Is it possible to store a little of each yeast in a sanitised vial in the fridge until I get the equipment necessary to start making slants?
If so how much would you save in each vial?
Would you save the yeast directly from the Vial/Smack Pack or would you save it from the starter?
How long do I have for the yeast to remain healthy in the fridge before I would need to slant?
I had a tube of WLP830 I wanted to slant, but didn't have any slants ready yet. My solution was to not pitch the entire tub into my starter. I saved back about an 1/8th of the vial. I assume it will be good as long as the expiration date on vial.
I thought this would be better than grabing a sample from a starter because the vial should be bacteria free when it was filled at White labs.
-TPM- said:The White Labs viles aren't any good, they melt a bit and turn white so you can't see through them anymore.
-TPM- said:NP. If you want a cheap source let me know and I'll pm you the site where I got mine (~50c each)
Awesome tutorial, and thanks for the idea. Here are my slants.
For those of you who don't have all the equipment ready to do this, I highly suggest you bribe someone who has access to a microbiology lab to do it for you. I did this at my workplace (on lunch, of course!) and it was a snap.
Regarding this protocol, wouldn't it be better to use a high proof alcohol, e.g. Everclear, instead of sanitizer? That's what I've done in the lab. Dip the loop, aka paper clip, into the Everclear, flame, and then wave back and forth to cool.
70% alcohol is considered the best percentage for sanitation. Everclean is 90% so it needs to be diluted
Another thought, if you had access to sterile tubes/plates, could you just pressure cook a bottle containing all of your agar agar to sterilize and then pour plates or pour into tubes? I'm guessing that tubes would be better for long term storage than plates in the fridge; you wouldn't want your fridge smelling like yeast. I suppose that you could sterilize all of your empty tubes first, sterilize your agar agar separately, and then transfer. Food for thought.
I may have missed this, but do you store your un-innoculated slants in the fridge too, or at room temp somewhere?
My slants looked great after setting up, but have started to turn watery after a couple weeks. I used the proportions mentioned on the first page with pharmaceutical grade agar. Any suggestions??
RJSkypala said:
Whats the optimal temperature for storing the slants after incubation..I just got a mini fridge for my yeast and its sitting at about 33 F
33 is right where I try to keep mine. As close to freezing without freezing.
My slants looked great after setting up, but have started to turn watery after a couple weeks. I used the proportions mentioned on the first page with pharmaceutical grade agar. Any suggestions??
My recipe for slant media is:
1.5% agar powder
7% DME
1% Wyeast yeast nutrient
That is by weight so if you have, say, 500mL of water you will add 7.5 grams of agar and 35 grams of DME along with 5 grams of the nutrient.
The agar powder def. works better than the stuff I got at the grocery store, which after a few months in the fridge started falling apart.
As promised, here's a picture of the rack I used, available here:
http://www.cynmar.com/Staging/item_detail.aspx?ItemCode=15025994
It says it's only autoclaveable to 250*F, so I kept the pressure between 12 and 13 to make sure it didn't melt. (15 PSI is required to hit 250, so I figure that's a pretty safe margin.)
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