Let's Freeze Some Yeast

[Danscraftbeer]

Its that close then. Bummer. So set the pressure cooker at release option to sanitize the plastic vials at ~100c.

 

[mofox1]

The whitelabs PET blanks do amusing things even in a vegie steamer... think prawn crackers and you aren't too far wrong.

Hate to think what would happen in a pressure cooker.

 

[kaiserben]

For the record: after nearly 5 months frozen I've had no problem getting a single vial of WLP029 to take off and can see, from what settled to the bottom after removing from the stir plate, that it most definitely multiplied in my initial 0.3L of 1.020 wort. I'm guessing I now have about 30 ml of solids (would've been only ~12.5 ml or so to start with).

Following on from the above the rest of the process was simple, as per usual yeast building.

I'm usually pretty strict about (calculated) pitching rates, but for this lot I just built till the amount of solids looked about what I'd usually have for this type of beer.

I'm tasting this batch now and it's great.

 

[Mardoo]

Its that close then. Bummer. So set the pressure cooker at release option to sanitize the plastic vials at ~100c.

The polypropylene ones don't deform unless you squeeze them in too tight or rubber band them. Otherwise, since they're just on the edge, they keep their shape.

 

[DJ_L3ThAL]

The ones you recently got in the BB Mardoo have been through a legit dental autoclave (131degC) and came out absolutely perfect no change at all!

 

[Mardoo]

Good to hear! I'll remember that for the future.

 

[Danscraftbeer]

Probably a repeat question but.
Is it best to freeze a liquid yeast from the original vial? I'm thinking yes its the best as to keep the original strain.
Rather than building it up in a starter and taking from the yeast cake post ferment. I'm thinking just a tad from the fresh vial enough for one vial to freeze then step up the remainder of the vial for the brew day etc.

 

[Lyrebird_Cycles]

The ones you recently got in the BB Mardoo have been through a legit dental autoclave (131degC) and came out absolutely perfect no change at all!

The autoclave will run at 121 oC not 131. It is actually 250 oF "metricated". Bloody Septics.

 

[Lyrebird_Cycles]

Can you pressure cook all plastic vials as like the Whitelabs PET and the Vic Swap give aways etc? For sanitization etc.
I'm just about to test the idea but will they melt or warp at 125c?

Polymers will shift from a glassy state to a rubbery state at a temperature known as the glass transition temperature, Tg. Generally speaking, heating a polymer above its Tg will result in distortion which will "set" once the temperature is lowered so it is sometimes called the Heat Distortion Temperature or HDT.

Low Tg polymers include polyester (PET, recycle code 1, Tg 70 - 80 oC), low- and high- density polythene (LDPE and HDPE, recycle codes 2 and 4, Tgs ~ 90 and ~ 110 oC) and polystyrene (PS, recycle code 6, Tg ~ 100 oC)

None of these can be autoclaved safely.

Higher Tg polymers include polypropylene (PP, recycle code 5, Tg dependant on crystal structure but usually > 120 oC) and polycarbonate , (PC, one of many polymers includes in code 7 "other", Tg around 150 oC).

These can be autoclaved.

Transparent lab gear is often made from acrylic (PMMA) or polymethylpentene (PMP), both are also under code 7 "other". If it's transparent and brittle it's probably one of these, you can tell them apart by colour, PMP usually has a slight yellow cast.

Both polymers have wildly variable Tgs from well below 100 oC to around 150 oC, dependent on structure, so some items are safe and some are not.

BTW code 3 is vinyl or PVC, the heat stability of which depends on the extent of plasticiser used so no generalisation is useful: not much point comparing a down pipe made from UPVC (=Unplasticised PVC) to a piece of flexible vinyl tubing (heavily plasticised, which is why it is flexible).

 

[hoppy2B]

Has anyone mentioned using methylated spirits to sterilise their little tubes and things? I normally just reach for the metho when opening up packets of dry yeast etc.

I haven't been following this thread throughout its entire length, so apologies if it has already been discussed.

 

[Yob]

What brought you back hoppy? A desire to strut your stuff again?

Selling zomes?

There are much better thing to use than methylated spirits...

 

[Yob]

Has anyone mentioned using methylated spirits to sterilise their little tubes and things? I normally just reach for the metho when opening up packets of dry yeast etc..

https://en.wikipedia.org/wiki/Denatured_alcohol

For wiping a dry yeast, probably not an issue, ****** if I'd put it anywhere near anything coming in contact with my yeast though... but dry yeast isnt this discussion now is it?...

 

[hoppy2B]

https://en.wikipedia.org/wiki/Denatured_alcohol

For wiping a dry yeast, probably not an issue, ****** if I'd put it anywhere near anything coming in contact with my yeast though... but dry yeast isnt this discussion now is it?...

Metho evaporates so I wouldn't expect it to cause any problems with yeast as long as you let it evaporate first Yob.

Nice to see you again too Yob.

 

[kaiserben]

How important do you reckon O2 is for the first step when reviving frozen yeast in ~1.020 wort?

I ask because my stir plate will probably be being used for something else when I get home tonight, but I really need to un-freeze some lager yeast and get it ready for building up the cell count asap.

 

[eldertaco]

How important do you reckon O2 is for the first step when reviving frozen yeast in ~1.020 wort?

I ask because my stir plate will probably be being used for something else when I get home tonight, but I really need to un-freeze some lager yeast and get it ready for building up the cell count asap.

I wouldn't worry about it, I've revived from frozen into a jar with 150ml or so of 1.020 and no stir plate quite a few times now.

I just give it a shake every now and then instead, but once or twice would probably be enough I reckon.

 

[kaiserben]

So following on from the above 2 posts I had no problems with minimal O2 in my initial reanimation starter (although there definitely wasn't as much new yeast created as I'd seen with previous yeasts when I did use a stir plate).

This starter is now on to it's 3rd step at just over 3L and I had krausen sneak out over the lip of my flask and it's now all sticky under the foil (this is a lager yeast). Now I'm going to need to clean the outside and the rim of the flask somehow ...

 

[Nullnvoid]

Need some advice.

Trying to start some greenbelt which has been in the freezer.

Started at 200ml at 1.020. Was on the stir plate for 24 hours (probably too long).

Then 500ml at 1.040. Its currently been 24 hours. No visible action has occurred. Could it be dead? The temperature has been 20-22degrees.

Should I leave it at that for longer or try to go into 2000ml or something else entirely?

Cheers

 

[Midnight Brew]

Need some advice.

Trying to start some greenbelt which has been in the freezer.

Started at 200ml at 1.020. Was on the stir plate for 24 hours (probably too long).

Then 500ml at 1.040. Its currently been 24 hours. No visible action has occurred. Could it be dead? The temperature has been 20-22degrees.

Should I leave it at that for longer or try to go into 2000ml or something else entirely?

Cheers

I’d leave it an extra day and assess if the colour of the wort has changed. Currently have the same yeast on 200ml and today into a 1L starter. I’ll keep you updated

 

[Nullnvoid]

Cool. That's what I would have to do. I wouldn't be able to do anything else for 24 hours anyway.

It's obviously what I got off you. It's been frozen since I got it from you.

 

[Nullnvoid]

So to follow up, leaving it another 24 hours did the trick and it took off. Then stepped up to 2 litres no problems!

Now I have some vials about to have a sleep and some more back on the stirplate to go into an IPA!