[SecondRow_Sean]

Because sometimes my IQ drops 30 points without warning, I ordered yeast from NB last Sunday in the middle of the worst heat wave in recorded history. It arrived today and I'm wondering if the yeast is still viable. It's WLP830 and I was planning on making a 2-3L starter anyway. Should I do a two step starter just to make sure, or just do what I should have done all along and take my happy ass down to the LHBS and get more yeast?

[hopshead]

Make a two stage starter.  See if that yeast is good before you buy more.

[Jimmy K]

Not good news, but I'm sure the yeast is not completely dead. Two stage starter is a good idea.

[davidgzach]

I just received some 2007 Pilsen and made a 1G starter on Sunday.  On Monday there was very little activity so I checked the MFG date on the pack.  It was 4-10 or almost three months old for a viability of 33% per Mr. Malty.  This morning there are more bubbles coming up, but far from where it should be 2 days in on a stir plate. 

So not to hijack the thread, should I have made a 2 stage starter as well and why?

Dave

[nateo]

Yeast growth is affected by inoculation rate. I don't have the book Yeast in front of me right now, but there is a sweet spot of cells per ml that results in maximal growth. 1 gallon would be a pretty low inoculation rate for that viability. The sweet spot is about 1.5L to 4L for 100b cells, IIRC. If you're at 33% viability, multiply those volumes by 1/3 to get the optimal growth range (0.5L - 1.32L).

So to answer your question directly, ideally a stepped starter would be used to keep the inoculation rate in the sweet spot as much as is feasible. Let's say you have 33b cells, and they grow 100% in a 1L starter. Now you have 66b cells. The new "sweet spot' is 1L - 2.64L. Let's say they grow another 100% in a 2L starter. Now you have 132b cells. The new "sweet spot" is 2L - 5L, and so on.

If you're anything like me, once you crunch all the numbers to get a reasonable pitching rate, you'll quickly see the benefits of using dried yeast (20b cells per gram ~ 230b per pack, with reliably 90% viability).

[davidgzach]

Good info, thanks.  Need to buy that book!

[davidgzach]

But back to your post Nateo.  If I missed the sweet spot, and pitched 33% viable cells (or worse since it was a day in 100F heat from the LHBS), what now?  I guess I have to let this ride out since it's starting to show signs of life after 2 days.  But what will that mean to the end result of the starter?  Will it be ready for a lager in 3-4 days?  Or will I still be short on cells?

Hoping I'm staying within the OP's topic......

Dave

[beersk]

Yeast growth is affected by inoculation rate. I don't have the book Yeast in front of me right now, but there is a sweet spot of cells per ml that results in maximal growth. 1 gallon would be a pretty low inoculation rate for that viability. The sweet spot is about 1.5L to 4L for 100b cells, IIRC. If you're at 33% viability, multiply those volumes by 1/3 to get the optimal growth range (0.5L - 1.32L).

So to answer your question directly, ideally a stepped starter would be used to keep the inoculation rate in the sweet spot as much as is feasible. Let's say you have 33b cells, and they grow 100% in a 1L starter. Now you have 66b cells. The new "sweet spot' is 1L - 2.64L. Let's say they grow another 100% in a 2L starter. Now you have 132b cells. The new "sweet spot" is 2L - 5L, and so on.

If you're anything like me, once you crunch all the numbers to get a reasonable pitching rate, you'll quickly see the benefits of using dried yeast (20b cells per gram ~ 230b per pack, with reliably 90% viability).

Not much good lager yeast out there though is the problem with that assessment.
A friend of mine order yeast from Northern Brewer last week and I suggested getting the ice pack with it.  The yeast still arrived slightly warm, he said, but I showed him how to make a starter (1L starter), and that turned out fine. 

[nateo]

Beersk: S-189 (when you can find it) and W-34/70 are pretty good lager yeasts. Not that I'm accusing you of this, but I've seen other places that people who say "there aren't good dry strains" don't use dry strains often, or haven't used them in a number of years. Also, Fermentis is the only dry yeast I like to use. I've had too many long lags and poor performance from Danstar.

David: My gut estimate is you won't have nearly enough cells, but I could be wrong. I'd have to doublecheck the growth factors to be sure.

I live in the boonies now, and closest LHBS is an hour-and-a-half drive away. I always order ice packs with my yeast, but I've had to toss a few starters that refused to budge even after a week. There are a few Belgian strains I'll mess with, but otherwise there are dry strains for 95% of what I brew.

[kylekohlmorgen]

Good info, thanks.  Need to buy that book!

I had to read this part of the book a few times to really get it (and I'm a chemical engineer!). They explain it VERY well - you just can't let your thoughts wander off to how you're going to apply it.

What an AMAZING book, though. Its a must read if you really want to manage fermentation properly.

[davidgzach]

Nateo,

I feel your pain.  The closest LHBS to me is 45 minutes and a couple of tolls on the Turnpike.  It's cheaper to have it shipped and it arrives next day.  I always get the ice pack, but did not expect the yeast to be almost 3 months old to start with.  I probably ended up with ~10% viability but that is just a guess.

I'm using more US-05 and WB-06, but I really like experimenting with 10G batches split with different yeast.  So this one is an American Lager with 2035 and 2007.  I'll have to see how the next couple of days go as it seems to be picking up steam. 

Dave

[davidgzach]

Because sometimes my IQ drops 30 points without warning, I ordered yeast from NB last Sunday in the middle of the worst heat wave in recorded history. It arrived today and I'm wondering if the yeast is still viable. It's WLP830 and I was planning on making a 2-3L starter anyway. Should I do a two step starter just to make sure, or just do what I should have done all along and take my happy ass down to the LHBS and get more yeast?

Sean,

How is your starter coming along?  Did you go 2 stage?  My 1G starter now has a good Krausen line and looks to be very healthy.  Wouldn't have thought it possible on day one. 

Dave

[SecondRow_Sean]

Might not be able to brew this weekend, so I haven't started it yet. The tube is sitting in my fridge now. Glad to hear yours is up and running, hopefully mine will do the same.

[davidgzach]

Might not be able to brew this weekend, so I haven't started it yet. The tube is sitting in my fridge now. Glad to hear yours is up and running, hopefully mine will do the same.

I'm sure it will.  Good luck!

Dave

[narvin]

Check out mrmalty.com.  They have a yeast starter size calculator.  Even with healthy pack of yeast, you might not have enough for a lager.