Looking For Answers to Q's regarding yeast collection exploits

[boiseburb]

This past month a microbiologist friend and I were working on collecting wild yeast. We pulled samples from juniper berries, plums from my tree, and from the wild.

We set up multiple petrie dishes using plum and juniper yeast samples, along with corn sugar and malt extract as food sources. In mason jars, we set up malt extract and hops. One each of juniper berries, plum, and wild.

With the jars, I decided to transfer some of the liquid after two weeks from the wild and plum jars. I pulled the liquid from close to the bottom, avoiding the top layer of film. When we checked the samples under the microscope for sacc., there was Nada, nothing.

Question 1: Where is the best place to grab a sample of sacc to transfer to another jar of malt extract? What should I be looking for?


With the petrie dishes, we sort of messed up and forgot to put the second strike dishes into the fridge. They were at room temp for about a week. The two samples sans mold were from the juniper berries. One eating corn sugar, the other malt extract. We were able to view good colonies of sacc. under the microscope. We put samples of those into jars of malt extract and hops and let them sit at room temp. It's been 30 hours and I have yet to see any action.

Question 2: Should I be worried about the progress? Is there something I should do to help the yeast eat and grow? Any other thoughts?

Any help or suggestions would be appreciated

 

[passedpawn]

Q1: Just swab a bunch of berries and vegatation and transfer to your plates, then grab colonies that look like sac and tranfer to new plates. Try to isolate colonies growing from single cells. Make a starter from this and smell it. You'll know if it's OK or not pretty quick.

Q2: Nope, yeast + wort + aeration should do it. You could add some yeast nutrients (zinc), but it's not necessary at all.

I'm doing some of this myself these days. Good luck.

 

[ReverseApacheMaster]

Were you just checking the liquid or was there any material at the bottom you could have checked? In those small amounts of extract, there's not much sugar and everything in your sample is fighting for it. If the fermentable sugars were all consumed, the sacc would have drifted to the bottom with nothing left to eat.

 

[boiseburb]

Were you just checking the liquid or was there any material at the bottom you could have checked? In those small amounts of extract, there's not much sugar and everything in your sample is fighting for it. If the fermentable sugars were all consumed, the sacc would have drifted to the bottom with nothing left to eat.

I had trouble getting all the way down to the bottom of the jar. I'm thinking that was the problem. Would any sacc be at the top at all?

 

[boiseburb]

Q2: Nope, yeast + wort + aeration should do it. You could add some yeast nutrients (zinc), but it's not necessary at all...

My main concern right now is aeration. How long should I wait before I should work on aerating, and what would be the best method?

 

[passedpawn]

My main concern right now is aeration. How long should I wait before I should work on aerating, and what would be the best method?

Best = stir plate, w/ loose foil or open-cell foam stopper on the top of the flask.

Shaking is OK too.

 

[boiseburb]

Still no action. Do you think density could be an issue? It is pretty thick with malt extract and hops?

 

[ReverseApacheMaster]

I had trouble getting all the way down to the bottom of the jar. I'm thinking that was the problem. Would any sacc be at the top at all?

If you only have a few cells, at least relative to everything in there, you might miss it just grabbing off the top.