Recovering out of date yeast

[altone]

Ok, so lets start with an explanation:

We moved house about 18 months ago, I lost my mancave and room for my allgrain setup.
I've been doing basic kits and bits brewing since then.
All of my special yeasts and frozen samples were dumped into a plastic box and put in storage.

I'm finally getting back into all grain using BIAB and plan on getting a robobrew as it's all I have room for now.

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So I unpacked some of my old brew stuff and saw these yeasts - probably $200 worth.

I grew up in the North of England and we don't like throwing stuff away,

I have 3 flasks and a magnetic stirrer doing nothing, so I thought what the heck, let's see if I can revive any of them.

I checked mrmalty.com and the viability was "Are you insane?" [aka 1%] moving on - let's give it a go

I use the well documented methods for starters you can easily look up.

I thought even if I get no results, at least I'll have practiced the method and be ready when I want to split a new smack pack.

For the smack packs I chose a 1 litre flask - mainly because it's the biggest that will fit into my pressure cooker for sterilization.
An LDME solution at around 1.050 with a couple of hop pellets and a pinch of yeast nutrient.

First my beloved WY1469 with a mfg date of 2009 - yep 2009 I decided to do the oldest first.

After 4 days on the stirrer - mrmalty was right - no activity

Next i tried a WY1318 from 2011 - mrmalty was right

Then a WY1275 Thames from 2012 - after 3 days - krausen

Maybe the Thames or a wild yeast, so I made a small sample brew with DLME a bit of dark crystal and a mix of
Fuggles and EKG - tasted right - TAKE THAT mrmalty!!

I'm now trying a WY1762 Belgian dated 2013 that is also showing signs of life.


I guess my point is, don't chuck it out just because it's old.
Give it a whirl if you have time and gear to spare, you might just be pleasantly surprised.

I've got quite a few more smack packs to resurrect and also some yeast stored in glycerin but not frozen since the move that I'll try.

Whenever I'm not making a starter, I'll have one of these going on the stirplate.

As far as I'm concerned I'm already in front with 1 possibly 2 recovered yeasts.

Cheers

 

[sp0rk]

I think MHB resurrected a 5 or 6 year old Wyeast smack pack
As long as there are a few viable cells and you don't shock them too much, you can build them up

 

[jyo]

1030-35 is a safer gravity for stepping up.

 

[Yob]

For old yeast, first step should not exceed 1.020

And probably not much volume either... ~100ml > 500ml then 1.040 at 1000ml

 

[altone]

I think MHB resurrected a 5 or 6 year old Wyeast smack pack
As long as there are a few viable cells and you don't shock them too much, you can build them up

Yep, sure looks that way, and of course I'm doing my best to avoid infection and wild yeasts.

I pressure cook everything I can and use alcohol spray to avoid infections.
I also do all this in the laundry as it's low traffic and has never been used for brewing, so hopefully not full of yeast spores.

I'll try the glycerin stored yeast in a 250ml flask and bump it up if it looks viable.

Hopefully I can save a few strains - especially the ones that are seemingly unavailable right now.

Then once I'm happy I have the yeast I expected I'll start collecting and freezing them.

 

[altone]

For old yeast, first step should not exceed 1.020

And probably not much volume either... ~100ml > 500ml then 1.040 at 1000ml

Ooh - I'm going too hot on the sugars - ok will back it off for the next one.

As for the volume, I thought as the smack packs have about 125ml, 1litre wouldn't be too much, But yeah I'll go 500ml next time too.
Then do a step up to 1000ml at 1,040 if they fire up

Thanks for the info

 

[Vini2ton]

My great grandfather came from Haworth and I still hate throwing stuff out. Last week I ditched some washed 4 year old Ringwood which I'm still grumbling over. Should of had a crack at stepping it up. A couple months ago I used a sachet of US-05 for a 20 lt brew that was 18 months out of date. Turned out nice. Sort of the same as growing gardens, nature sure has some surprises. Some good, some bad.

 

[manticle]

I love throwing stuff out but only if its only use is for the never present Ron.

If it has a real, practical demonstrated use, keep it and look after it.

They've ressurrected yeast from bottles of beer over 1000 years old from memory. Probably higher tech than a bit of dme and magnetic stirbar but still - one (healthy non mutant) cell and you should be right as rain.
Worth having a crack.

 

[MHB]

With Old yeast I would be very inclines to get it started then let it ferment out before stepping up.
It will restock its Glycogen reserve and absorb a lot of odds and sods from the wort in preparation for doing dormant.
Letting it go through its full life cycle should give you healthier yeast and reduce the stress on the yeast, more better yeast less mutations and style drift.
Mark