# Yeast Species And Yeast Blends



## kirem (10/2/09)

I am doing some yeast species and yeast blend trials on some red grape varieties this vintage. I was doing a bit of research on them and found this;

_Torulaspora delbrueckii
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Torulaspora delbrueckii
Scientific classification
Kingdom: Fungi
Phylum: Ascomycota
Class: Hemiascomycetes
Order: Saccharomycetales
Family: Saccharomycetaceae
Genus: Torulaspora
Species: T. delbrueckii
Binomial name
Torulaspora delbrueckii
Lindner, 1904

Torulaspora delbrueckii is a yeast species which is also known as Saccharomyces delbrueckii or Saccharomyces rosei (anamorph called Candida colliculosa)

The genetic analyses have revealed that the various strains treated as Torulaspora delbrueckii actually represent different species (and belong even to different genera, like Debaryomyces, Saccharomyces and Candida). Thus, the criteria of the species T. delbrueckii apparently needed some revision according to the type strain (the strain SANK 50118).

One interesting usage of T. Delbrueckii (and quite possibly one or more of the similar Saccharomyces strains) is in brewing German-style wheat beers. During fermentation the yeast produces noticeable banana-esters and clove-like phenols which impart the distinct aroma typified by these beers._

Could be interesting in a wheat or rye beer.


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## FreemanDC (10/2/09)

Isn't Candida thrush ? like the infection ?.

hmmmmm............................... :huh:


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## kirem (10/2/09)

I think it is. I wouldn't recommend dipping yourself into your ferment and go and see a doctor before it gets out control. Has anyone commented that you smell of bananas or cloves?


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## FreemanDC (10/2/09)

No, but the girlfriend won't touch it.

hmmm..... free yeast, i'll make a couple of slants for everyone.

ok better edit that.





Jokes.


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## kirem (10/2/09)

hmmm, I think you should explain which end is for drinking and which end is for.....well....not drinking


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## FreemanDC (10/2/09)

Ahh well, i've had my fun.

I'll leave this for the experts.


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## unterberg (10/2/09)

Well the Australian strain collection doesnt have it.
You would need to get it from Europe or America e.g. Here
Could be tricky to get it through customs even if you are working in a lab....


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## caleb (10/2/09)

Well this thread seems to be heading right for http://toisennhauser.com/work/12/oktoberfest

Back to the original topic:
I know many wines are made using a lot of wild yeasts which end up on the grapes naturally. I wonder how many of these have ever been cultivated and considered useful for beer making?

We have endless strains of _s. cervesia_, and the odd _brett._ is sometimes used, along with a few 'lambic' cultures, but are there any other species of yeast which might make a good beer?


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## kirem (10/2/09)

I already have it and it was sold to me by the rep for CHR Hansen.

No I don't work in a lab and no I don't need to get it from America or Europe.

Just because the Australian strain collection doesn't have it, doesn't mean much. When I did my honours project on Dekkera, there were plenty of strains that the collection didn't have but other research groups did.


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## kirem (10/2/09)

Caleb said:


> Back to the original topic:
> I know many wines are made using a lot of wild yeasts which end up on the grapes naturally. I wonder how many of these have ever been cultivated and considered useful for beer making?
> 
> We have endless strains of _s. cervesia_, and the odd _brett._ is sometimes used, along with a few 'lambic' cultures, but are there any other species of yeast which might make a good beer?



Quite a few would probably work. The thing with true 'wild' yeasts is they don't tolerate alcohol or SO2 and are easily and quickly out numbered by saccharomyces cerevisiae. So they generally work for a while and then die. I think there is a big future in non-saccharomyces yeast. The bags of yeast I have are mixtures of yeasts, specifically blended to provide dominance of a specific strain/species at specific times during the fermentation. Produced by CHR Hansen - trade names melody harmony rhythm and a few others, basically different ratios of the three yeast species.

When I make my own wine I normally let whatever wild yeast have a go for a couple of days (after the initial signs of fermentation), maybe a 2 baume drop then I add a known saccharomyces strain to carry out the fermentation. Some winemakers take the grapes at the vineyard and culture them up into a starter, well away from the winery environment, to avoid any 'wild' yeasts from the winery (that are really just commercial selections floating around in the winery)

Wild ferments are rarely that in wineries, there is so much of commercial selection yeast strains floating around from other fermentations and winery operations that they are not normally a true 'wild' yeast.

Saccharomyces especially commercial strains are so effective at dominating a fermentation (short lag phase, some have killer activity, tolerance of high alcohol and SO2 etc etc) that anything else that 'may' be in the winery is easily out competed until you get to an environment low in nutrient and carbon source where something like dekkera/brettanomyces dominates.

Playing with 'wild' yeasts is good fun, add in the change in fermentation characteristics due to natural selection and genetics and it becomes good fun and too risky to tell your boss about until you make something special and then you wait to tell him over a few beers.

I am not sure that treating malt in similar fashion to grapes would give you something interesting, I suspect you would have bacteria issues.

I hope Darren sees this thread and takes the time and effort to write something and share his knowledge.


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## kirem (10/2/09)

maybe plating out some malt grains on a specific agar that doesn't allow bacteria to grow and then picking out different colonies and plating them out and culturing them up once you have isolated a single species and strain (maybe) and conducting fermentation trials might yield something interesting.

My bet would be that anything useful on the original barley would be killed in the malting process.

Perhaps the above selection process using malting barley might throw something up.

Perhaps making a wort and leaving that out somewhere to pick up air born yeasts and isolating those species and strains might give you something. 

Where for art thou Darren??????


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## Thirsty Boy (11/2/09)

Kirk,

There was an episode of the brewing network prior to christmas that featured a winemaker who has been doing quite a bit of experimenting with wine strains in beer and blending strains... mostly still sach cerevisiae of some description.. but not normal "beer" strains.

This links in a little with your topic, you might be interested in it; and I would be really interested in the thoughts of another winemaker about the things that are described on the show.

The thing I am starting to realise.. is that you wine guys know a lot more about yeast than the beer guys do. The sheer amount of knowledge in how to manipulate a fermentation with temperature, rousing, racking and a bunch of other things that winemakers do - I think there is tremendous potential for crossover into the beer world and your post confirmed it for me.

Not to mention the skill you guys have in oak manipulation (also covered in the show) and blending.

Here's a link to the show - I have listened to it a couple of times and I am starting to understand a little... I'm guessing that it wont strain your brain nearly as much 

Brewing Network - Wine Yeasts in Beer


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