kegs has a plastic taste to it. I can even detect a bit of plastic smell in the beer!!! Not sure if it is an infection, or just new beer lines or what. Any ideas about what is causing this taste?

Just for background:
1) Cornies were cleaned thoroughly, sanitized, o-rings replaced, and there were no odd smells after I was finished.
2) Filled kegs with water/iodophor, let stand for a few minutes.
3) Turned kegs over and let stand for a few minutes.
4) After assembling lines, I flushed them first with the iodophor/water mix, then with water
5) I drained everything and let air dry for 10 minutes or so
6) Racked Blonde Ale into first keg, Stout into second keg
7) Carbonated at 30psi for 2.5 days
8) Backed off pressure to 6psi for serving (6' lines)
 
+1, with one exception.

My Apfelwein has a distinct taste of plastic in the first glass of the evening. after that all is well.

Not to Hyjack, but I suspect the same problem. What ABV is your beer?
 
+1, with one exception.

My Apfelwein has a distinct taste of plastic in the first glass of the evening. after that all is well.

Not to Hyjack, but I suspect the same problem. What ABV is your beer?

Blonde is 5.2%, Stout is 6.4%. I find it odd that both of my beers have this infrection, but none before this batch have. I didn't do anything different to these two batches aside from kegging. Could it be the beer or air lines? I'm using 1/4" thick-walled PVC tubing, it says Foxx Superflex PVC on the side.
 
Maybe a dumb question, but, did it taste like plastic before you kegged? I have brewed a couple of plastic batches that I later attributed to chlorinated tap water in the brewing process. But, both of those tasted and smelled like plastic coming out of the fermenter.
 
Maybe a dumb question, but, did it taste like plastic before you kegged? I have brewed a couple of plastic batches that I later attributed to chlorinated tap water in the brewing process. But, both of those tasted and smelled like plastic coming out of the fermenter.

Nope, both of them tasted great actually.
 
If its your beer lines, I'd think that your first glass of the day would have more plastic flavor than the rest of the glasses since the beer has been sitting in the lines overnight. To test it, I'd let the gas off the keg and pull out a sample with a theif. If that tastes like plastic, then its not your lines...you wouldn't be getting any flavor from your gas lines unless you had black flow into your gas lines resulting from a highly pressurized keg and low regulator setting (Did you bleed pressure off your keg before setting to 6 psi? If not, you could be having back flow into your gas lines & regulator)

Alternatively, did you use anything other than beverage grade o-ring lubricant or mineral oil to lubricate your o-rings? If you did use something else (e.g. silicon), this could be your problem.

It's also possible that whoever had your kegs before you used some cleaning product in them that you didn't get out in your cleaning/sanitizing process, however, based on what you said above, it looks like you were pretty careful when you cleaned them.
 
I was running into this issue as well. You should look up some of Kal's posts on the subject as he did a lot of research into what beer lines to get.

In the end I bought 3/16" LLDPE from Mcmaster. Really cheap and has absolutely no off flavor even with the first two ounces out of the tubing. It is hard to get on the barbs so be fore-warned about that (I heat it up some with a blowtorch before sliding it on a star-san slicked barb). I also make sure to use hose clamps on it to secure it to the barbs. It is more trouble than the vinyl tube, but I like it better and plan to be using it (or slightly larger diameter) when I run cooled beer lines up to the kitchen (It also has a smaller outer diameter than vinyl tube).

Mcmaster part number 5181K42

15 cents a foot, 11 cents a foot if over 100 ft.

Tensile Strength
2,800 psi
For Use With
Air, Beverage, Ethylene Glycol, Food, Water

Likely would be better for me to find compression fittings for this tubing instead barb
 
Question: If I pull a sample out of the keg by opening it up, will this kill my carbonation? I think this is the only way to figure out if the off flavor is related to the lines or something else.
 
You should be just fine opening the keg and taking out a sample, then put the lid back on and put it back up to your normal pressure, not too much Co2 should come out of solution during the brief time you have it open.
 
Ok, disconnected one of the two kegs from the CO2 then purged the air from the keg. Took a sample, and DID NOT detect this same taste! :)

So, I guess this can be narrowed down to the beer lines...right? If that is correct, I suppose I should get some replacement 3/16" ID beer line. Any suggestions? I got this line from my LHBS which has been very good to me, so I assumed it was the right stuff...it says 1/4" Foxx Superflex PVC. Any thoughts?
 
Great news...i've drank five of thes beers tongith...and I can't tell if they have that taste in them! :rockin::drunk:
 
hey weird i just relined my kegerator with the same stuff and have the same plastic flavors. Must be the type of line but good to know it goes away, it is all my local brew shop had at the time.
 
Back
Top