Yeast Slant Problems

[jzani]

Have been browsing for some info on this problem but can't find anything specific.

I have just started making some yeast slants to save a few pennies on the good quality yeast, but the only Test Tubes I could get my hands on have rubber bungs rather than screw on lids.

I made the slants (gelatin, 1040 LME & water) no problems (following these instructions- http://www.realbeer.com/spencer/yeast-culturing.html), left them for a while to make sure they were sterile, then inoculated with 1084. I left them at ambient (up to about 21^oC) and on day two I came home to find the lids had popped off three of the four inoculated slants .

I stuck the lids back on (with tape this time) and they have been growing nicely for the past couple of days. I figure if nothing fuzzy grows in the slants they should be fine, and I can double check when making a starter anyway.

A bit of advice from the more experienced, though, is it worth taking the risk or are they mare than likely to be infected?

I'm thinking next time I should probably start the slants with a glad wrap lid and only put the bungs in when I tape them up and fridge them.

Thoughts appreciated.

Juzzy

 

[barls]

i think ive still get some left over 50ml screwtop tubes left over from a bulk buy i did a while ago.
pm me if interested.

 

[raven19]

You want the lids on loosely while the slants grow otherwise the CO2 produced wont be able to escape.

As such screw top test tubes as they can be put on loosely during the slant growth stage.

If the tops came off of some, I would ditch these - your Slant should be as free from outside influences as possible.

Not saying these popped ones are infected but I would not risk it personally.

Loosen the other slants and only tape them up after growth has finished.

I don't tape mine till they get put into the fridge.