Octoberfest yeast starter

[Terry Murphree]

I am concerned about this yeast starter. It is saved trub and yeast from a marzen brewed in January. The strain is WLP 820 a very good yeast for Marzen/Octoberfest. It has been kept in a refrigerator this entire time. I gave it a pint of 1.050 starter wort roused the yeast / trub got them to the same temperature and turned on the stir plate. I have my fingers crossed as I have a brew date scheduled on Tuesday to brew an Octoberfest.

 

[wepeeler]

You might need to step it up again, being that the yeast is 6+ months old. Take the airlock off and put a piece of tinfoil over the opening instead.

 

[IslandLizard]

Yeast starters need continuous access to oxygen to multiply. So, yes put a "tent" of aluminum foil over the flask opening instead. A 5x5" 6x6" piece of foil should work fine, then crimp it somewhat loosely around the neck. Not tightly squeezed, you should be able to rotate the aluminum "tent."

It looks like a 1 liter flask. Do you happen to have a bigger one, such as 2 liters? Would be more useful.

Use this calculator to estimate yeast viability, and size starter(s) needed to grow a suitable pitch. You may need to play a little with the various parameters/cells to get sensible numbers.*
http://www.brewunited.com/yeast_calculator.php

* 1. Set the top left cell to: Lager - 1.5 million cells per ml.
* 2. The more difficult part is estimating how many cells are in your saved out yeast slurry.

That's the number to enter in the first cell on the 2nd line:​

Your Yeast Details​

Initial Cell Count​

(billions) ​

If you need help with the estimation and calculations, give us some numbers.​

1. How much (volume) yeast slurry did you save from the previous batch, back in in January? Was that all of it or only a part?
2. How did you harvest it?
3. What's in your flask right now, all the yeast you had saved out in January?

 

[Terry Murphree]

Thanks for the replys. As of 12 hrs later I have no signs of activity. I have removed the air lock and placed tin foil on the top loosely. I don't know if it will help but I added another 6 oz of slurry. We will see what happens.