Has My Yeast Starter Been Infected?

[beardown2489]

I have a couple variables. But first. The pictures.

View attachment ImageUploadedByHome Brew1430361749.573112.jpgView attachment ImageUploadedByHome Brew1430361775.378113.jpg

so my two notes to include would be

1. I made the starter bigger than normal, and it had krausened over the top of the flask and onto the stir plate. I had used a sterilized piece of aluminum wrap to cover it originally.

2. I was out of plain light DME. I ended up using Bavarian wheat DME. Would this make any difference? I don't think so, but it's a unique situation to me so I figured I'd mention it.

Let me know your thoughts. It's US - 05. It's been in the fridge for about 6 days and released quite a bit of pressure when I opened an hour ago.

Thanks guys.

 

[beardown2489]

It smells ok. It still smells like yeast I guess

 

[Turkeyshot]

From the pictures it looks fine and if it smells okay, I don't see why there would be anything wrong with your starter.

 

[Gavin C]

US-05 is a dry yeast. Making a starter is contra-indicated and potentially detrimental to the yeast. A minimum of 2l of DME is needed to double the yeast count. Cost prohibitive given the cheap cost of a second pack.

Starter with wheat DME means the yeast are now trained for a wheat malt based wort. Ok if your doing a wheat. Desirable in fact. Not so for a non wheat malt based wort.

Re: infection. Possible. Who knows. It's not a starter I would want to use given what you have described. $4 for a new pack of S-05 would be my plan for what it's worth.


I like to follow the Fermentis guidelines to the letter when it comes to getting the best from their great products. Rehydration of the dry yeast is simple and effective.
Best of luck with the brew.

Edit. Mason jar bombs can happen when fermenting yeast are sealed in. Not a good idea to do that with an unfinished starter.

 

[SteveHeff]

What would have infected it? It sounds like your techniques were fine...as long as the vessel was clean/sterile before you used it and your water/wort boiled, I don't see what the problem is. There are not any issues that would arise by using bavarian wheat DME. Looks fine to me.

 

[beardown2489]

I'm sorry it is 1056. My error there

 

[beardown2489]

@gavin I only use the lid for the first few days just be sure. I was very surprised to see the pressure. Which is what lead me to question if it's infected.

 

[Turkeyshot]

US-05 is a dry yeast. Making a starter is contra-indicated and potentially detrimental to the yeast. A minimum of 2l of DME is needed to double the yeast count. Cost prohibitive given the cheap cost of a second pack.

Starter with wheat DME means the yeast are now trained for a wheat malt based wort. Ok if your doing a wheat. Desirable in fact. Not so for a non wheat malt based wort.

I could agree with you on the part of using wheat to make the starter, but not completely on the part about making a starter. Isn't making a starter just a mini batch of beer anyways? So wouldn't the starter, even if it was smaller still help increase the yeast count? Even from starting with dry yeast.

 

[brew_ny]

that is what a top fermenting yeast looks like

 

[Gavin C]

I could agree with you on the part of using wheat to make the starter, but not completely on the part about making a starter. Isn't making a starter just a mini batch of beer anyways? So wouldn't the starter, even if it was smaller still help increase the yeast count? Even from starting with dry yeast.

No. Not if half the yeast are killed when they are pitched dry into the starter. 2l starter to get you back to where you were in the first place minus all the goodies the pro yeast guys and gals have worked so tirelessly to incorporate.

A pointless and counter productive task.

OP has used 1056 so that is moot.

Starters need oxygen. Placing a lid or airlock is contra-indicated also. No addition,a O2 can get in. Not to mention the risk of explosion with a lid. Not getting that bit I'm afraid.

 

[Turkeyshot]

No. Not if half the yeast are killed when they are pitched dry into the starter. 2l starter to get you back to where you were in the first place minus all the goodies the pro yeast guys and gals have worked so tirelessly to incorporate.

A pointless and counter productive task.

But that is if they are pitched dry into the starter. That would not be the same case if you rehydrated the yeast first.

 

[beardown2489]

No. Not if half the yeast are killed when they are pitched dry into the starter. 2l starter to get you back to where you were in the first place minus all the goodies the pro yeast guys and gals have worked so tirelessly to incorporate.



A pointless and counter productive task.



OP has used 1056 so that is moot.



Starters need oxygen. Placing a lid or airlock is contra-indicated also. No addition,a O2 can get in. Not to mention the risk of explosion with a lid. Not getting that bit I'm afraid.

Maybe I should be more clear.

I used a stir plate. I lightly cover it with foil.

