Yeast Farming

[olskoolsoulja]

English people.

I said inagar. my 9 grade science teacher told me(last year) that agar is like a sponge and the nutrient sits in all the little holes, agar is the best gelling agent and it comes from seaweed mostly from Japan. I hope you found somthing interesting there.

 

[pint of lager]

English people.

I said inagar. my 9 grade science teacher told me(last year) that agar is like a sponge and the nutrient sits in all the little holes, agar is the best gelling agent and it comes from seaweed mostly from Japan. I hope you found somthing interesting there.

Good to see you were paying attention in school.

You may have noticed that in good microbiological practice, any prepared petri dish or slant is sterilised. This means that any germs in or on the agar are destroyed. If there were any germs in the agar, there would certainly be some also on the surface which would render the plate useless. You may also have noticed that yeast work occurs on the surface of the agar, rather than in the agar. Have a read of the links posted earlier in this thread.

 

[Sprungmonkey]

Broth is a soup term that is not used in brewing. You are making wort and beer, not broth.

You are storing large samples in bottles/jars/test tubes under either water or beer.

You are storing small samples on either slants or petri dishes. The agar solution also includes malt as nutrient for the yeast.

Taste all your starters and fermenting worts. Different yeasts show different characteristics as they ferment. There is no firm taste test to say what is infected or wrong.

If you go the microscope path, you are going to need a good one, capable of 1,000x. Better to spend that money on a pressure cooker and some glassware.

Sorry pint of lager - couple of other questions.

Do you or anyone else use nutrients other than just malt (ie. minerals vitamins which aid to more efficient fermentation, etc).

The term broth is used a microlab I work close with and is used when describing any culture in solution but anyhow.

The cultured solution I was planning on trying out would be in test tubes with nutrient and peptone water.

I can run a test to see the difference between both methods (slant / cultured solution) and look at the viability of yeast cells as they move though the lag phase to the death phase. This should basically tell me which method would have the longest shelf life. Luckly I have acess to a micro lab and a work mate who is a microbiologist.

I do however tend to agree with using slant tubes with regards to being able to selectively choose "good" looking cultures growing on the surface.

One last thing on the tasting of starter culture prior to pitching - even though there is no defined contaminated / not contaminated indicator can you tell by the taste that, yes this is infected and therefore shouldn't use it. I guess what i am trying to say is that if i taste it will i know yup its infected or no it should be okay.

 

[pint of lager]

I use some Wyeast yeast propogation nutrient blend, just a small amount scaled from a starter wort back to the volume being used to make the agar medium. Also, malt extract is used, at the same ratio for a starter sg, 1.040 which is 100 gms DME per litre of water.

With regards to the term broth, have never seen it come up in the reading on yeast culturing. Obviously you find it a common term in relation to your microbiological knowledge.

One method with yeast storage is to maintain a small amount of yeast in sterile (not demineralised) water in the coldest part of the fridge. Have a read of Graham Sander's article on craftbrewer.org which outlines this method.

Many people do report being able to revive very old yeast samples, either from slants, commercial packs from Whitelabs and Wyeast and from yeast sediments in bottles. My concern about stretching this is that we are selecting the yeast on longetivity rather than its ability to brew a good beer. Each method does work, but once the yeast starts propogating, do we only have mutated cells. To test for this is going to take more than looking through a microscope. The general concensus is whatever method you use, revive the yeast every 6-12 months, reculture (or reslant) and then store back away.

Commercial yeast strain banks are kept frozen.

There is no known taste test that will definitively say, infected or not. What i do is to sterilise the starter wort for the first two steps (20ml and 200ml in erlenmeyer flasks in a pressure cooker) and do the transfers as aseptically as possible, minimising infections. The only way you can definitively say, no it is not infected is on the grown out agar plate, or by looking through a microscope at a sample of your wort. There are test kits for commercial breweries, but they will not confirm wild yeasts. Often a starter will taste funky, but that is due to fresh yeast byproducts.

