Starter out of old washed yeast help

[huge1s]

I have a jar of washed WL300 yeast sitting in my fridge from the end of November 2011. Mr. Malty puts the viability at 10%. There is almost no "non-yeast" material in the jar and it is very thick (except for the water above it of course).

To get my target yeast count of 140 billion cells (I like to underpitch this hefe yeast), I used Mr. Malty to figure out that I need 5 vials of 10% viable yeast in a 1L starter (stir plate) to hit my target yeast count. I figured I could essentially use my washed yeast to make 5 vials (where the settled yeast is the same volume as a brand new vial). Am I thinking about this correctly? Is there a better method of figuring out how to make a starter from washed yeast?

 

[foltster]

Personally I would just make a 1L starter with washed yeast, make sure it smelled good, and roll with it. You might end up a little low on yeast count but it should be pretty healthy and ready to go after chewing through the starter. Good to see you have the stir-plate.

I would also look into getting a 2L or 3L flask for situations like this, 1L is almost never big enough for a "proper" starter, at least with my setup.

 

[pabloj13]

I have a jar of washed WL300 yeast sitting in my fridge from the end of November 2011. Mr. Malty puts the viability at 10%. There is almost no "non-yeast" material in the jar and it is very thick (except for the water above it of course).

To get my target yeast count of 140 billion cells (I like to underpitch this hefe yeast), I used Mr. Malty to figure out that I need 5 vials of 10% viable yeast in a 1L starter (stir plate) to hit my target yeast count. I figured I could essentially use my washed yeast to make 5 vials (where the settled yeast is the same volume as a brand new vial). Am I thinking about this correctly? Is there a better method of figuring out how to make a starter from washed yeast?

First, figure out how many live yeast you have on Mr Malty.

1. Go to Repitching from slurry tab. Set your yeast concentration to 4.5 and your non-yeast to 10%. Put in your viability. It will give you two numbers yeast cells needed and # mLs yeast needed and concentration. Divide first by the second to give you viable cells/mL

2. Multiply the actual volume of yeast you have (estimated by looking at settled yeast in your jar) times the viable cells/mL you just calculated. This gives you total viable cells.

3. Go to Yeastcalc.com and put in starter on stir plate, input how many billion cells you have and see how large of a starter you need.

4. ...

5. Profit.

 

[huge1s]

First, figure out how many live yeast you have on Mr Malty.

1. Go to Repitching from slurry tab. Set your yeast concentration to 4.5 and your non-yeast to 10%. Put in your viability. It will give you two numbers yeast cells needed and # mLs yeast needed and concentration. Divide first by the second to give you viable cells/mL

2. Multiply the actual volume of yeast you have (estimated by looking at settled yeast in your jar) times the viable cells/mL you just calculated. This gives you total viable cells.

3. Go to Yeastcalc.com and put in starter on stir plate, input how many billion cells you have and see how large of a starter you need.

4. ...

5. Profit.

Nice... I didn't spell it out, but I was thinking along the same lines. This helps a ton having someone else spell it out for me.

 

[huge1s]

First, figure out how many live yeast you have on Mr Malty.

1. Go to Repitching from slurry tab. Set your yeast concentration to 4.5 and your non-yeast to 10%. Put in your viability. It will give you two numbers yeast cells needed and # mLs yeast needed and concentration. Divide first by the second to give you viable cells/mL

2. Multiply the actual volume of yeast you have (estimated by looking at settled yeast in your jar) times the viable cells/mL you just calculated. This gives you total viable cells.

3. Go to Yeastcalc.com and put in starter on stir plate, input how many billion cells you have and see how large of a starter you need.

4. ...

5. Profit.

One question for you. Does the ml include the water sitting above the yeast? or does that assume I have decanted all/most of the water?

/edit
never mind... i should read more better!

 

[cram]

I just revived some CA ale yeast I had saved from last July on a stir plate. I made a 1L starter with 8 oz. of DME and a pinch of nutrient and let it ride. It took about 2 days on the plate before it started to get going (I thought it was a goner) but then it took off. I let it go for two days, put it in the fridge and decanted the liquid then added another 1L H20/1 cup DME solution and let it grow more. By this time it was a total kruasen volcano out the top. I plan to make beer from the starter this weekend (this morning, I drew off two vials to grow for next time) so I can't attest to any mutations or off flavors resulting from the long storage. But I can say the "beer" made on the stir plate smelled normal and the yeast was definitely viable, even though it took a lot longer to get going then a fresh one.

Long story short: give it time, step it up, and it should work out fine.

 

[pabloj13]

Nice... I didn't spell it out, but I was thinking along the same lines. This helps a ton having someone else spell it out for me.