Possible Infection

[glennheinzel]

I'm hoping that someone might be able to help identify if my starter is okay or infected, although I appreciate that the information presented may be inconclusive.

I made up a 1 litre starter to step up a fresh tube of WLP830 (lager yeast). The demijohn, bung and airlock were all properly cleaned and sanitised (napisan and Iodophor).

I didn't boil the water or DME. I also didn't sterilise the bowl (for measuring the DME) or the funnel (for getting the DME into the demijohn) as I figured that trying to sterilise them would only make the DME stick to it.

I don't have a stir plate so I gave the demijohn a good swirl round whenever I was near it. I left the demijohn at room temp for a few days and then placed it in the fridge (at 5 deg C) to drop the yeast.

After a few days I notice that there are a few white spots on the walls of the demijohn (see pic below). There are no white spots floating on the surface of the starter.

Is there any conclusive proof that the white spots are just lager yeast that has grown on the side of the demijohn (due to regular stirring/shaking) or do I have to admit defeat and concede that it is/might be an infection?

 

[silvana]

Conclusive proof ? All in the smell and taste but it dosent look good.

Next time sanitize everything (everything including the bowl, bench, your hands, the vial etc etc). You really have to boil the water and DME, if its infected it would prob be from that.

Hope its not.

 

[glennheinzel]

I need Petesbrew (aka Sample King) to help me out.

 

[petesbrew]

Why can't I see some images? All I see is a little box with an X in it.

Sorry Glenn, but I'm the LAST person to ask! :lol:
I have to admit, I'm probably the laziest yeast starter here, but so far I've had more good luck than bad.

Lately the most sanitising I've been doing is pouring boiling water into my bottle (and letting the bottle cool) before I throw in the LME, water & yeast.
I've opted for alfoil over the top, rather than the bung & airlock, and it seems to work.

Hope it's all good, and just a characteristic of that yeast.

 

[chappo1970]

Rukh

Smell and taste it. If you drop dead it's infected, if you only go into convulsions it's 50/50 and if you get a mild face twitch it's prolly just ok? :lol:

Seriously have a smell and taste if there's any off smells don't taste if smells like yeast/bready have a taste.



Cheers



Chappo

 

[glennheinzel]

The feedback from the WhiteLabs team is that it is probably mold growing on the carboy due to the headspace. They reckon that I should make a fresh starter, although the current starter may be savageable because-
"the mold won't survive the brewing process (they only grow in the presence of oxygen), it can cause off-flavors in the starter wort, which can lead to off-flavors in your beer. You might want to pull a small sample and taste/smell it to make sure it is still yeasty and not moldy. It can still be risky because transferring the yeast to your wort can cause pick-up of mold spores, which can spoil the wort before the yeast has enough time to consume the oxygen."

I've drained the starter into a much smaller jar and will check it again in a few days.

Tips that they offered are-
* Boil the water and DME.
* Use a container no more than twice the starter volume. ie, Use a 2 litre container for a 1 litre starter.
* Two days is more than enough to let your starter grow. After that, you will start to see some fermentation and yeast degradation.

 

[manticle]

Not so much a concern for the DME but I'm surprised you wouldn't boil the water. Yeast is a micro-organism you're wanting to grow but at the same time you want to limit the opportunity for any other micr-organisms to grow.

I'd cut my losses - better to lose a starter than a whole brew (says the man who's looking for a suitable to place on the lawn to chuck his).

 

[glennheinzel]

Not so much a concern for the DME but I'm surprised you wouldn't boil the water. Yeast is a micro-organism you're wanting to grow but at the same time you want to limit the opportunity for any other micr-organisms to grow.

I'd cut my losses - better to lose a starter than a whole brew (says the man who's looking for a suitable to place on the lawn to chuck his).

You're right, its not worth the risk. Back to Dave's Homebrew for me tomorrow. Does anyone need me to pick up anything for them?! h34r:

 

[Doc]

I don't have a stir plate so .....

That is a problem we have to fix.
I see a weekend arvo build project coming up

Doc

 

[Renegade]

You're right, its not worth the risk. Back to Dave's Homebrew for me tomorrow. Does anyone need me to pick up anything for them?! h34r:

A revised pricelist would be a good start.

 

[syd_03]

You're right, its not worth the risk. Back to Dave's Homebrew for me tomorrow. Does anyone need me to pick up anything for them?! h34r:

Missed the boat on that one, I need a few items.