Lucky you having access to a microbiological lab. Make sure your friend shows you how to prepare plates, streak them up and then examine them. Hopefully you end up with some good results and can tell us which method will work the best for long term storage in a homebrew environment.

 

[the_fuzz]

Ok,

I've been farming for a little bit, just harvesting the slurry from previous brews. Tomorrow I should have my first liquid yeast arriving in the mail (Wyeast 1056) and this is my plan:

I have about 10 sterialised 50ml vials
I was going to not smack the pack
Then I was going to open the pack and use a siringe to remove the yeast and break it up into the 10 vials - Approx 10ml of yeast per vial.
Then I was going to place sterile water on top and place into the fridge

When required, step up from the 10ml of yeast small and go from there

What is wrong with my plan? Can liquid yeast go straight under sterile water? Or is this somehow harmful?

Cheers
Mick

 

[Sprungmonkey]

Ok,

I've been farming for a little bit, just harvesting the slurry from previous brews. Tomorrow I should have my first liquid yeast arriving in the mail (Wyeast 1056) and this is my plan:

I have about 10 sterialised 50ml vials
I was going to not smack the pack
Then I was going to open the pack and use a siringe to remove the yeast and break it up into the 10 vials - Approx 10ml of yeast per vial.
Then I was going to place sterile water on top and place into the fridge

When required, step up from the 10ml of yeast small and go from there

What is wrong with my plan? Can liquid yeast go straight under sterile water? Or is this somehow harmful?

Cheers
Mick

I don't see any major issues but why would you put water on top. If it was me and I was dividing up yeast that way, I would just divide them and leave them. You should try culturing onto agar slants. It not too hard and yeast will last longer.

 

[Cortez The Killer]

Found an interesting article on yeast handling methods and laboratory methods

Haven't seen it posted here before

It's quite interesting with respect to sterilisation when using slants or dishes

http://www.phys.ksu.edu/gene/g1.html

Cheers

 

[the_fuzz]

I don't see any major issues but why would you put water on top. If it was me and I was dividing up yeast that way, I would just divide them and leave them. You should try culturing onto agar slants. It not too hard and yeast will last longer.

I would have thought it would stop expose to air that is stuck in the vial - just like when you farm slurry - you put sterile water ontop of the yeast?

Or is the water not required?

 

[Trough Lolly]

Interesting -- not too sure. Slant to slant, inoculation broth to inoculation broth, tomato tomato. Don't know if there is any difference in generations and possible mutations. Activity of the yeast should be limited purely due to refigeration storage. I can however see your point regarding nutrient availability on slants. I don't know how critical it is at refrigeration temps. I might have to try both and look at the viability of yeasts slant vs broth.

G'day Sprungmonkey,
The other point that's worth considering is what do you want to do with the yeast? Do you need readily accessible yeast that can innoculate the wort same day, or a bank of yeast cultures that you can make starters from before brewday? Chiller and PoL have given you plenty of info and there's no need to get into slants or plating out cells on agar if you need a short term storage solution for your yeast (eg, sterile jars with washed slurry). I have a number of strains that I regularly use and inevitably they're stored as slurry in 600ml PET bottles ready to go in a few hours.

Chiller - concur with your thoughts earlier re the viability of certain strains that are 2+ years old. I too have observed plenty of good ferments with old 1056 / 1084 / 1028 / 1968 etc but when I build up elderly starters of lager strains eg Wyeast 2000 / 2124 / 2633, they can be something of a lottery despite good aeseptic protocols and accurate temperature control!

Cheers,
TL

 

[braufrau]

germs cant grow in agar

OK ... not in but on ... here's lots of germs growing on agar ... http://en.wikipedia.org/wiki/Agar_plate

 

[Sprungmonkey]

G'day Sprungmonkey,
The other point that's worth considering is what do you want to do with the yeast? Do you need readily accessible yeast that can innoculate the wort same day, or a bank of yeast cultures that you can make starters from before brewday? Chiller and PoL have given you plenty of info and there's no need to get into slants or plating out cells on agar if you need a short term storage solution for your yeast (eg, sterile jars with washed slurry). I have a number of strains that I regularly use and inevitably they're stored as slurry in 600ml PET bottles ready to go in a few hours.

