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Infected Yeast Starter? Wild Yeast?

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vortex

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(Duplicated my post from another forum to try and get some other opinions on what is going on here..)
Recently I swapped a vial of Irish Ale 1084 for a slant of Pacman with peakydh on these forums. The slant only had a very small amount of yeast on it, so I made up a 25mL starter (in a seperate, new vial), and tipped in what I could shake loose from the slant.

In 24 hours there was a nice little cake in the bottom of the vial, so I shook that up and pitched to a 1L starter @ 1040SG and put it on the stirplate.

24 hours later again, i put it in the fridge to settle the yeast, of which there was a surprisingly large amount considering I had under 1mL 48 hours previous.

When the starter had settled out, I decanted the starter beer (I didn't taste it, usually I do..) and then tipped the slurry into vials, and this is where it's done something which is a bit strange...
Here's a pic:


Click the pic for a larger image

Left 5 vials in the front row are all Pacman, right hand side are all Recultured Coopers Sparkling Ale. The thing I am concerned about is the fluffy crap on top of the Pacman, I also have a couple of vials of 1056 which have done this too (you can see the 1056 in the background on the left hand side), and another from the same 1056 starter settled out straight away and looks like the Coopers yeast.

It's either just fermenting yeast, perhaps the starter hadn't fermented out fully before I put it into vials (the other 1056 vials are still the same a month later), but even when I shake the vial it separates out to look like that in just 30 mins.

Are they infected by a wild yeast perhaps?

I was wary about pitching to a 1L starter so quickly but I don't have any anything between the vial and the 2L flask yet that I trust for my yeast - I was actually planning to decant this beer off after 24hrs and add 1L of fresh again and let it run for another 24 hrs, but after just one run there was enough yeast for the vials so didn't bother.

Starters are always run in my pantry which has no air-movement at all. Erlenmeyer flasks are cleaned with PBW (at least 24hr soak after a starter) then when making up the wort they are boiled for at least 10 - 15mins with the dme/water in the flask itself. I always use foil on the flasks, always put on the flask prior to boiling so the steam sanitises the foil. Usually the foil gets a starsan prior to going onto the flask. Stirbars are always starsan'd, never boiled. The 25mL vial used foil to cover it, was quite tight around the neck. Erlenmeyer opening is flamed (with a kitchen stove lighter, might not be hot enough) prior to transferring to the vials. Only improvement I can think of would be to work next to an open flame when transferring yeast.

Thoughts?
 

mkstalen

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Can't help with your question... But where did you get your vials? They look perfect for keeping samples/slants in.
 

vykuza

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It kind of looks like a krausen. Maybe the starter hadn't fully fermented? Do you get gas release when you crack the lid?
 

JoeF

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Can't help with your question... But where did you get your vials? They look perfect for keeping samples/slants in.

The vials are from here - LINK

I actually just bought 50 of them and only need probably 25 if you want to buy some? Cost price of course + shipping.

Don't mean to threadjack - just trying to help!

PM me if your interested.

Cheers
 

vortex

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The vials are from here - LINK

I actually just bought 50 of them and only need probably 25 if you want to buy some? Cost price of course + shipping.

Don't mean to threadjack - just trying to help!
No problem. That's the ones, they come sterile, so they're super easy to use and ready to go.
 

Wolfy

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Curious and interesting, however I don't think it would be a wild yeast because at fridge temps they're not going to be happy and likely the Pacman already fermented most of the usable sugars. Your procedures and sanitation also appear to be pretty good. But it makes me wonder if there is some sort of infection that likes low temps and behaves like you are seeing.

I'd suggest you take one and step it up into a decent size starter and give it a good smell/taste test and see how it goes - like you said it could be that the yeast was not finished when you packed it and it's just de-gassing a bit or something like that.
 

Goldenchild

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I had the same thing not too long ago with some wlp400 I had harvested from a batch.
Went away after a 3-4 weeks in the fridge temps. used 1 and was fine no sneaky infections. :)

If you are really worried possibly try top cropping some yeast from the Krausin and step it up.
If it dosnt resemble pacman and smells/tastes funky you might be in trouble. If it smells fine it probably will be.
Goodluck and nice score on the pacman would love to use this one sometime soon.
 

vortex

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Examined these tonight closely, definitely just bubbles - one of them I shook up a lot and cracked it open, yeast everywhere. Didn't bother trying to save it, but I tipped it in a glass and tasted it - strong flavours, but not infected as far as I can tell.

I'll culture one up again I think and see how it goes.
 

felten

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I've had the same thing with wyeast1968, probably due to it's super flocculating powers
 

Midnight Brew

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I've had the same thing happen when top cropping. I always presumed it was because the yeast hadnt finished fermenting and is still in its super active stage. After a few days to a week or more it should fall back in. Be careful of C02 build up in the vials if they still are super active. Can release the pressure by filling a bucket with starsan and place the vial under the solution and gently crack the lid to release the pressure. Then tighten up and back in the fridge.
 

micblair

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I've had the same thing happen when top cropping. I always presumed it was because the yeast hadnt finished fermenting and is still in its super active stage. After a few days to a week or more it should fall back in. Be careful of C02 build up in the vials if they still are super active. Can release the pressure by filling a bucket with starsan and place the vial under the solution and gently crack the lid to release the pressure. Then tighten up and back in the fridge.
Bacteria don't have wings, nor can they crawl. Probably overkill. If anything, while the lid has been cracked, spray the exposed area with 70% ethanol-water.
 

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