Restarting A Frozen Whitelabs Tube

[Goose]

Hi guys, found an thread on this topic but it was so ancient thought I'd start a new one.

I picked up a tube of whitelabs ale yeast that had been froze for 6 mths from a supplier that "accidentally" froze some stock and kept it that way. Contents were brown, and while not ideal thought I'd try to start it up and give it a go for an experiment.

To do this I prepared a wort of 4 litres with 440 g of DME, boiled with 1 tsp yeast nutrient and cooled to room temperature. I did a large volume because I only have a 8 litre jar with airlock and figured to do anything less may be too much headspace...

Anyway, after 4 days its definitely fired up, quiet a large deposit settled on the base of the jar and what looks like a healthy foamy mass on the surface as well. These yeasties must be tough little critters, everything I'd read suggests freezing would kill them off.

Now of course I'm a little reluctant to use this for a starter .... :huh: becasue I am not totally sure what I have started up.

How can I tell that the starter has not become infected or contaminated in anyway ?..... I'd hate to waste 5 hard hours of wort prep by ruining it with a wild yeast strain... :unsure: . I know I could taste it, but have read that the "beer" above a starter tastes pretty bad period.. so how ?


Goose

 

[Darren]

Could have started it in a couple of hundred ml in a PET bottle. Smell and taste is the only way.

cheers

Darren

 

[Weizguy]

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I know I could taste it, but have read that the "beer" above a starter tastes pretty bad period.. so how ?
</abbrev>

Goose

Goose, that's a load of old rot. Don't believe anything you hear and only half of what you see.

The yeast culture wort may taste a litle funky/yeasty/estery, but it should taste clean and beery.

I just sampled yeast starters the other night from some old recultures of Bavarian lager, Danish lager II and YeastLabs L31 Pilsner. All tasted clean and nice/lagery. Wish I'd made a bigger starter (he he). :lol:

You could prob scoop some yeast off the top of the foam cap and cultue it if it's a top cropper, and it sounds like this may be one.

Seth's 2 cents

 

[razz]

Use your senses Goose. If it looks, smells and tastes like crap then it is !

 

[Goose]

thanks dudes.

I'll try the pet bottle trick next time. Suppose I could drill a hole, insert a bung and an airlock in the lid.

Well I have not tasted it yet but the fermentation smesll coming from the airlock seem normal to me. I'll let you know how it tastes though....

So how do u reckon this ol frozen yeast started up then ? I was surprised at how fast it did start up.. I assumed freezing damages cell walls etc and really did not expect a positive result.

Goose

 

[Weizguy]

Goose,

Maybe it's due to the sheer number of yeast cells in the original vial.

Even if only a small percentage of a billion cells stay viable, you still have a fair number of cells.

I'm still a little surprised that it took off so quickly. It may not have been frozen for long and the cells in the middle of the yeast cake were insulated and protected? Very lucky, I'd say!

Freezing kills cells due to tiny ice crystals forming and penetrating cell walls and all the micro-tiny cell organelles. Stabbed to death, from within. Very yucky to contemplate.

Go the PET bottle yeast culture. Works for me, since 1997!

Seth out

 

[lucas]

I'll try the pet bottle trick next time. Suppose I could drill a hole, insert a bung and an airlock in the lid.

No need, it's PET. It can take a lot of pressure without breaking, I just crack the lid everytime it feels rock hard and squeeze most of the CO2 out

 

[///]

DO a pH test - infected beer is usually lower. Check with the Supplier on what pH the yeast normally works at.

Scotty

 

[pint of lager]

Am very impressed that a test tube of yeast was frozen, then kicked a 4 litre starter off within a few days.

Some time ago, I used the method of yeast in glycerine frozen as a slurry to make starters, and after a year or so, it didn't kick starters off too well.

Next time, as others have suggested, aim for a lower volume of starter. One of the rules of yeast work is the smaller the amount of viable yeast, the smaller the starter. For instance, yeast grown on agar in petri dishes, a matchhead of yeast is used to start off about 50ml of sterile wort, then stepped up in 10's from there. If you had posted before making your starter, I would have suggested 500ml maximum.

Fortunately, your starter kicked off well. Because it kicked off so strongly, I don't suspect your yeast is mutated. If it had been very slow to work, that would have meant much less viable yeast in the original tube and more likelyhood that mutations had occured.

