Condensation problems on slants and plates - Home Brew Forums
Home Brew Forums > Home Brewing Beer > Fermentation & Yeast > Condensation problems on slants and plates

Reply
 
Thread Tools
Old 06-18-2010, 02:44 PM   #1
Budzu
Recipes 
 
Mar 2009
Chattanooga, TN
Posts: 747
Liked 17 Times on 16 Posts



I would love to hear from someone with experience in this.. I have been keeping yeasts on slants and plates for several months now but I have a new developing problem that I do not know the reason for.
All the batches of plates and slants I have made recently have way too much condensation on them. In the case of my plates, I am waiting for the agar to solidify after autoclaving, then I am storing them upside down in the fridge in plastic bags. When I go to use some plates, there is always now water on the MEDIA side of the plate. If I try to streak it, the yeast just gets all wet and doesn't create tight colonies.

In the case of my slants, there is enough water in them that once I streak them, the yeast is traveling down underneath the slant via the water, and causing the entire agar bulk in the slant to slide up and out of the vial because of co2 pressure.

What the heck am I doing wrong? I can't figure out what is different now from when i was having so much success.

How do you deal with condensation issues on your agar media? Is refrigeration causing this?

Thanks in advance


__________________
Countertop Brutus Budzu-style

 
Reply With Quote
Old 09-21-2010, 01:08 AM   #2
Budzu
Recipes 
 
Mar 2009
Chattanooga, TN
Posts: 747
Liked 17 Times on 16 Posts


Thought I'd update in case anyone else encounters this issue.

Drying the slants longer did not solve the issue. The moisture will not evaporate from UNDER the agar media. Some I had dried for 2 days still developed the annoying lift.
I solved the slant lift problem by not covering the entire bottom of the slant.
This involved using slightly less agar wort and slanting steeper.

Solved the plate issue in this way:
Freshly cool out of the pressure cooker, I invert them media side up stacked in cardboard boxes. Overnight in an air conditioned house dried up every drop of condensation. Pretty simple. Before, I was paranoid and wanted to stick them in sealed bags right away. that was my mistake.

Good luck all!


__________________
Countertop Brutus Budzu-style

 
Reply With Quote
Old 09-21-2010, 12:23 PM   #3
JohnMc
Recipes 
 
May 2010
NC
Posts: 265
Liked 4 Times on 4 Posts


Budzu, when I pour plates in the lab, I let 'em sit on the bench for a couple of days before wrapping them, that does the trick. I just look at them once or twice a day.

 
Reply With Quote
Old 09-22-2010, 04:00 AM   #4
musick
Recipes 
 
Jun 2010
Ca
Posts: 100
Liked 2 Times on 1 Posts


Quote:
Originally Posted by JohnMc View Post
Budzu, when I pour plates in the lab...
...I have been known to place a bottle (or something that completely covers the diameter of the plate) full of very hot H20 on the top of the stack of petri dishes until the agar solidifies. This eliminates condensation in those top 2 or 4 plates. No condensation should be present in the middle plates, at least in my experience.

Storing poured plates cold encased in plastic will lead to moisture most of the time. Try parafilm instead, or keep at room temp. RT will allow any contaminants to make their presence known before you streak on them.

Reason: You got the inverted storage method

 
Reply With Quote
Old 09-22-2010, 11:49 PM   #5
Budzu
Recipes 
 
Mar 2009
Chattanooga, TN
Posts: 747
Liked 17 Times on 16 Posts


Quote:
Originally Posted by musick View Post
Try parafilm instead, or keep at room temp. RT will allow any contaminants to make their presence known before you streak on them.
Good point about room temp... never thought of it that way. Thanks for all the advice
__________________
Countertop Brutus Budzu-style

 
Reply With Quote
Old 09-24-2010, 12:26 PM   #6
JohnMc
Recipes 
 
May 2010
NC
Posts: 265
Liked 4 Times on 4 Posts


Quote:
or keep at room temp. RT will allow any contaminants to make their presence known before you streak on them.
+1
That's why I keep all my liquid media at RT; if I screw up, I know it next AM!



 
Reply With Quote
Reply
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Do My Slants Look OK? DKershner Fermentation & Yeast 11 02-19-2010 08:30 PM
Cleaning Used Slants TimWeber Fermentation & Yeast 2 01-12-2010 12:59 PM
Do slants only last 3 months? jmp138 Fermentation & Yeast 2 10-16-2009 02:42 AM
yeast slants subwyking General Techniques 10 03-25-2006 04:30 PM


Forum Jump