Differentiation of Yeast Strains?

[rgrim001]

How can I realistically differentiate yeast strains? (i.e. The difference between champagne yeast and beer yeast). I am getting into culturing yeast (plate cultures) and I want to understand how to tell the yeasts I am working with apart from each other.

 

[BBL_Brewer]

label the petri dish

 

[Clementine]

ask them at roll call...

without a microscope you can't.

Some yeast you can notice small difference I noticed WLP380 has a browner color when flocked on the bottom of a flask than WLP001 but nothing that is definite.

Clem

 

[PurpleJeepXJ]

If you are 'getting into' culturing yeast there is a lot more to know rather than the type of strain. +1 to labeling everything. Yeast looks like yeast and without a micro degree the normal person would have no clue. Some do look slightly different but the same strain will look different depending on the use of light dme for a starter wort and the same yeast pitched into a 5gal batch of stout will look different.

 

[cfonnes]

Brew with them. See how they "perform".

 

[thughes]

DNA testing.

 

[rgrim001]

I am talking about the determining the difference of a strain after it has been plated. I should have been more specific. I am just curious how one would tell the difference between say: brettanomyces & saccharomyces cerevisiae. AFTER STREAKED OUT ON PLATE.

 

[BeerCrafter2011]

Two different species then?

 

[Clementine]

I have not played with Brett, but when I googled images of it, it looks pretty close to what I get when I streak out regular Saccharomyces strains, too close to call IMO.

Then again make a plate and try it see if you can eye ball the difference, if you do it take some real good close up and post them, I would find the comparisons very interesting. If you have good technique you get them both on the same plate without cross contamination so you have a really good comparison.

Clem

 

[emjay]

Chris White talks a bit about this in his book, IIRC. Apparently it's possible even to differentiate between two different strains of s. cerevisiae in many cases.

The only real way to do it though is to figure it out. Take a known pure sample, plate it, and if all the colonies look the same, you can be confident of what you've got.

Take careful notes of the strain, and perhaps even a photograph. After you do this with enough strains, you can refer to your notes to get a good idea, and eventually you'll even probably be able to at least know whether a given yeast colony is an ale, lager, weizen, or brett strain - or something else entirely - just by looking at it.