Collecting and storing yeast from starters.

[maida7]

I'd like to build a yeast bank from making starters from white labs liquid yeast vials. I have a few questions

Can I store the resulting yeast in the fridge? How long will it stay good? I'm thinking small 4 oz jelly jars would be a good size? Can I sanitize the jars with star san or do I need to boil them or do I need a pressure cooker?

TIA

 

[chode720]

Check out the Mr Malty pitching rate calculator:

http://www.mrmalty.com/calc/calc.html

Your stored yeast will lose viability over time, but all that means is that you will have to add more yeast and/or make a bigger starter.

I basically store my yeast the same way u are thinking. After I ferment a batch, I was the yeast and store it in small vials, or in pint mason jars. I just sanitize them with Star San and then pour the yeast into them. Then I pop them in the fridge and havent had any issues yet

 

[TipsyDragon]

yes you can keep the yeast in the fridge. they could be good for millions of years. the jar size is up to you. use what ever works. assuming the jars are clean to begin with StarSan will be just fine for sanitation.

now with that said you will probably need to make a starter with your stored yeast to get them to wake up and grow again.

 

[EvilGnome6]

I have recently started storing yeast from starters and it has been working well for me. Here's my process:

1) Make a 600mL starter from a jar of saved yeast or from a new vial/smack pack.
2) Place on stir plate for two days or until it ferments out (the older the yeast, the longer it takes to start).
3) Stop the stir plate and let the yeast settle for 24 hours.
4) Decant 300mL of beer from the top of the flask.
5) Poor 100mL each into two 4 oz. Jelly Jars (carefully sanitized of course).
6) Use the remaining 100mL to step up to a 1L starter to pitch into the next batch.
7) Label the Jelly Jars and pop them in the fridge for future use.

I start this on Monday nights in preparation for a Sunday brewday. This gives me plenty of time to make sure the yeast is viable and even if the first starter is sluggish to get going, the second starter will be really healthy. I far prefer this to using washed yeast from the primary.

 

[maida7]

Check out the Mr Malty pitching rate calculator:

http://www.mrmalty.com/calc/calc.html

Your stored yeast will lose viability over time, but all that means is that you will have to add more yeast and/or make a bigger starter.

I basically store my yeast the same way u are thinking. After I ferment a batch, I was the yeast and store it in small vials, or in pint mason jars. I just sanitize them with Star San and then pour the yeast into them. Then I pop them in the fridge and havent had any issues yet

I'm familiar with the Mr Malty calculator. It's great! I use it all the time for sizing my starters. I guess for this method I would use the pitching for a slurry tab. In that tab, anything past 50 days old is fixed at 10% viability. Is 50 days a reasonable shelf life. Assuming the sample is refrigerated.

After 25 days it's roughly 50% viability. Would you do a 2 step starter with anything past 25-50 days? And maybe a one step starter with anything 25 days or fresher?

 

[maida7]

I have recently started storing yeast from starters and it has been working well for me. Here's my process:

1) Make a 600mL starter from a jar of saved yeast or from a new vial/smack pack.
2) Place on stir plate for two days or until it ferments out (the older the yeast, the longer it takes to start).
3) Stop the stir plate and let the yeast settle for 24 hours.
4) Decant 300mL of beer from the top of the flask.
5) Poor 100mL each into two 4 oz. Jelly Jars (carefully sanitized of course).
6) Use the remaining 100mL to step up to a 1L starter to pitch into the next batch.
7) Label the Jelly Jars and pop them in the fridge for future use.

I start this on Monday nights in preparation for a Sunday brewday. This gives me plenty of time to make sure the yeast is viable and even if the first starter is sluggish to get going, the second starter will be really healthy. I far prefer this to using washed yeast from the primary.

Excellent! This is exactly what I'm thinking. I'd rather not collect yeast from my Better Bottle carboy. I can't see how you could properly sanitize the opening since it can't be flamed and it's usually coated in gunk.

How long do you typically store the jars between uses? Is there a time period where you start to have poor results? Ever run into a problem with an infection using this method? At some point do you just ditch everything and start over fresh?

 

[EvilGnome6]

How long do you typically store the jars between uses? Is there a time period where you start to have poor results? Ever run into a problem with an infection using this method? At some point do you just ditch everything and start over fresh?

I store the jars in the crisper drawer of my beer fridge until I need them. I've used jars of yeast that were 6 months old with no issues. Sometimes the old jars take a day to get going and other times they take off within hours.

I haven't had an infection so far. I don't even bother flaming the lip of the flask. I just hit it with a spray bottle of sanitizer solution around the edge before I remove the foam stopper. Everything else gets soaked in sanitizer solution until right before I need it and I try to work quickly.

I haven't gone beyond 4 generations this way but that's only because I haven't reused a specific strain that many times, yet. I'll keep trying this until it fails but so far 6 months with 4 generations doesn't seem to be a problem at all.

 

[maida7]

Awesome! Thanks for the info!

 

[chode720]

I'm familiar with the Mr Malty calculator. It's great! I use it all the time for sizing my starters. I guess for this method I would use the pitching for a slurry tab. In that tab, anything past 50 days old is fixed at 10% viability. Is 50 days a reasonable shelf life. Assuming the sample is refrigerated.

After 25 days it's roughly 50% viability. Would you do a 2 step starter with anything past 25-50 days? And maybe a one step starter with anything 25 days or fresher?

In John Palmer's book, How To Brew, there is a chart that shows what your final cell count will be, based on your initial cell count and the size of your starter (at 1.04). I looked on the website and couldn't find it, but I know the chart is in the most recent copy of his book.

So what I do is use the Mr Malty calculator for pitching slurry to find the vialility for my yeast. The calculator will also show you how many mililiters of yeast is need at that viability to achieve the cell count you need. From there, I calculate the number of cells that are roughly in my yeast and then using the chart in Palmers book, figure out how big of a starter to make.

For instance, Mr Malty told me on my last beer that I need to pitch about 160ml of yeast and that would give me a cell count of about 192 billion cells. However, I only had 100ml of yeast (mason jars with measurments are great for being able to tell this). So what I did was divide the 192 by 160 and found that at that viability, I had 1.2billion cells per ml. So then knowing I had 100ml of slurry, I figured i had roughly 120billion cells of viable yeast in there. Then I went to Palmers book found the row for 120 billion cells, and how big of a starter I would need to get teh 192 billion cells that the Mr Malty calculator said I needed.

Does that make sense?