Who is brewing, right now?

[NateBrews]

Oh, I'll bring my LHBS guys something good too. I hate bringing something terrible to inflict upon them. The Brunch Milk Porter I made came out delightful.

Also, I just went back and rechecked the gravity on it. Still 1.008, which means it has been stable since 8/21. I suspect it isn't infected with anything that is chewing on the residual sugars.

[Kbar]

Last two batches were Decoction mashes. Oktoberfest then a Helles. Makes for a long brew day.

[Bugeater]

How are you doing the mango? puree at the end of the ferment?

I'm adding frozen mango chunks to secondary.

[brewinhard]

Oh, I'll bring my LHBS guys something good too. I hate bringing something terrible to inflict upon them. The Brunch Milk Porter I made came out delightful.

Also, I just went back and rechecked the gravity on it. Still 1.008, which means it has been stable since 8/21. I suspect it isn't infected with anything that is chewing on the residual sugars.

Nate,

In my experience with wild yeast infections, when the beer is kept cold it pretty much arrests their ability to continue to ferment the beer. Rather, they impart their off-flavors and that is all that really tends to occur. My kolsch with the same yeast you used (WY 2565) is still pretty hazy (from powdery yeast) even with gel fining and 3-4 wks in the keg. That is just how that strain is. With that being said, the yeast does not impart any phenolic off-flavors that I detect. Wild yeast are a strange group of organisms. I don't think adding any fresh yeast will make any difference and you will just be wasting your time and money. Give it another 1-2 weeks in the keg, have a taste and see how it is. If the phenolics are still there or have increased, dump it. Clean your keg well before next use and you should be good to go.

Have you brewed another batch since then that came out clean?

EDIT- This past spring I picked up a wild yeast infection in one of my comp bottles of Helles that I beergunned for a comp. The keg was great and went on to take a BOS at a second comp a week later so I know I picked it up in the bottling process. The funky entry had a slight plastic finish to it that my buddy and i both picked up on at the comp beer banquet after judging. Can't win em all I guess!

[NateBrews]

The gravity of it was stable for 2 weeks at 70F, I'm not sure if that would have been long enough to give whatever might be in there a chance to make a change. After kegging it up, I stripped the yeast with gelatin and most all of it is out now. I tasted it again yesterday and I thought "am I just missing something obvious, I kinda get green apple jolly rancher from it this time". I'm not sure why I wouldn't have picked it up as that before, but whatever. If that is the case then it may well be some fermentation biproducts that were left behind. Also, the flavor was somewhat less intense this time when I tried it vs last week.

I have done 2 batches since then (porter and a pale ale) that both are fine. I didn't use that fermentor for either of those though. The fermentors I have are old glass carboys, and at least one of them I don't use because it has some deposits on it that I can't get off so I can't effectively clean/sanitize it. I've been considering just chucking it and getting a big mouth bubbler to replace it (plastic this time).

Given that, I went ahead with my krausened yeast experiment. I didn't have to get any new yeast, I just pulled some from the pale ale yeast cake and woke it up with 500mL of wort. If I understand what is going on correctly, then the strain that is used to scrub it shouldn't make a ton of difference so long as it is pretty neutral. The best case is that it cleans it up, worst case is that I'm out 500mL of wort and a little time. Figure it is worth it just for the learning.

[brewinhard]

At that stage in the game, I can't imagine a neutral yeast would impart any flavors at all. Keep us posted with the results. Almost sounds like the beer just needed to condition a bit more to clean up. Have you used WY 2565 before? It does tend to impart an almost white whine (chardonnay-like) grapiness to the beer when it is young. Maybe that is what you are picking up on?

[NateBrews]

This is my first time using that yeast. I think you might be right on with that chardonnay thing, I wouldn't have put that flavor together with it but now that I am reading it I think that describes it well.

I'll give this a few days and then strip the yeast out and chill/carb it up and see what I get. I took a quick taste of it after 24hr or so and the flavor is notably reduced.

[NateBrews]

So I pulled another sample tonight and tried it. Just smells like mandarine oranges now (presumably from the mandarina bavaria hops). I couldn't pick up any of the off flavor I was getting before. I do get a bit of yeast in it suspension still, but a little gelatin and cold will fix that. Signs look good for an 11th hour recovery.

As a note about the hops, the orange aroma is pretty intense and I only tossed in 1oz at flameout and 1oz dryhop. Perhaps it is just because the rest of the beer is fairly subtle, but that aroma is only going to go up with some carbonation.