Author Topic: Yeast culturing queries.  (Read 1099 times)

Offline enso

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Yeast culturing queries.
« on: January 29, 2010, 12:46:37 PM »
I am just getting started with this and I have done a lot of reading on various web pages about culturing for and by homebrewers.  I think I have a fair idea of what to do, hands on is the best way to learn though...

I do have a few things I am unclear on.  The first is the goal of preparing slants.  I understand that streaking plates is to isolate singular colonies.  Slants seem to be more for storage?  Why are slants better for storage?  What is the goal of a properly prepared slant?  What should it be like?  I have read about people refering to a "lawn of yeast".  Does this mean your aim is to completely cover the top surface of the agar in the slant with yeast?  How does one go about this?  Meaning, if you apply yeast to the plate with the aim of having the least amount of cells, how do you achieve maximum coverage when aplying to the slant.

Not sure if my questions are clear or not, but hopefully with a bit of discussion we can clear my fog.   :D
Dave Brush

Offline Kaiser

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Re: Yeast culturing queries.
« Reply #1 on: January 29, 2010, 12:58:41 PM »
Slants are great medium length storage (up to 6 months) since the have a much smaller opening and thus easier to keep from getting contaminated or dried out.

To innoculate them just pick a colony with the loop and spread it around. Cover a lot of the surface but don't get anal about it. Zig-zag over the slant is sufficient. Then let it grow at room temp before storing at 2-4c. I don't go lower due to the risk of accidental freezing.

Kai

Offline Thirsty_Monk

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Re: Yeast culturing queries.
« Reply #2 on: January 29, 2010, 02:27:25 PM »
You could read about my adventure in Yeast Culturing in here:
http://www.homebrewersassociation.org/forum/index.php?topic=901.0

There are some pictures too as well as recipe for solid media.

"lawn of yeast" is continues streak where you can not isolate yeast colonies.
You try to streak for individual colonies and you do not want to have lawn.
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Offline roffenburger

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Re: Yeast culturing queries.
« Reply #3 on: January 29, 2010, 03:21:41 PM »
Here is what I do for slants.

Pick up some yeast with a loop, go all the way to the bottom of the slant and pull straight up. Then, go back to the bottom and zigzag across your first "pull."
A quick paint file...
Travis R.

Offline enso

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Re: Yeast culturing queries.
« Reply #4 on: January 29, 2010, 04:01:37 PM »
cool.  Thank you folks.   ;D

Just unpacked my order!  Cynmar is great.  The order came really fast!  I placed it earlier this week.  I am STILL waiting on an order I placed with More Beer (including some overpriced yeast culturing supplies!) over a month ago...   :'(

I can't wait to get started.  I am going to try the sterile distilled water storage method in addition to agar slants.  It is good to know the options.
Dave Brush

Offline Thirsty_Monk

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Re: Yeast culturing queries.
« Reply #5 on: January 29, 2010, 07:11:31 PM »
I am going to try the sterile distilled water storage method in addition to agar slants.

There was a recommendation to add little amount of salt into sterile water for better yeast viability.
Sorry I can not find it right now.
I think I have found it somewhere here:
http://micrap.selfip.com:81/yeastmanage.html
Na Zdravie

On Tap At The TapRoom:
Bohemian Pilsner
Bohemian Dark Lager
Smoked Bock
MaiBock
American Brown Ale
Marzen
Root beer

Offline enso

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Re: Yeast culturing queries.
« Reply #6 on: January 31, 2010, 03:53:11 PM »
I am going to try the sterile distilled water storage method in addition to agar slants.

There was a recommendation to add little amount of salt into sterile water for better yeast viability.
Sorry I can not find it right now.
I think I have found it somewhere here:
http://micrap.selfip.com:81/yeastmanage.html


Excellent!  Thanks T_M!  I think I found it.  Lots of great links there.
Dave Brush

Offline enso

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Re: Yeast culturing queries.
« Reply #7 on: January 31, 2010, 06:14:51 PM »
Looks like the salt to use is Potassium dihydrogen phosphate.  Not sure where to get my hands on that...  ???

Cynmar does not have it.  From what the article I read says it only adds to the viability it is not crucial to the survival of the yeast.  So for the mean time, until I can source some KH2PO4 I will try the plain sterile distilled water.
Dave Brush