Crossing Yeast Strains

[Nick JD]

Does anyone know under what conditions yeast can be forced into sexual reproduction instead of their usual asexual "budding"?

I'm wondering if it's possible for a homebrewer with a few jars to breed a specific yeast strain of their own by crossing two of their favourites and hoping for both's desirable characters.

 

[Brewer_010]

Not sure of the technical aspects of this but I have a weizen that, when the Danstar Munich yeast didn't fire, I plopped in a US-05. The result is a clovey, tart weizen with a relatively clean dry finish. Obviously the two strains have blended to some degree...

 

[bradsbrew]

I am interested in this too. I was thinking of mixing some 1275 and 1968.

Brad

 

[jonocarroll]

Not sure of the technical aspects of this but I have a weizen that, when the Danstar Munich yeast didn't fire, I plopped in a US-05. The result is a clovey, tart weizen with a relatively clean dry finish. Obviously the two strains have blended to some degree...

Be careful with your use of the word 'obviously' please - if I cook a casserole with pork and lamb, the result will have some flavours from each, but I wouldn't say that they 'obviously started posthumously mating in the pot'.

The two yeasts you have used have just competitively fermented some sugars, and produced their respective by-products.

I would have a look on Google for some answers to this question... this link for example seems to have a few clues. It doesn't look particularly easy to actually get the yeast mating properly, but to get a blend of yeast is simple - just combine them (as Brewer_010 has done). Wyeast even sell various blends of yeasts that give particular qualities.

 

[rclemmett]

Does anyone know under what conditions yeast can be forced into sexual reproduction instead of their usual asexual "budding"?

I'm wondering if it's possible for a homebrewer with a few jars to breed a specific yeast strain of their own by crossing two of their favourites and hoping for both's desirable characters.

But what would happen if you only got their undesirable characteristics?

Seriously though, there is a good article in Decembers issue of BYO on mixing yeast strains. I feel that is probably about as close as you will get as a homebrewer without a lab.

I also didn't think yeast bred... I thought that individual strains could be isolated and then mutated/evolved.

 

[Spartan 117]

OK.... I'm no biologist so if what I say is wrong don't flame me for it.

As far as I am aware, which adds to what quantum brewer says, is that the yeast will compete for the available nutrients, generally the one best suited to the conditions will thrive the best and possibly eliminate other strains, however if you're willing to invest a bucket load of time it is possible to develop "new" strains. The reason we get new strains is that yeast will mutate everytime they "copy" themselves, these mutations come from inevitable flaws in the copies, some mutations are good some are bad, and its wether or not the mutations aid or hinder the cells growth and ability to survive that drives the evolution of the sub-species. Now lets say you wanted to get a yeast that worked well in colder temperatures, basically (very very very basically) all you need to do is put a yeast strain that doesn't handle the cold too well but will survive and put it somewhere cold give it some food and after a few thousand generations (maybe less maybe more) there will be certain yeastie-beasties that will thrive in those circumstances, due to the mutations from copying that enable it to process its food better or generate more energy from the food etc, and these will out compete the rest resulting in a strain of yeast which do best in the cold, now this is a very general overview of the whole process but fundamental none the less

There was a post on here not long ago asking about the origins of yeast, http://www.aussiehomebrewer.com/forum//ind...40622&st=20 I posted here about an experiment that was done to show evolution in e.coli bacterium (very interesting IMO) and well worth a read.

Aaron

edit; grammar and spelling

 

[tommygun]

Im a horticulturist and have been involved with a bit of plant breeding. When you've gone through the long process of cross pollination with the compatible species you then have to trial sometimes many hundreds to thousands to come up with a usable hybrid or two.

I'm not saying that its the same methods and results but I'm sure if you want good results many, many trials would need to take place to end in results which may only at best be satisfactory.

But it is a good thought trialing different yeast working together in harmony to produce something different possibly even using different yeast at different stages of fermentation by filtering and repitching.

:icon_cheers:

thomas

 

[pdilley]

Nick, it depends on how much of a lab you want to build yourself at home but its not going to be easy with yeast. Easier to develop strains with mushrooms and dikaryotic fungi with haploid and diploid states. You can smear spores on petri dishes and look where two haploid cells join their chromosomes into a single diploid cell. These points then are visible to the naked eye in the petri dish taking off in mad large ropey rungs of growth. You cut out and transfer these to new petris and you develop pure strains that way contintinually cutting and transferring.

