Old yeast

[scottballz]

I have a vial of wlp565 saison yeast laying around I would like to use. The best before date was aug 2nd so I'm guessing most of the yeast cells are not viable. I was thinking of doing a starter and then stepping it up to bump up the yeast count. Or is that just a waste of time and dme? Thoughts?

 

[m1k3]

do a starter, if it smells good and starts normally... use it.

if not, don't waste wort to use old yeast.

 

[scottballz]

Sounds good

 

[flars]

All of the yeast cells didn't die in the last five days. Use this calculator to help build your starter.
http://www.brewunited.com/yeast_calculator.php
White Labs has said there will still be some viable cells after one year.

 

[fun4stuff]

I have a vial of wlp565 saison yeast laying around I would like to use. The best before date was aug 2nd so I'm guessing most of the yeast cells are not viable. I was thinking of doing a starter and then stepping it up to bump up the yeast count. Or is that just a waste of time and dme? Thoughts?

yeah, youll be fine. ive used vials that were many months passed due. Just be sure to make a starter.

If you like you can calculate how many yeast cells remain from the date of production and then calculate how big/many starters you need according to the beer that youre making using online calculators.

 

[OzzyBrew]

I have a local brew store that gives me free wyeast 'past date' yeast. I usually start it out in a 1l starter, build it up a couple of time and then use it. I had one that was 8 months passed the best by date.....ramped it up 3 times and made the best Cali Common I have ever made! Good luck!

 

[Calder]

I would have no issues if it were dated 8/2/14. Just make a starter and all will be well.

 

[illmatija]

So I am in the similar situation because I have 5-6 packs of yeast that are around 6 months old. According to mrmalty, viability is 10-20%. A single starter would probably result in underpitching according to calculators, which is why I do two step starter. What I do is calculate as if I start with around 10-20% yeast, and do a two step starter. For example, I needed around 200B cells, and according to mrmalty had 15% (15B) viability. So I put that number in brewersfriend to calculate a two step starter.

I make the first one with around 1.5l, and once it's done, cold crash it, decant the starter beer, and wash the yeast of all the dead cells - put a few cups of preboiled cold water, mix it, let the dead cells and trub settle for 15 mins (depends on how flocculent the yeast is), and then decant the liquid that should contain healthy yeast to a sanitized container.

Then I do another, probably bigger starter (3L) with the decanted liquid, depending on the fermentation parameters for the main batch.

Somewhat complicated, but I believe this is the right thing to do to get the appropriate cell count.

 

[flars]

So I am in the similar situation because I have 5-6 packs of yeast that are around 6 months old. According to mrmalty, viability is 10-20%. A single starter would probably result in underpitching according to calculators, which is why I do two step starter. What I do is calculate as if I start with around 10-20% yeast, and do a two step starter. For example, I needed around 200B cells, and according to mrmalty had 15% (15B) viability. So I put that number in brewersfriend to calculate a two step starter.

I make the first one with around 1.5l, and once it's done, cold crash it, decant the starter beer, and wash the yeast of all the dead cells - put a few cups of preboiled cold water, mix it, let the dead cells and trub settle for 15 mins (depends on how flocculent the yeast is), and then decant the liquid that should contain healthy yeast to a sanitized container.

Then I do another, probably bigger starter (3L) with the decanted liquid, depending on the fermentation parameters for the main batch.

Somewhat complicated, but I believe this is the right thing to do to get the appropriate cell count.

Mrmalty is not very accurate on viability. Use
http://www.brewunited.com/yeast_calculator.php
which is more real world.

It is very difficult to tell the difference between a live yeast cell and a dead yeast cell unless you are using a microscope and dyes. Dead yeast cells will not drop out faster than live yeast cells.

You are really over thinking it, but you may end up with a sufficient pitch rate anyways.

 

[TheMadKing]

Do a starter and cold crash it. The yeast will settle into darker and lighter layers. The lighter layers are your new viable cells. Decant off the liquid, pour the viable cells into a sanitized mason jar and dump the rest. Redo the starter and assume ~2 billion cells/mL in the slurry. You'll have fresh viable yeast and no autolyzed cells to worry about.

 

[illmatija]

Mrmalty is not very accurate on viability. Use
http://www.brewunited.com/yeast_calculator.php
which is more real world.

It is very difficult to tell the difference between a live yeast cell and a dead yeast cell unless you are using a microscope and dyes. Dead yeast cells will not drop out faster than live yeast cells.

You are really over thinking it, but you may end up with a sufficient pitch rate anyways.

Whether it's 15% (mrmalty) or 35% (brewunited), I get sufficient yeast in either case and won't underpitch or overpitch too much (cca 200B cells vs 250B cells).

If I had a stir plate, I wouldn't need the whole two-step starter, but currently I don't so I have to do a two step starter. The whole yeast washing might be irrelevant though.

This calculator is cool, but it is slightly annoying in that you can't set up the starter steps fixed and change the input parameters without starter sizes resetting.