Volumetric flasks for storing yeast?

[MDRex]

I received a large number of volumetric flasks from my father in law. They range in size from 1ml to probably 50ml. The flasks have nice stoppers, but no threaded caps that would seal. I am thinking that they would be good to storing yeast taken from bottle dregs, and then using to make starters. Is this a good idea and what would be the best way to store them?

 

[nefarious_1_]

I think the flasks would be fine. I work in a lab and we use glass-on-glass connections all the time: they form a near perfect seal. In some cases, these connections are preferred over threaded closures. As far as volumetric flasks, we have several for water testing and all use stoppers. Frosted glass is made to create a seal.

 

[MDRex]

Great, I didn't know that about the stoppers. These were an awesome find, since they were going to be thrown away by a pharmaceutical company my father in law used to for. I also score some nice beakers, graduated cylinders from very small to huge, small El flasks, SS air stones and lots of pipets. He's still looking to see if he has any stir plates too.

Should I try to make slants with the flasks? Or is there something else/easier I can do to store yeast in them? I don't have a pressure cooker, which seemed an important part to making slants.

 

[MDRex]

I should add that one thing I'm really trying to do is capture wild yeast and bacteria from bottles of sour beers.

 

[SickTransitMundus]

I would be wary of using volumetrics to store yeast. They're not designed to handle internal pressure, nor will the stoppers stay in place if your sample offgasses.

If they are ground glass stoppers, they will eventually cold-weld into the flask neck unless you grease them.

They should be fine, however, for making starters.

 

[MDRex]

How long would it take for the stoppers to cold-weld to the flasks?

I would use them for starters, but they are way to small for that. Most are 50ml and smaller.

 

[SickTransitMundus]

I have just been informed by a colleague that ground glass sticking is not technically cold welding. They will eventually freeze nonetheless. I've seen it happen overnight, but typically it will take a few days.

 

[nefarious_1_]

Interesting... We keep one in all of our fridges with a little water to take temp. readings and it's not really an issue.
Good point about the offgassing though.