Online resource listing wild yeast species

[winnph]

I will soon get started with a spring and summer project of collecting yeast samples from wild berries, apple orchards, wild cherries, and other fruit. My process is fairly simple -- I'll be streaking some plates of sabouraud dextrose agar with whatever I find on the ripe or slightly overripe fruit, and then take any promising looking (and promising smelling) yeast blooms and step them up using low-gravity wort on a stir plate.

Now I realize most of what I harvest will probably not be Saccharomyces cerevisiae, but I've been unable to find a comprehensive online resource explaining what species of yeast I'm likely to be encountering (other than S. cerevisiae), and how I might be able to identify those other species.

For example, I have some yeast that I collected from a box of bulk dates I ordered, and it produces a very pungent odor on the agar, definitely not like any brewing yeast I'm familiar with, but the yeast bloom looks very similar to brewers yeast (I streaked a plate with brewers yeast so I would know what yeast looks like).

I don't have a microscope, but if the answer is the only way to even guess what species a yeast sample belongs to is to look at it under a microscope, I might consider getting a cheap one. Even if I need a microscope, I guess what I'm hoping for is something akin to an audubon field guide, but for yeast strains.

Any thoughts?

 

[winnph]

I'd add that a good old-fashioned book would be just as welcome as an online resource, if that's the only option. I haven't added any books to my brewer's library in a few years, so I guess I'm due for an addition.

 

[theredben]

If you are not familiar with microscope identification you are probably better off making an educated guess based on the host plant. Find an appropriate yeast, and then see if the literature suggests common yeasts. Yeast occurence is not a completely researched subject.

 

[winnph]

Well my only experience with microscopes comes from (1) identifying mushroom spores (been aaages since I last did that, though), and (2) identifying microfossils in ocean sediment (part-time job in paleoclimatology lab in college, also awhile ago). So I have some experience identifying things in microscopes, but not yeast in particular.

I would have guessed that most orchards or briar patches would have dozens or even hundreds of species of yeast living in them, and that each location will produce at least a few different colonies on the agar plate (of different species).

At this point, my plan is to simply use my eyes ("is this yeast?") and my nose ("does this smell at all like something I'd drink?"), and hope for the best.

 

[theredben]

Using you nose and tastebuds sounds like the way for you to go. If you get something good you could always see if you local agricultural extension can id it for you.

 

[JohnMc]

If you can get to a college library try to find "The Yeasts: A Taxonomic Study" by NJ.W. Kreger-van Rij
(It's expensive used)
Also try this: http://www.mycology.adelaide.edu.au/Fungal_Descriptions/Yeasts/

 

[GuldTuborg]

If you can get to a college library try to find "The Yeasts: A Taxonomic Study" by NJ.W. Kreger-van Rij

OP, if you let me know what city you're in, I can tell you if any libraries own this nearby. PM is fine if you don't want that info out for the world to see. I might also be able to get you a chapter or two, if you like.

 

[winnph]

I've had a ridiculously busy week at work, so I haven't had a chance to log on and thank you for pointing me to that book. I live in the DC-area, and if nothing else I have a card for the Library of Congress. Actually, when I searched WorldCat, it looks like there are a few books by that name... does anyone know if any of the other ones are any good?

http://www.worldcat.org/search?q=yeasts+taxonomic+study&qt=results_page

EDIT: It looks like one of those other ones is a 2011 update and significant expansion, so far not available anywhere except a library in California: http://www.worldcat.org/title/yeasts-a-taxonomic-study/oclc/700701893&referer=brief_results

Second EDIT: And that library must be lying, because Amazon says it's not out until May of this year: http://www.amazon.com/dp/0444521496/?tag=skimlinks_replacement-20

 

[JohnMc]

winnph,
I gather it gets updated fairly regularly, as new scholarly studies update our understanding of the relationships between species. Torulaspora delbrueckii (German weissbier yeast) has had these names over the years:
Saccharomyces fermentati
Saccharomyces rosei
Candida colliculosa

IMHO, this will stabilize in a few years, with all the 'next gen' DNA sequencing that is and will be going on, as the sequence will allow for correction of the taxonomy (genus & species names, etc).

I'd bet the library in California got a pre-release edition or some such.

I'm glad the book is of help.