The ability to attenuate and flocculate are supposed to be the first properties to be changed as yeast mutates and can be used as a guide to yeast health. Take an sg sample and monitor how quickly your 4 litres takes to flocculate compared to the normal yeast properties as listed on the whitelabs site. This would show up quickly if a yeast farmer selected only one colony off a plate and selected a mutated colony. But I think you will be right to use your yeast.

 

[Goose]

DO a pH test - infected beer is usually lower. Check with the Supplier on what pH the yeast normally works at.

Scotty

thanks lads.


the last starter I did (got a SAFALE going but only for a few hours) the taste of the starter was a tad sour... but I pitched and beer turned out fine. Was wondering if this was normal... :unsure: ?

so ph u reckon... well in fact I do have a meter so will check.


pint, thanks for the heads up. Do you think I could split the 4 litres into separate starters (PETS) , and store them ? I am just wondering whether there would be sufficient population in this mini brew I have concocted to make 4 x 1 litre pitchable starters.

Goose

 

[pint of lager]

Goose, I wish I could give you a definite answer, but it is impossible.

You may have got everything right. The yeast and your sanitation methods are perfect and the sample could be split four ways. Or, it may have a slight infection and while this may not show in the first brew, the next will be infected and you will curse my advice because you will throw a whole brew out.

In theory there should be plenty of yeast to split four ways, store in the fridge, then a few days before you brew next, pour off the waste beer and pour in fresh wort to make a new starter.

It is not a good idea to make starters from sachets of safale, or any dried yeast. A sachet already has a large number of yeast cells, and if you pitch this to a litre starter, they are competing for limited resources and will not grow properly.

I suspect from your posts that this is your first go at making yeasts and starters. So keep the bar low and aim for one or two brews from this yeast sample.

 

[Goose]

I suspect from your posts that this is your first go at making yeasts and starters. So keep the bar low and aim for one or two brews from this yeast sample.

Hey Pint,

U're dead right. First time for everything.

Noted on starting up the dried yeast, I was just doing this to get it going as I have noticed that a mere hydration sometimes still means a pretty slow start to the fermentation.

Perhaps I'll give it a few more days to fully chew out the wort sugars and then split it 4 or more ways, and maybe I'll give one a whirl with a kit beer (FAR less hassle) or all DME to see how it goes. If its a success I'll use the next one(s) on a full AG wort.

To fire these "starters" back up, assuming they are sealed in PETS u reckon I should just drain off beer from original starter and add another 500 mls wort directly to the same bottle ?

Cheers

Goose

 

[Trough Lolly]

G'day Goose,
You're getting plenty of good advice on the thread, but I just wanted to cover off a point Darren made earlier (which I agree with, too!)...

I suspect the main reason why Darren suggested the smaller starter was to allow you to revive the yeast in a small solution and then step it up to, say, 4 litres, over a few of days. By doing this, you force the yeast to multiply in population and you end up with a much bigger population of healthy yeast in the final 4 litre starter.
I'd lay good money on a side by side comparison that a 500ml starter stepped up over a week to 4 litres will result in a much larger yeast colony than dumping a tube of yeast into 4 litres of fresh wort.
Cheers, and congrats on reviving the frozen tube.
TL

 

[Goose]

I'd lay good money on a side by side comparison that a 500ml starter stepped up over a week to 4 litres will result in a much larger yeast colony than dumping a tube of yeast into 4 litres of fresh wort

Thanks Lolly, I dont doubt that from what I have learned in recent reading.

However I'm surprised that a yeasty knows whether its in 40ml, 400 ml, or 4000 ml of wort when its presented with a new substrate. What is this, some kind of yeasty teamwork ? I am aware that I want yeast multiplication/growth, and not just beermaking ... so how does this work ?

Goose

 

[keat]

Now of course I'm a little reluctant to use this for a starter .... :huh: becasue I am not totally sure what I have started up.

How can I tell that the starter has not become infected or contaminated in anyway ?..... I'd hate to waste 5 hard hours of wort prep by ruining it with a wild yeast strain... :unsure: . I know I could taste it, but have read that the "beer" above a starter tastes pretty bad period.. so how ?

If it smells like sewer/sweaty socks/stale sweat/rubbish bin or generally unpleasant, its contaminated. Toss it. Otherwise, it should be good. There're no hops aroma to cover any off smell/tastes, so it should be easy to spot.