Re-Boil partially fermented beer?

[hammy48]

I brewed an RIS on Sunday and wound up with 2 gallons of 1.040 left over sparge wort and .5 left over 1.090 boiled wort... I combined them in a fermenter and was planning on adding 2lbs of DME, 2lbs of honey, water, hops, etc... Doing a second beer with the extra runnings.

Problem is, I haven't had time until tomorrow afternoon, and the wort (covered with aluminum foil on a glass fermenter) has started to ferment... Maybe it was the ridiculous amount of airborn yeast... Maybe it was the un sanitized fermenter... Anyway it's fermenting.

So if I boil this beer tomorrow how will my result be changed and is it still useable?

I want to say that the yeast has already started converting ferment able sugars to alcohol but that alcohol will be boiled off and the sugars will have already been converted... It has been producing foam for about 2 days now, noticeable more today... With about a half inch of foam on top of wort and small bubbles running up from the bottom.

Will my flavors be off in a bad way? Has anyone had this experience?

My thinking is maybe I should add more DME to compensate...

Thanks!

 

[Qhrumphf]

Sounds to me like an accidental sour mash. If the sparge runnings were never boiled, you may have gotten some a notable amount of lactobacillus from the mash grains into that extra wort. And if you boil it, it'll kill the microbes, but it wont' get rid of any lactic acid that was produced. So it may certainly be useable, but may have a defined sourness. It could also be any number of other wild yeast or bacteria from the grains, or the air, or like you said an unsanitized fermenter, and may just taste like ass.

 

[ILoveBeer2]

It will be beer. It may be good or bad. Time will tell.

 

[Joewalla88]

I don't know if this is good advice, but I'd be tempted to let it go and just see what happens. I just bottled a beer last night that I made with wild yeast I had caught. It seems like this might be an accidental version of that. I was pretty happy with the flavor so far.

I don't know though. I'm still new to home brewing. That might be a horrible idea.

 

[hammy48]

I'm going to do it, I'll post back here.

 

[jro238]

Yep, I would just let it go. It will almost certainly be sour due to the unboiled mash, but after a while it might turn out quite well.

Look forward to hearing the results

 

[hammy48]

Yeah it will be interesting if nothing else... Going to let it go for a few weeks then take a gravity and taste test. I'm not going to airlock it... Just sticking with the aluminum foil.

 

[Joewalla88]

How did this turn out?

 

[taoisilent]

It won't necessarily be sour. Some folks, after they have been brewing for a while, will have brewers yeast in the air, or a "house" strain. Or it may simply be a good wild yeast. I agree to let it go and see how it tastes when fermentation is done.

 

[Travestian]

Updates?

 

[Nightstrife]

Sounds like you may have accidently made a berlinerweise to some extent... This turn out good?