Mold in starter wort?

[HeritageHD]

I made just over a gallon of starter wort the other day for a 2 stage starter. I poured 2L into my starter and the rest into a sanitized 1 gallon glass jug. I set the jug on the counter in my kitchen where it's about 68*.

When I went to pour my second stage and the wort had a slight haze to it. Today, about 72 hours later I walked past the remaining wort and noticed small whiteish dots in the foam. See pics below.

Any ideas? If it's mold, do you think my starter is junk now too?

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[HeritageHD]

There's no off smell to the wort or the starter

 

[porterpounder]

Spontaneous fermentation?

 

[IslandLizard]

Spontaneous fermentation?

This ^

Wild yeast and/or bacteria, seen it all the time.

It's sanitized, not sterilized. Your level of sanitation has everything to do with what follows...

Mold is not likely to develop within 72 hours. If they're white or green, they usually have a furry texture.

 

[IslandLizard]

OK, read it a bit closer.
You pitched the 2-3 day old wort that was kept on the countertop, and had turned cloudy, into your cold crashed and decanted starter vessel?

Chances are you now have another (wild) strain or bacteria in your starter culture, induced by the (infected) wort left on the countertop.

Is this enough to cause a larger infection or off flavors later? Hard to tell.
Most microflora in a mixture is crowded out by one that prevails, given the circumstances, some development of unwanted ones has taken place. There maybe some tartness to your beer if you ferment with it, and a persistent cloudiness. Or it becomes a full blown sour or funky beer.

I've had some successful small sour/wild batches from similar infected yeast cultures. They're interesting. However, most were not good. One was a slightly infected wheat beer yeast that was awesome!

If you like sours, try to ferment some wort with it and see what happens, maybe it's all good.

If you're after a clean beer, make another starter, the right way, from a fresh pack.

 

[GPP33]

What these guys said....there shouldn't be any bubbles in wort. Not until something starts breaking down the sugars. I'd store it in the fridge next time, actually I'd only make as much as you need for each step. Boiling some DME is pretty quick and easy.

 

[HeritageHD]

You are all definitely right. I opened the jar of remaining wort and it was under pressure.

There wasn't anything noticeable in the gallon jar when I added wort to the second stage of the starter (after first decant). The wort was clear except for some protein break and a little foam on the top but I had just shaken the jar (for no reason other than to shake it).

The original yeast is wyeast 1007 German ale that is intended for an Alaskan Amber clone. The first stage never had a krausen layer but the second stage does. So im not sure if it's contaminated or not.

Do you think I should just start over with a new smack pack, or will the 1007 overpower the wild strain? That is if it's even in there.

 

[HeritageHD]

The starter now has a sour smell to it. I don't think I'll be pitching it.

 

[HeritageHD]

Figured I'd experiment with the remaining wort so I diluted it a bit and gave it a good shake. Here it is about 5 hours later

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[jrgtr42]

I definitely wouldn't pitch my main batch with that - either make a new starter or just direct pitch the yeast (depending on time, and the second choice isn't optimal.)
However, I wouldn't necessarily completely chuck this contaminated starter.
I would think about making a larger batch, maybe an extra gallon, (or just a spare one gallon batch) and pitch some of what you get from this starter. Never know, you may get something interesting. You may not, which is why I say 1 gallon - don't want to waste too many resources and time into something unknown.