While at work. (Somewhere between 14-22 hours, the flask reach krausen and was spilling over the edge of the flask it was stirring in.

At this point sterilized a growler and let it finish up for a day. Then split this up into a few mason jars.

Mason jars have a lid and a screw on top and placed them in the refrigerator.

I normally just place the lid on the mason jar for a few days as I've heard horror stories about yeast starter bombs.

After a few days I screwed the top on over the lid.

Then when I opened it 6 days later it released pressure. This confused me. I have never had this issue before. Probably about 25 successful starters over the last year.

The only time I can think of that would have infected it would be the time while I was at work and it was spilling out of my flask. My sanitation has never been an issue prior to this but I made a starter that probably needed to go in a 2 liter flask and chose the 1 liter flask because my 2 liter was at a friends house

 

[OleBrewing]

I wouldn't have used wheat for a starter base because of the foaming abilities, of course in a pinch I probably would've done as you did.
Let her/him (depending how you label) buck, it will be fine.

I have also in a pinch used one packet dry yeast in a 2 liter starter 8-10 hours before pitch to 10 gallons of wort, started fermenting in an hour.

 

[Gavin C]

But that is if they are pitched dry into the starter. That would not be the same case if you rehydrated the yeast first.

Yes. Then 2l starter with 200 g of DME to try to double the count. Again losing lots of the goodies the Fermentis crew have built in.

Or buy a second pack. $4 v Costs of 200 g DME plus time and effort to make starter ferment it, crash cool it decant it.

I would reiterate. Pointless needless and counter intuitive effort. I don't see the rationale I'm afraid.

 

[beardown2489]

I wouldn't have used wheat for a starter base because of the foaming abilities, of course in a pinch I probably would've done as you did.
Let her/him (depending how you label) buck, it will be fine.

I have also in a pinch used one packet dry yeast in a 2 liter starter 8-10 hours before pitch to 10 gallons of wort, started fermenting in an hour.

Yeah. I wonder if regular DME would have foamed over with the same volumes. I hadn't made a starter of that size before in that flask. Normally something this size goes in a bigger flashed. I thought it would be fine. Looks like the wheat DME got me.

 

[beardown2489]

Still not sure what to do here.

Are there any tests I could do? Could another starter with this yeast make it very obvious?

 

[chickypad]

Starter with wheat DME means the yeast are now trained for a wheat malt based wort. Ok if your doing a wheat. Desirable in fact. Not so for a non wheat malt based wort.

You got some data on that? Is the sugar composition of wort from wheat malt significantly different from barley wort, and if so is it enough to hinder the yeast? I use whatever DME I have on hand for starters including wheat. For what it's worth it looks like Mr. Wizard uses it too.

As far as your starter OP, I've never sealed a starter with a lid but I've certainly seen off gassing taking out harvested yeast in mason jars from the fridge. That thing looks pretty active though, maybe it wasn't done?

 

[Gavin C]

You got some data on that? Is the sugar composition of wort from wheat malt significantly different from barley wort, and if so is it enough to hinder the yeast? I use whatever DME I have on hand for starters including wheat. For what it's worth it looks like Mr. Wizard uses it too.

As far as your starter OP, I've never sealed a starter with a lid but I've certainly seen off gassing taking out harvested yeast in mason jars from the fridge. That thing looks pretty active though, maybe it wasn't done?

Thanks for the link @chickypad . Much appreciated. Looks like I have completely got the wrong end of the stick on that one. It appears yeast does't give a hoot what source the maltose comes from in a starter. Thanks for pointing out my glaring error. My apologies to the OP @beardown2489 for the poor advice on my part, with regard to that part of your post.

My thinking was backward. When doing Weissbiers I have always used wheat DME for my starters thinking it was for this reason. But no, it would seem that it has more to do with preventing darkening of a wheat beer with DME based starter. This is of minimal or no concern anyway and completely of no concern if doing it the other way round, which you are, a wheat starter for a barley beer.

Given everything I reckon the starter would be OK to use

• WYeast 1056
• small starter
• Probably no contamination
• Wheat DME a non-issue

 

[beardown2489]

I dumped it.

Sorry to break the rules boys. It wasn't my only sample of the strain. I just wanted some feedback.

I'm going to chalk it up to the overflow that occurred.

If I'm wrong, I'll never know. But id rather dump it than taint a good batch of wort.

Thanks.

Glad to learn that the wheat wasn't the issue. I'll keep this in mind. As long as there is maltose, it seems the yeast will thrive.

 

[kombat]

US-05 is a dry yeast. Making a starter is contra-indicated and potentially detrimental to the yeast.

Man, you really love that word, don't you.