Let's Freeze Some Yeast

[malt junkie]

I use a beaker then a huge syringe, well 2 syringes one for yeast one for glycerin mix.

 

[kaiserben]

Ah cool, just re-read this thread and saw the syringes in the first post.

What syringes are you guys using? (are they autoclavable? If not, what are you doing to sanitise them?)

 

[malt junkie]

Chemist... well not one in a small town but most big chemists should carry some decent size ones, I just throw them is the pressure cooker when I do a couple batches of vials. I have two 50ml need to track down some spares though.

 

[Yob]

Started with that, don't use them bow as it's just more risk

 

[kaiserben]

I might try pouring from my Erlenmeyer into a pressure cooked pyrex jug (which has a spouty-type thing to make pouring somewhat easier) and then from there into the vials.

Right-e-o, I've just bought a bunch of stuff:

I bought 3 x 21 hole rack vial holders: link for AU$11.26 delivered.
2 x 1kg Vegetable Glycerine: link for AU$30.85 inc delivery.
4 x 10 centrifuge vials: link for AU$22 delivered (was gonna get this from Proscitech, was a bit unsure if I wanted to pay $15 on shipping for $25 worth of stuff (ie $40 total for 50 vials/LCA03), eventually decided I'd buy anyway, but then discovered they still had to add GST on top AND were charging GST on the shipping. Only added $4 more, but still ...)

 

[Tony121]

Random question, does the glycerine break down or go off if you keep it for an extended period of time?

Reason I ask is that I bought a 5kg bottle for about $25 and can't see me using it all for some time.

 

[kaiserben]

By the time a yeast pack gets to me it's usually a few months old (sometimes older, rarely younger).

According to YeastCalc 3 months after the manufacturing date means the original 100bn viable cells are more like 46bn.

So as an example, assuming I have a "fresh" pack of yeast with 46bn viable cells, what is everyone's opinion on whether it's better to:

1. Split the fresh pack of yeast into vials as is.
or
2. Do a starter to build the cells up a bit and revitalise the cells.

I realise there is a bit of a trade-off, where it would no longer be a pure/1st-gen culture once you've performed a starter, but at least the yeast you're freezing will be healthy and in good numbers.

What are people's thoughts on this?

 

[peteru]

You could do both. Archive 1/2 the pack and make a starter from the other half. You can compare the results down the track and decide which method you prefer.

 

[Mardoo]

I'll grow the pack up in that situation, just to ensure the yeast is well-fed and healthy and ready for the big sleep.

Another solution is to get onto Brewman's Wyeast pre-ordering buys. The yeast comes fresh as! You may still be able to squeak in on the current one, but hurry.

Also, you can contact the other forum supporters and find out when their next order is and see whether you can pre-order.

 

[kaiserben]

Yeah - I've recently jumped in on an AHB Yeast Bay bulk buy, and also just pre-ordered a couple of strains from the White Labs Vault.

 

[Mardoo]

How'd you do the Yeast vault pre-order?

 

[kaiserben]

Via my LHBS. (Dunno if they're a forum sponsor though)

Check this forum thread: http://aussiehomebrewer.com/topic/94457-white-labs-wlp059-melbourne-ale-yeast-to-be-released/

 

[kaiserben]

And this info from White Labs: http://www.whitelabs.com/news/the-vault-hits-production-2017

 

[Meddo]

Looking to start some yeast freezing shortly, I'm gradually working my way through this thread but haven't yet found much mention of splitting White Labs Purepitch packs as opposed to Wyeast smack packs. The White Labs packs only have ~40 mL of yeast/slurry compared to the 125 mL in a Wyeast smack pack.

Given that it seems the consensus is to go 25% water / 25% glycerin / 50% yeast slurry, I've got 50 ml vials, and would like to get 5 vials worth from a Purepitch pack, would the best practice option be:

1 - 4 mL water / 4 mL glycerin / 8 mL yeast ( 16 mL total in 50 mL vial, 25/25/50 )
2 - 21 mL water / 21 mL glycerin / 8 mL yeast ( 50 mL total in 50 mL vial, 42/42/16 )

or just grow up a starter and go:

3 - 12.5 mL water / 12.5 mL glycerin / 25 mL yeast slurry from starter ( 50 mL total in 50 mL vial, 25/25/50 )

It seems from what I have read that the 50/50 water to glycerin mix is optimal, and the mix volume should match or exceed that of the yeast? If that's the case then the first two options really only differ in the amount of headspace in the vial and how quickly I burn through my glycerin stash, so is there any downside to having 30+ mL of headspace in a vial as per option 1? (apart from inefficient use of freezer space)

If 8 mL of yeast won't be enough to easily culture up upon thawing (for a yeast-wrangling beginner) then option 3 gives me a full 25 mL yeast in each vial but presumably with an increased likelihood of infection.

