recognizing yeast strains?

Hi,
I've got a couple of vials of frozen yeast strains from a friend of mine. Unfortunately labels from two vials came unstuck :-( These were ESB and Czech Pils from Wyeast. Do you have any idea how could I recognize which one is which?
I'd be grateful for any suggestions
Y

yemu said:

Hi,
I've got a couple of vials of frozen yeast strains from a friend of mine. Unfortunately labels from two vials came unstuck :-( These were ESB and Czech Pils from Wyeast. Do you have any idea how could I recognize which one is which?
I'd be grateful for any suggestions
Y

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If the yeast was frozen, you might not have to worry about what was what (ie: it might be dead).

If the yeast was frozen, you might not have to worry about what was what (ie: it might be dead).

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Unless the yeast was mixed with glycerin before freezing to prevent rupture of the cell walls.

yemu,

I'm afraid there's no way to tell the strains at a glance. Are you familiar enough with the flavor contributions of those yeast strains to identify them in a controlled tasting?

of course they were frozen with glycerin,

I'm afraid I won't be able to recognize these yeast strains by smell. I was wondering if I made a starter i'd be able to recognize which strain is in the starter? After all one is an ale and one is a lager strain.

You should be able to tell these strains apart by the taste of a starter. An English ale and a European lager should be significantly different. But unfortunately you have to defrost both or just one and hope that you can tell if it is a lager or ale. The temperature at which they work should also be an indication in your case.

If you had some raffinose you could test ale vs. lager. An ale can ferment raffinose only partially so the amount of alcohol or CO2 produced would be less. But I wouldn't even know where to get raffinose nor do I think that this level of involvement is necesary.

Kai

I can defreeze one vial, make a starter, and then after it ferments freeze a couple of vials.

So the plan is:

1. I take one unlabeled vial
2. Make a starter
3. Ferment it at 20C/68F, even a little higher.
4. Check the smell and gravity after 2 days

If this was ESB, it will ferment significantly, if it's Pils it won't.
If it's ESB it's fruity, if Czech Pils it's not.
Am I right?

If it's ESB I freeze it with glycerin and label ;-)

If it's Pils I put it in the basement in 12C/54F, wait for it to ferment, then freeze and label.

The question is if 68F will harm lager yeast?

What do you think about my plan in general?

The pils will also ferment well at 68F. All yeasts like it warm, but some yeasts can also ferment cold. It should be the distinct fruitiness between the two beers yeast that you will notice.

Kai

ok,
so I understand, I can prepare the starter in 68F and then if it's fruity it's ESB, and if it's not it's Pils. Then I freeze, label and I'm good;-)

I would think the ESB, especially if it's the Fuller's strain, would be noticeably more flocculent than the Pilsner. An ESB starter would have a flying cottage cheese appearance, the lager starter more creamy.

Throw them a handful of raffinose. The one that comes and eats it, it's the lager strain :cross:

Seriously: maybe try to make a cold starter, in the fridge, 9-10*C. I'm sure ESB won't work that cold.

Piotr said:

Seriously: maybe try to make a cold starter, in the fridge, 9-10*C. I'm sure ESB won't work that cold.

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Thats whwat I was thinking. Pick one, make a starter and ferment it at lager temps. If it ferments, there's your Pils, if it does nothing, most likely there's your ESB.

Hi all,

I made a 100ml starter from one vial, and then stepped it up to 1l. now it sits on a stirplate, and it smells awful! I don't now which one it is (pils or esb), but it smells like cooked cabbage or corn - it seems that it was infected and the DMS comes from the bacteria. I don't know if it's a vial or my sanitation. I'm sure I won't risk pitching it :-(

unfortunately the other vial was not sealed properly and leaked, so I had to throw it away.

so, to sum up, the problem solved itself...