Renewing The Yeast Cultures

[Zwickel]

no worries mate,

thats what this forum is created for, just to spread the knowledge.

Can you imagine, that a certain amount of harvested yeast containes not only living yeast cells?
It is simply not possible by washing the yeast to separate the dead or degenerated yeast cells from the good and healthy one, nor is it possible to separate floating debris that is at the same size and weight like the yeast cells. The only thing you can do whilst washing is to dilute the liquid and lower its alcohol content.

So in the end youll get all that unwanted stuff into your starter and later into your beer.
If there are any strange germs in your yeast, they will multiply over the time.

On an agar bottom, if youre going to revive one, youll only extract living yeast cells, all that unwanted stuff remains in the agar.

Cheers

 

[alexbrand]

Suffers how? Does it die or just go to sleep? Considering the effort you go to to make a starter from an agar slant, I'm thinking if it only goes to sleep, it's easier to just keep a jar of washed yeast in the fridge and pitch the whole jar to start a new brew. Then collect the trub, wash and keep THAT in the fridge. Less (or same) work, less cost and presuming you don't need to do two brews with the same yeast at the same time, endless supply.

Zwickel already answered the question, nothing to add.

I have no idea who postulated the theory, a home brewer can wash yeast. Well, I mean, of course one can wash yeast. But with rather no effect. It might be possible to seperate cells from other rubbish. But not cells from cells. Doesn't matter if it's yeast, bacteria, virus, prions or what ever.

Happy yeast farming!

Alex

 

[mikelinz]

One of the links on slanting said to let the medium dry out as moisture in the slant can lead to mold etc. So How do I dry it out if it is sealed.

 

[mikelinz]

Is there a list where you can post yeast types/slants you have available for swap etc

rgds mike

 

[Zwickel]

One of the links on slanting said to let the medium dry out as moisture in the slant can lead to mold etc. So How do I dry it out if it is sealed.

how mould can grow if everything is steril?

If you got mould spores into the slants, the mold will grow whether the agar is wet or dry, other hand, If everything is steril, no mould can grow.

Since Im doing yeast farming I had almost every form of agar, from very wet to very dry, neither of them ever had any mould in.

Anyway its recommended to keep the agar as dry as possible, one procedure could be:

sterilize the vessels in a baking oven (without the cap). Fill in the hot agar at around 100C and leave it in the baking oven. Slowly cool down and do a rest at around 40C. after a half an hour open the baking oven and cap the vessels. voil thats it.

Cheers :icon_cheers:

 

[Zwickel]

Is there a list where you can post yeast types/slants you have available for swap etc

rgds mike

Mike, much to my regret, Im not living in Australia, otherwise Id like to give away many of my yeast strains.
But as more and more homebrewers get into yeastfarming, maybe one can organize a swap meet or do an exchange via mail.

Cheers

 

[Sprungmonkey]

Zwickel - Im in

 

[quadbox]

Here's my first effort, so far:

Those lids are only on loosely atm to let the moisture dry out a bit before I seal them. Planning to leave them for a week or so to check for infection, then inocculate 10 with wlp-001, 10 with wlp-023, and five with wlp-002

 

[Duff]

Well done, they look good. No need to leave for a week to check infections, 2 - 3 days at room temperatures will suffice.

Cheers.

 

[remi]

Looks the goods....fun isn't it?

remi

 

[Sprungmonkey]

I used one of my first slants yesterday (after preparing a starter friday last week). Used a whitelabs mexican lager. Also made some San fransico lager ones as well. The cervasa is bubbling like crazy so it appears to have worked. Looking forward to the end results.

 

[Sprungmonkey]

If the final results are all good I don't think Ill ever used dried yeast again

 

[quadbox]

If the final results are all good I don't think Ill ever used dried yeast again

Well I mean just from a price point of view, you're looking at like 80c worth of dme for a 1L starter, perhaps another 80c worth of slant, vs $4 or more per sachet of saf. That works out to be a fair saving over time imo, especially given you can keep cultures of a wide variety of yeast

 

[Sprungmonkey]

I didn't use as stirrer at all with the starter but stirred it evey time I walked past. I think Ill get one of those next.

 

[Zwickel]

wow, that looks very nice

well done mate. :icon_cheers:

 

[Sprungmonkey]

wow, that looks very nice

well done mate. :icon_cheers:

Thanks for your help

 

[tynian]

Thanks to this thread, I made my first slants on the weekend. It just seemed all to easy.

I am going to do some Wyeast 2001 (Urquell) this weekend. Then I hope to move some of my 3944 to slants for safe keeping.

It would be great if there are any other peoples interested in doing swaps etc.

Rob.

 

[Steve Lacey]

1) Why are all you people wasting a whole slant each time you brew? Just use a sterilized (flame or alcohol) loop or needle or whatever to pull out a blob of yeast from the slant and step up a starter going: 20 mL ... 200 mL .... 2000 mL (or less). And your slant will be good to use again tomorrow, next week or next year (conditional to the answer in part 2). The photos with rows and rows of slants seems unnecessary unless the user is about to culture up a dozen or so different strains. You should never need more than three slants of any variety, and even then two of them are reserves.

2)

Some of the links posted in this thread suggest 3 months! Then you have to "renew" the yeast. But some of the posts in the thread suggest up to a year!

The thing about yeast is that it is a living organism and there are all kinds of variations that affect the answer to "how long can I keep a slant?" Differences between strains, differences in the quality of the medium, differences in your level of sterility. So mentions of "three months" means in most cases you should be very safe for up to three months. After that, you could be fine for another 12 months or 2 years or more if you look after the thing. But the certainty of it all being good just gradually declines, so at some point to get yourself back into safe territory you make some new slants and innoculate them with a tiny dab of yeast from one of the old slants, provided the yeast still looks clean.

 

[~MikE]

Thanks to this thread, I made my first slants on the weekend. It just seemed all to easy.

I am going to do some Wyeast 2001 (Urquell) this weekend. Then I hope to move some of my 3944 to slants for safe keeping.

It would be great if there are any other peoples interested in doing swaps etc.

Rob.

should we perhaps set up a AHB wiki page where people post up their stocks of yeats. then we could just PM trade via mail etc

but yeah, i'm definitly up for it.

 

[AndrewQLD]

1) Why are all you people wasting a whole slant each time you brew? Just use a sterilized (flame or alcohol) loop or needle or whatever to pull out a blob of yeast from the slant and step up a starter going: 20 mL ... 200 mL .... 2000 mL (or less). And your slant will be good to use again tomorrow, next week or next year (conditional to the answer in part 2). The photos with rows and rows of slants seems unnecessary unless the user is about to culture up a dozen or so different strains. You should never need more than three slants of any variety, and even then two of them are reserves.

Steve, I think the idea behind this thread is to be able to use the whole vial as a starter, Zwickel posted his method early in the thread and Chiller added a more complete description which included his system of adding boiled cooled wort to the inocculated vial, shaking and leaving overnight to create a mini starter of sorts. This is then pitched into a larger sized starter ect.

Andrew