OK to slant?

[Trail]

Due to a lack of foresight on my behalf, I bottled today but won't have glycerin for freezing the yeast for four days.

It's a limited edition yeast that's no longer available since I pitched, so I decided to gamble... boiled a 6oz mason jar for ten minutes, let the water inside cool, and poured the water on the cake. Then I swirled it to liquify the cake and poured it back into the mason jar until it was overflowing, capped, and star-san'd the outside of the jar.

Am I good to slant this yeast when my glycerin arrives?

 

[jordanmills]

Due to a lack of foresight on my behalf, I bottled today but won't have glycerin for freezing the yeast for four days.

It's a limited edition yeast that's no longer available since I pitched, so I decided to gamble... boiled a 6oz mason jar for ten minutes, let the water inside cool, and poured the water on the cake. Then I swirled it to liquify the cake and poured it back into the mason jar until it was overflowing, capped, and star-san'd the outside of the jar.

Am I good to slant this yeast when my glycerin arrives?

It should be fine. Won't be that different from growing it in a fermenter. Why not get some DME and pour some off into it so you have a second batch that's in active growth?

 

[Trail]

I've got about two pounds of DME sitting around, as well as a erlinmeyer flask. If it'll help things along maybe I'll do that Sunday night.

 

[k_mcarthur]

Sounds to me that you basically washed the yeast from the trub, right? When I want to add a new strain to my yeast bank from a previous batch I like to do it from an actively growing cell population like jordanmills suggested. In your situation to keep exposure to a minimum I would put the jar in the fridge and let it flocc out. Then when you want to use this strain again make a starter from it like you always do, when its at high krausen take your sample for storage. Good luck!

 

[Trail]

The contents of the jar in the fridge is all sludge, about the consistency of yogurt. I don't think it's likely to flocculate out in the near term. I don't know if I washed it <i>per se,</i> the main reason I added the water was to loosen up the cake enough to be pourable.

This is why I poured sludge until it overflowed before capping - I wanted to be as sure as possible that yeast was the only thing in the jar.

I'm not sure if I'll be using the yeast again soon enough to skip doing the starter -> freezing now. It's Wyeast 1026 Cask Ale, which is a specific enough yeast flavor profile that I don't see myself using it just for the hell of it.

 

[EarlyAmateurZymurgist]

For the benefit of other forum members, the OP is freezing yeast, not slanting yeast. Slants are screw-cap culture tubes in which a gelatinized growth medium has been allowed to cool at an angle; thereby, increasing the surface area of the medium (slants must be rendered absolutely sterile via autoclaving). Yeast is transferred aseptically to the surface of a slant using a laboratory tool known as an inoculation loop. Transfers are usually made plate to slant, slant to stant, or slant to a very small amount of autoclaved wort (usually 10mls or less). Slants can also be used in the field to capture new yeast strains for later plating. Unless one knows that one is dealing with a mixed culture, new yeast strains should always go through single-cell isolation on a plate before being aseptically transferred to a slant.

Here's a photo that I shot when I recently prepared "blank" slants and plates:

Here's a photo that I shot the other day of a yeast culture that is undergoing single-cell isolation:

The colonies in the rectangle are each the offspring of a single yeast cell; hence, they are single-cell isolates (Emil Hansen was the first person to produce a single-cell isolate). These colonies are good candidates for slanting because they are well separated and exhibit good morphology.

By the way, an autoclave is a just an advanced pressure cooker. One can use a standard kitchen-grade pressure cooker to autoclave media at home.

 

[WoodlandBrew]

The yeast will be better off if it is not active directly before from freezing. Fermentation depletes glycogen reserves, and the rest after fermentation allows yeas to rebuild these reserves.

 

[k_mcarthur]

I think there has been a little misunderstanding with terminology here. Slanting is not freezing granted, but slanting is also for long term storage as well as freezing. I will outline what I have done for both situations, keeping in mind there is more than one way to skin a cat as I have found yeast is a hearty organism. In the case of slanting I would wash the yeast of the trub twice. Then I would do a starter and wait for high krausen. Make an agar plate and using inaculating loop plate the yeast. Then slant chosen colonies. In the case of freezing, I would wash yeast from the trub twice. Then make a starter and let it ferment out. Pour liquid into sterile jar, and solids into tube. Add glycerin solution to tubes and add liquid to fill to brim and cap. Just my humble opinion.

 

[Trail]

I'm planning to slant the yeast, then freeze it. My question simply arises out of uncertainty whether the yeast stored as it is will be worth culturing, which I believe has been confirmed.

 

[k_mcarthur]

I don't think you can freeze a slant the way it is. In a slant the colonies are living on an agar gel and to freeze you want the yeast suspended in a glycerin solution so ice crystals don't damage the cell walls. Could you describe your process for clarity? I think I'm confused. FYI I have kept slants for almost a year just in the fridge, really no need to freeze.

 

[EarlyAmateurZymurgist]

In the case of slanting I would wash the yeast of the trub twice. Then I would do a starter and wait for high krausen.

Non-dormant cultures can be plated directly without restarting.

 

[k_mcarthur]

Non-dormant cultures can be plated directly without restarting.

I'm sure your right, I'm probably wasting time by starting it again. My thinking has been " I'm going to catch it in the height of growth phase". I'll try without it next time.