Carbonic Acid or Bad CO2

[vincanis]

Hello everyone,

I've recently switched over to kegging and I've been having some off flavors. I used to bottle and never really had any problems but I've gone through two batches that have had the same off taste. Originally I thought my first batch got infected but the most recent one also has the same off flavor.

I'm fairly certain that it has something to do with my CO2 and I'm not sure whether it's too much CO2 or bad CO2. The only way I can really describe the taste is Cider-y. The first batch was a fest beer and the last one I did was a Hefe. Everything smelled and tasted great until kegging and I'm sure I disassembled everything and sanitized. With the Hefe I pretty much soaked everything in StarSan for at least an hour and used aluminum foil sprayed with StarSan to cover any openings while transferring to kegs.

I have tried carbonating water and it has the same taste but I still can't determine whether it's Carbonic Acid or bad CO2. One other thing to note is that I am using 2.5 gal kegs and not a 5 gal.


I believe with the first batch I went to 20 psi to force carb, and then 10 psi to serve. On the hefe I pressurized to 15PSI to get a seal set and then reduced to 3 or 4 psi immediately and let it carb slowly and serve.

Anyone have an opinion on what it may be?

 

[Build]

Is your regulator, tank, lines, etc new? I have a co2 tank/regulator from the 1920s that had a funny taste when I first started using it, but it went away after some use. Is the taste a little metallic bronze? Taste like a penny?

 

[vincanis]

Everything was bought brand new. Regulator, lines, kegs, even the CO2 tank.

I guess it does kind of taste metallic. I'm very bad at describing tastes, which isn't helpful. It's not bitter like mineral water, but it's sort of "sharp" and "biting." Maybe a bit metallic

 

[cannman]

Have you brewed these exact recipes before? It's hard to say it's the co2 over your process until you can repeat reliably.

Metallic often is over carbonation... But just in case it's not, let me recommend something I did when I too thought it was my co2.

https://www.morebeer.com/products/morebeer-ball-lock-keg-rinser.html

Hook a setup like that to a pump with hot PBW, let it run for 10 minutes and then hit rinse.

Another thing to do is open up the keg quick disconnects and wash/scrub the spring gasket etc from gunk from hop leaves yeast etc.

There is also a co2 filter on the market... There are mixed reviews regarding if it's necessary though...

 

[Horseshoot]

Another thought: Green beer. When I started kegging, I noticed that I started drinking the beer much sooner than I did when bottling. Simply because it was carbonated sooner. I, too, had "cidery" off flavors. Now, I determine (from experience) how long a certain beer should sit in the keg, before I drink it. Early on, this was from having a REALLY good glass of brew, just as I was kicking the keg! And I thought to myself, wouldn't it have been nice if every glass had tasted like this? If I brew a new recipe, I now simply pour a tiny sample, every few days until it tastes right. THEN I start serving it.

Hope this helps!

Mike

 

[kev211]

Ya I agree with horseshoot. Sounds like green beer to me. What was your turnaround time from grain to glass in both cases? It could be carbonic acid, but i doubt it. The only time Ive ever detected carbonic acid in my beer was when I force carbed at 30+ psi. I usually carb at 16-20 psi and never taste carbonic acid. But I do notice that my beers taste cidery when Im impatient and pull a pint off too soon.

 

[vincanis]

I thought it may have not been sitting long enough. I haven't tried it in the past week or two. I think I had fermented for about 6-8 weeks and then a week carbonating or so.

The odd part to me is that it was the exact same taste in both of the beers. I'm going to try buying another hefe recipe, make it and then bottle half and keg half to see what's up.

Has anyone here been using 2.5 gal kegs? I figured the first time it was because I had too much CO2 at 10 PSI due to the volume difference but I don't know if that actually matters, so I cut it down.

I'm going to look into the pump with PBW. To clean the keg before the next batch.