WLP 802 Yeast Bank / Propagation help

[RodeBrewingCo]

I am doing my first Yeast Bank / Propagation. First I am not even sure what is the proper term for doing a single type yeast and banking… that still banking?

The WLP802 Czech Budejovice Lager Yeast is what I used in a Bohemian Pils. Thread here. https://www.homebrewtalk.com/f39/lager-advice-514639/The batch came out so good I thought I would harvest and bank some

I made some LDME and added the yeast. Did that twice. Then cold crashed it. So the pic is a half gallon grower with my yeast.

I am going to make a glycerin/water solution then chill the solution. Add the yeast/solution to some tubes, freeze them.

Is there any consideration for sterilizing the glycerin? Making the water/glycerin batch then sterilizing?

Also what confuses me is…… most of the pictures I have seen of lager yeast ready for banking is that the yeast is below the trub. In my pic it is above the trub, like a ale yeast.

Does / can lager yeast sit above the trub after it’s been crashed?

 

[WoodlandBrew]

It's all good yeast. Most people will save the white creamy layer. How it stratifies is very strain depend. You probably don't need to sterilize the glycerin, but you may as well do it when you are autoclaving the vials. I use 10% glycerin and the rest slurry. It freezes and stays solid if it's in a cold spot in the freezer. Some studies have shown that higher concentrations of glycerin can lead to damage of the DNA.