Yeast also has a haplophase where two types of haploid cells are formed each containing 16 chromosomes. When mated to an opposite haploid cell they form diploid cells which contain 32 chromosomes. The thing is with yeast all haploid and diploid cells can reproduce through asexual budding. This compounds the ability to easily isolate pure strains. Instead you have to employ dna analysis slides to compare. Much too much mucking around imho. Oh and the lager yeasts are the wierdos of the bunch with 64 chromosomes in them. Mutants that they are!

I have no studied yeast reproduction enough to even venture what would be needed to build your lab at home or if its possible. I can pretty much send you to Bunnings to get bits to make a mushroom strain isolation home lab. But alas today you can now walk into any supermarket and get a variety of fresh what were once exotic mushrooms easily.

EDIT: And nutrient deprivation is what is said to cause sporulation in yeast. As they switch to a mode to promote long term survival in the outside hostile world waiting for more hospitable environments to re-emerge.

Cheers,
Brewer Pete

 

[jonocarroll]

EDIT: And nutrient deprivation is what is said to cause sporulation in yeast. As they switch to a mode to promote long term survival in the outside hostile world waiting for more hospitable environments to re-emerge.

In the link I added, they suggest V8 is an ideal, nutrient deprived environment... and they want us to drink that stuff?

 

[manticle]

. But alas today you can now walk into any supermarket and get a variety of fresh what were once exotic mushrooms easily.

The day you can get portobellos, white and black truffles and even decent shitakes at my local supermarket, I'll be a happy man.

Can get most of the above at fresh food markets at various points but the expense compared to being able to grow your own would be........................

 

[Weizguy]

Nice work Brewer Pete. I am actually a qualified Biologist (otherwise employed).
I would say that the breeding and culture of brewing yeast is too difficult for your average home brewer.
How are you going to test all these yeasts once you have created and isolated and cultured them up to working strength?
A series of identical small brews from a single large batch, stored in separate 1-5 litre conicals in an isolated fridge?
How do you plan to test them? Double blind tests with a professional tasting panel?
It gets bigger and better and much more complex.

Frankly, I like the way this thread was going, with the multi-strain pitches.

Last year I planned to give a friend at work some Bavarian wheat yeast to pitch into a wheat beer. A couple of days before supplying it to him, I pitched into a fresh starter, realising that I had pitched Rogue Pacman, so I topped it up with the Bavarian wheat and told him that he would get a hybrid beer. I assumed similar results to the Wyeast Bavarian Wheat blend (American ale and Weihenstephan wheat yeasts), but with different, but still similar strains. The beer was one of the best wheat beers I have tasted, homebrew or otherwise.

 

[Muggus]

Last year I planned to give a friend at work some Bavarian wheat yeast to pitch into a wheat beer. A couple of days before supplying it to him, I pitched into a fresh starter, realising that I had pitched Rogue Pacman, so I topped it up with the Bavarian wheat and told him that he would get a hybrid beer. I assumed similar results to the Wyeast Bavarian Wheat blend (American ale and Weihenstephan wheat yeasts), but with different, but still similar strains. The beer was one of the best wheat beers I have tasted, homebrew or otherwise.

After trying quite a number of Rogue beers, i'm intrigued to know what strain Pacman is?
They seem to use it to great effect in a number of beers and they're all very clean, fermentation wise.

Sorry :icon_offtopic:

 

[geoff_tewierik]

IIRC it's their own strain.

One that's more than likely a standard strain that they've subjected to their own environmental regime and it now works at the temps they require and throws off the right byproducts.

 

[pdilley]

The day you can get portobellos, white and black truffles and even decent shitakes at my local supermarket, I'll be a happy man.

Can get most of the above at fresh food markets at various points but the expense compared to being able to grow your own would be........................

EDIT: :icon_offtopic:

Well you are partially in luck, except for black truffles and I got out before studying white, you are talking to an old hat in mushroom growing, and not just the ones teenagers are interested, proper gormet and medicinal ones.

