Help diagnose my off-flavor

So I just did my first batch of beer recently after about a year of winemaking, an Irish Red Ale. All in all, it came out really good, but there's a few things I noticed that I think I can do better next time. 1, a few of the last bottles got overcarbonated really fast, and I think this was because when I racked the beer onto the priming sugar, it didn't mix well enough and some of the beer at the bottom had more sugar.

It tastes pretty damn good, but occasionally I notice a slight off-flavor. It's hard to describe. I think it came out a bit overly bitter because I didn't have a hop bag so I just tossed the hops pellets into the wort and so there was a ton of hops just sitting in the bottom of my fermenter. But there's something else. I think it's probably oxidation, but I wouldn't describe the flavor as "cardboard". Maybe a little bit, I dunno.

Oddly, I seem to notice it most when a beer has just been poured, especially if the bubbles make me burp -- I really taste it on the burp, gross as that may sound. But it's only mildly unpleasant insofar as I know it's not a flavor that's supposed to be there.

I've tasted this, or something similar to it, once before. I bought a sixer of a major commercial brewery to remained unnamed's seasonal red ale (probably a coincidence) and it tasted a bit off. After I drank a couple bottles I noticed the "Best by" date was a few months past so I poured the rest down the sink. But I'm unclear how my 6 week old beer could taste like a beer that's too old.

Closest LHBS is about an hour drive in traffic, but I may have to just take a bottle up there and let them taste it unless one of you is relatively confident you know what I'm talking about.

I'm drinking one right now and it tastes great. No hint of the strange flavor. But halfway through, I may notice it on my palate for a few sips. Make any sense at all?

I don't think its oxidation if you had cardboard flavor you would know it.
You mentioned the bubbles, burb, if you got that off the head it could be yeast and I would not consider that a off flavor.

Really hard to describe a small off flavor ain't it?

I can't figure out why oxidation is described as tasting like cardboard. Do people go around eating cardboard? I have no idea what cardboard tastes like.

Just so I can be helpful, here is a list of off-flavors that someone gave me the other day. http://morebeer.com/themes/morewinepro/mmpdfs/mb/off_flavor.pdf

Might show up when it's halfway through due to the beer warming up as flavors are more pronounced at warmer temps. I agree that you might have some yeast character if it is still young. Or even perhaps it might be a character of the hops or grain you used and you are not accustomed to it. Give it some more age. If it is a touch of oxygenation it will get more pronounced. If it is yeast it will dissipate as the beer clears.

Well I think taste can be associated with smell, so if you smell like cardboard then you most likely will taste like cardboard

So I hope most will get the idea of what the cardboard description is about

Lick a piece of cardboard or just smell it...the taste is undeniable

I think maybe I found the culprit from the MoreBeer PDF that LovesIPA posted... DMS... I wouldn't describe the flavor as "Cooked vegetables, especially creamed corn, cabbage, tomato, shellfish/oyster-like flavors" but this line smacked me in the face: "Avoid letting condensation drip back into the wort and never cover your kettle completely during the boil." I kept my kettle covered nearly the entire time I was boiling. I did my boil on the back porch and I was paranoid about airborne contaminants -- I think maybe I wound up doing more damage by putting the lid on so much. I had assumed it was oxidation because I messed up on the bottling bucket racking -- racked half the beer in before I realized I hadn't added the priming sugar, so I had to rack it back into the fermenter, add the sugar, then rack it back again. I did a lot of stupid little first-timer things like that. I suppose all things considered the final product is good. I guess I better get off my ass and try again and make less stupid mistakes this time.

Yeah, you have to boil with the lid off. That will definitely do it.

I put the lid back on after flameout and leave it on during chilling. Some people leave it off the whole time. It's not critical to absolutely guarantee that no bugs get into the wort. Once the yeast start their business they will quickly overwhelm smaller amounts of other bacteria and contaminants.

And just a quick point of fact that many new brewers don't think about: you cannot get an infection during the boil. The boil will kill anything. After boiling (especially below 162*f, which is pasteurization temp), be more careful of infecting the batch.

One thing to consider is that the "wet cardboard" flavor named as oxidation is only when oxidation is very severe.

In less amounts, or in a younger beer, oxidation is usually more of a "sherry" flavor. It's called "madierizing", if you've ever had madieria or sherry. It almost has a brandy finish, for lack of a better description.

If it's oxidation, it'll get worse and not better with time.

DMS is definitely vegetal. If you've ever had Rolling Rock, that beer screams "DMS", for comparison.

freisste said:

And just a quick point of fact that many new brewers don't think about: you cannot get an infection during the boil. The boil will kill anything. After boiling (especially below 162*f, which is pasteurization temp), be more careful of infecting the batch.

Click to expand...

^^ What he said...