Thoughts?

Thanks (and apologies if this has already been answered)

 

[Lord Raja Goomba I]

Looking to start some yeast freezing shortly, I'm gradually working my way through this thread but haven't yet found much mention of splitting White Labs Purepitch packs as opposed to Wyeast smack packs. The White Labs packs only have ~40 mL of yeast/slurry compared to the 125 mL in a Wyeast smack pack.

Given that it seems the consensus is to go 25% water / 25% glycerin / 50% yeast slurry, I've got 50 ml vials, and would like to get 5 vials worth from a Purepitch pack, would the best practice option be:

1 - 4 mL water / 4 mL glycerin / 8 mL yeast ( 16 mL total in 50 mL vial, 25/25/50 )
2 - 21 mL water / 21 mL glycerin / 8 mL yeast ( 50 mL total in 50 mL vial, 42/42/16 )

or just grow up a starter and go:

3 - 12.5 mL water / 12.5 mL glycerin / 25 mL yeast slurry from starter ( 50 mL total in 50 mL vial, 25/25/50 )

It seems from what I have read that the 50/50 water to glycerin mix is optimal, and the mix volume should match or exceed that of the yeast? If that's the case then the first two options really only differ in the amount of headspace in the vial and how quickly I burn through my glycerin stash, so is there any downside to having 30+ mL of headspace in a vial as per option 1? (apart from inefficient use of freezer space)

If 8 mL of yeast won't be enough to easily culture up upon thawing (for a yeast-wrangling beginner) then option 3 gives me a full 25 mL yeast in each vial but presumably with an increased likelihood of infection.

Thoughts?

Thanks (and apologies if this has already been answered)

Hey Meddo, I've just done this twice, let me have a chance to formulate "what I did" and I"ll post back.

 

[Lord Raja Goomba I]

[SIZE=10pt]I had two WLP 'pitchable yeast' packs.[/SIZE]

[SIZE=10pt]One was out of date (a freebie from a nice retailer) and one was in date.[/SIZE]

[SIZE=10pt]For the In date one, I built a starter, starting with 500ml at 1.035-ish, on the stir plate for 24 hours and then pitched another 1L at the same SG straight in. This took about 24 hours more, and after cooling, I was ready to freeze in about 3 days (though I took an extra day to stuff around and get to it).[/SIZE]

[SIZE=10pt]I ended up with 6 vials (50ml vials, so 25ml of yeast per vial) and froze 5 using the 25/25/50 ratio of water/glycerine/yeast.[/SIZE]

[SIZE=10pt]I pitched the 6th just this morning, so I'll let you know how that goes.[/SIZE]

[SIZE=10pt]With the out of date one, this took (understandably) longer.[/SIZE]

[SIZE=10pt]I built a 1L starter at 1.020. Waited for it to ferment out in 2 days, cooled, decanted the wort, 2L at 1.020, repeat the ferment and cool and decant. Then 1.0L at 1.040 of wort for another 2 days, decanted, and another 2L at 1.040.[/SIZE]

[SIZE=10pt]From this, I managed 5 vials and froze these using the above 25/25/50 ratio.[/SIZE]

 

[Lord Raja Goomba I]

And it's off. 2 inches of Krausen on a low grav beer (and I kinda abused the non-frozen yeast, by leaving it in the fridge sans-glycerine and no starter for a couple of weeks).

I'm impressed.

 

[kaiserben]

re-activating: Are you guys cold crashing between steps or just adding the 200ml to the 500ml of fresh wort etc? (I'll make up the next step to include the volume.. so, if I have a 500ml starter, Ill make up a 200g/1.5lt starter and add the 500ml to make the full 2000ml if that makes sense?)

This little bit of info from Yob has really streamlined my starter-steps process.

It might already have been obvious to a lot of people, but it wan't to me. Previously I'd been crash chilling between every step when doing multi-step starters, ditching spent wort and the whole process was time-consuming and fiddly. But this method is way easier, saves heaps of time and gives me more options.

 

[mofox1]

This little bit of info from Yob has really streamlined my starter-steps process.

Yup. He's a keeper, that's for sure (sorry, "fo' sho").

 

[Yob]

Fo shoz?