Agaricus bisporus (Portobello) - surprise its just white mushroom thats aged and browned (Swiss brown, Portobello) feeling ripped off by the Supermarkets yet

Lentinula edodes (Shiitake) - easy to grow on sawdust substrate blocks.

Its easy to even clone mushrooms by extracting mycelium from the core and transferring to a petri dish. You get a perfect clone but you are further down the generation of cells so closer to mutation but its an easy way to use fresh markets as your culture library.

These I can teach you to grow but you will have a bit of study ahead of you and some gear buildup. Mostly petri plates, jars, pressure canner, and either old-school (glove box) or new-school Hepa-filter laminar flow hood or flow wall, scapels, innoculation loops. I have all my old agar recipes one even crossover from brewing using dry malt extract

If I was in QLD I'd probably give the old Volvariella volvacea (Paddy Straw Mushroom) a go as I'd love to find it fresh in its egg-form so I could inject tamari sauce (natural fermented soy sauce) in it and roast em then in the mouth for a flavour explosion :icon_drool2:

Even though its a bit of a study and even more so clean-sterile environment at a few critical steps only in the process it will be a hell of a lot easier than trying to work with creating yeast strains.


Cheers,
Brewer Pete

 

[manticle]

EDIT: :icon_offtopic:

Well you are partially in luck, except for black truffles and I got out before studying white, you are talking to an old hat in mushroom growing, and not just the ones teenagers are interested, proper gormet and medicinal ones.

Agaricus bisporus (Portobello) - surprise its just white mushroom thats aged and browned (Swiss brown, Portobello) feeling ripped off by the Supermarkets yet

Lentinula edodes (Shiitake) - easy to grow on sawdust substrate blocks.

Its easy to even clone mushrooms by extracting mycelium from the core and transferring to a petri dish. You get a perfect clone but you are further down the generation of cells so closer to mutation but its an easy way to use fresh markets as your culture library.

These I can teach you to grow but you will have a bit of study ahead of you and some gear buildup. Mostly petri plates, jars, pressure canner, and either old-school (glove box) or new-school Hepa-filter laminar flow hood or flow wall, scapels, innoculation loops. I have all my old agar recipes one even crossover from brewing using dry malt extract

If I was in QLD I'd probably give the old Volvariella volvacea (Paddy Straw Mushroom) a go as I'd love to find it fresh in its egg-form so I could inject tamari sauce (natural fermented soy sauce) in it and roast em then in the mouth for a flavour explosion :icon_drool2:

Even though its a bit of a study and even more so clean-sterile environment at a few critical steps only in the process it will be a hell of a lot easier than trying to work with creating yeast strains.


Cheers,
Brewer Pete

Totally off topic but what can you do?

Sorry I meant to type Porcini, not portobello. I did know that swiss brown and regular mushrooms were the same and hence never buy any SB. I usually go for field mushrooms as they have more flavour than buttons and are often cheaper (and yes I know they are the same species at different growth/harvest points too).

I wouldn't mind getting into a bit of edible mushroom growing - I have gathered and eaten fresh mushrooms (plain garden variety) and the flavour you can get from a naturally occuring one is tremendous.

I'll pick your brain on cider mead braggot jao sake mushrooms bread at a later point.

 

[pdilley]

Porcini's are a symbiotic fungus, so you'll have to plant some conifer trees first and do some soil amendments. A long term project for sure

EDIT: I can do about 42 different types of mushrooms, most you may have not heard of. I was originally going to move back and settle in QLD and do some mushroom farming but then I noticed you have a decent selection already in the markets but there are a lot I don't see but the capital is drier than a nun's n*****

Cheers,
Brewer Pete

 

[Darren]

I have a laminar flow at a good price if anyone is interested?

cheers

Darren

 

[bum]

IIRC it's their own strain.

Wyeast were selling Pacman as 1764 for a while. Dunno how hard it is to get a hold of now.

 

[altstart]

Interesting and informative thread and it demonstrates what a valuable brewing resource this forum is.

Cheers Altstart

 

[benny_bjc]

out of interest...

If you were making a really high alcohol beer with lots of malt - could you add a mixture of wine and ale yeasts to achieve the higher alcohol content but retain some of the characteristics of a particular ale yeast?

If so would you mix them both at start of fermentation or would you add the ale yeast in primary then transfer off the yeast to secondary fermenter and add wine yeast?

Thanks