Chiller - concur with your thoughts earlier re the viability of certain strains that are 2+ years old. I too have observed plenty of good ferments with old 1056 / 1084 / 1028 / 1968 etc but when I build up elderly starters of lager strains eg Wyeast 2000 / 2124 / 2633, they can be something of a lottery despite good aeseptic protocols and accurate temperature control!

Cheers,
TL

Cheers TL I am trying to build up a bank of yeasts and therefore make starters prior to using. This will eventually allow me to pick and choose as to which yeast I want to use.

 

[Sprungmonkey]

Anyone tried to put coopers yeast from a bottle onto a slant for later use. Also is the yeast for pale ale and sparkling ale the same?

 

[BoilerBoy]

Anyone tried to put coopers yeast from a bottle onto a slant for later use. Also is the yeast for pale ale and sparkling ale the same?

The yeast is the same, but I wouldn't see any point storing it on slants as its readily available, even a single stubbie is all thats needed to culture the yeast if your patient

Cheers,
BB

 

[Gavo]

Hi, I would just like to thank "chiller" for his info on yeast farming. I am new to doing anything other than straight K&K and would never have thought I could reuse yeast and therefore would have allways thought again before buying a specialty yeast. So I decided to give it a go with SafAle 05 yeast and found that I was a easy process, although I think I lost some yeast as I left the last change to long and some of the yeast had settled before I poured it off.
I then proceeded to make my first yeast starter from one of the small bottles and the brew has started quite well , I used some small jam bottles as they were all I have at present. Anyway I have uploaded some photos of my results. I haven't quite finised cleaning the yeast yet so the water is still slightly cloudy.
View attachment 20578View attachment 20579

 

[~MikE]

Anyone tried to put coopers yeast from a bottle onto a slant for later use. Also is the yeast for pale ale and sparkling ale the same?

yeah, i've got a slant of it right now. i find it recovers much quicker than it does from a bottle.

one thing to remember, make two starters - one say 50ml recovery and up it into another larger - say 500ml to buld up the cells. underpitching with coopers is not pleasant and going straight into a 500ml will create some not too pleasant aromas.

 

[Fourstar]

So I decided to give it a go with SafAle 05 yeast and found that I was a easy process

yest farming is best to be done on liquid yeast. Purely for the effort involved and the cost of the yeast. For the time you spend washing a saf 05, putting to slants and storing you could have saved more on time buy purchasing another $4 packet. Ive been told Dry yeast doesnt hold up that well with multipule generations .

The only thing worthwhile with dry yeast is harvesting some leftover slurry or pitching directly onto the cake.

For practise i guess its worth the time. better to stuff up a $4 safale than a $15 wyeast!



Edit: removed attachments from quote

 

[Thirsty Boy]

Just posted my yeast library in the Yeast Slant Register.

I'm looking to get myself some of Wyeast 3724 Belgian Saison if anyone is interested in a swap with one of the yeasts I have.

Shoot me a PM if you are interested

Cheers

TB

 

[Quintrex]

Just posted my yeast library in the Yeast Slant Register.

I'm looking to get myself some of Wyeast 3724 Belgian Saison if anyone is interested in a swap with one of the yeasts I have.

Shoot me a PM if you are interested

Cheers

TB

Too bad thirsty I gave awaay a ton of slurry at the last vic case swap. I might fire another one up soon though if your interested. One of my champagne bottles of saison shot its cork out in the heat yesterday :-(

 

[therook]

Too bad thirsty I gave awaay a ton of slurry at the last vic case swap. I might fire another one up soon though if your interested. One of my champagne bottles of saison shot its cork out in the heat yesterday :-(

I think there is 2 still left in the fridge at home, i can check and see if you want one TB

Rook

 

[reg]

I have one from the Vic case swap if you want it TB

I Live in Werribee if you want to pick up.

Cheers
Reg