How To...Grow on Liquid Yeasts

[Aleman]

Just to add my thoughts.

Thats a really good how to, as you say the important bit is to keep things as sterile as possible, which is why I use Pasta Sauce Jars to store yeast starter wort (They get pressure cooked totally sterile) . . . I would use glass wherever possible its just more robust than PET. . . . Long term storage is better accomplished under sterile water (Yes really sterile, bottle of water in the pressure cooker for 15 minutes), and yes the fuller the better as it dilutes the remaining yeast 'food' from the slurry . . . the more water the less food the better the yeast enter 'suspended animation'

Well done MTF

 

[MEB]

Thanks Aleman. And thanks for the extra tips. The jars are an excellent idea and one i will switch to once i've got some of them.

Sorry for the absence chaps. Unfortunately i got called away on business for a week. My starter has been left way longer than i should have left it. :pray: :pray: :pray:
I'm sterilising bottles today and am going to split it down to 6. Thats if it doesn't smell like rancid vinegar...

Pic's will follow if all is still good. :pray: :pray: :pray:

 

[Wez]

Great to have you back M

 

[russt1969]

Great post this one. Looking forward to the next instalment.
Splitting. :)

 

[MEB]

It's nice to be back.
I've got a busy week ahead doing some more photography for Dept of Conservation. I'm not complaining but it means i'm flat out sorting out the pic's and all that. Much rather be brewing.
Luckily enough the yeast had exhausted the sugar supply, done it's thang and all seemed good. So sunday morning i finished off splitting the yeasts into the 6 PET's. Took some pic's and will be uploading them shortly...

 

[MEB]

Now the yeast has exhausted it's food supply and grown considerably i have enough to split into PET bottles. I use PET's cos i have hundreds of the things. They are convenient but as Aleman points out not as good as glass. As i brew quite frequently( :whistle: ) i will get through these reasonably quickly so i'm not too bothered about long term storage-if i was i would make up some agar slants. Which i have done with 3 yeasts so far.
I generally figure that the yeast has utilised all the sugars it can when i give it a good swirl and the yeast breaks into lumps rather than mixing straight in. Also if i swirl and no frothy head appears instantly. It's not very scientific but neither am i. This has come about by trial and error and what works for me. Once i have some more time i'll study and learn the scientific details a bit more. For now it serves me fine.

 

[MEB]

I pour off the spent wort. Leaving behind just the usuable yeast. As you can see this is a considerable amount of yeast compared to the tiny amount that was initially added to the wort.

From this point on i am very carefull to not be slow or forgetfull with my procedure. The yeast must be at it's most vulnerable at this point :pray:

 

[MEB]

I then pour in approx 2L of water that has been boiled and cooled down. This then gets a good shake to mix the yeast with the sterile(ish) water. At this stage i flame the neck of the DJ every time i open it. I have tried to find out what 'flaming the neck' really is but can't so i hit it with a blast from my MAPP gas torch. I'm pretty dam sure no beasties would survive this. The opening of the DJ is the first to come into contact with anything so flaming hopefully helps to kill any nasties that are trying to attack my precious yeast.

At this stage i work as quickly and efficiently as i can. This is when your most likely to get an infection i reckon.

 

[MEB]

During this time my PET's have been sitting with sterilising solution in them. I pour this away and give them a good rinse. One at a time to ensure i can be as sterile as my conditions allow.

I also have a jug filled with sterilising solution and my funnel gets a good soak too.

 

[MEB]

I then give the DJ with the yeast in a good shake to thoroughly mix the yeast with the water. I quickly pour an amount of this into the PET bottle. Approx a third of the PET's capacity. I then quickly screw the cap on. I then flame the neck of the DJ and continue with the next PET untill all the yeast mix is dispensed from the DJ into the PET's. I then fill the PET's up to the brim with the remaining sterile water. I boil approx 6 litres water to allow sufficient sterile(ish) water to easily fill all the PET's.

As you can see there is a nice layer of yeast in the bottom of the PET's.

 

[MEB]

I label the PET's now and they go in my fridge. These should be good for up to a couple of month's. Plenty of time to use them for brewing. If your not doing 6 brews every couple of month's your a slacker and need to pull your socks up. :lol:

So there you have it. That's exactly how i deal with my yeasts. It's easy and should be able to be performed by any brewer without too much fuss. As a note i've also done this with S04. Not cos i'm tight just because i wanted to see if it could be done with dried yeasts. It can. I've also used the same method with yeast slurry collected from the FV after i've racked off a batch of ale. I used about 4 tablespoons of the slurry.

Next time i do a batch of Agar slants i'll document that too. But that'll be a while as i now have 18 bottles of yeasts to get through.

As i've stated. This probably isn't the definitive way to do it. It just show's you what can be done if you sterilise as best as you can and have limited access to proper lab equipment. The best thing about this is the wonderfull flavours and depth these yeasts can give your brews.

 

[russt1969]

Really good post there MEB. :clap:
I'm getting right into this yeast stuff. Did my 1st wash last week and added it to a brew on Sunday and its bubbling away like a good un.
Looks like its time to get some glass jars and get that fridge stocked up :)

 

[MEB]

Good on ya dood. I'm fascinated by yeasts and the different flavour complexities they add to my brews.

 

[Wez]

Great How To MEB, this is one i'll come back to again and again :clap:

 

[Wez]

A couple of Q's as I'm doing this tomorrow

Flaming the neck of the demi - is it essential and can I do it with a lighter ?

I was planning on using clear PET bottles - is this a good or a bad idea?

 

[Aleman]

Flaming the neck of the demi - is it essential and can I do it with a lighter ?

Yes it is, and no not really. I bought a plumbers propane torch from BnQ (Actually for plumbing but thats another story :) ) which doubles as a great bunsen burner :) Ideally when doing wort/yeast transfers you should be working within the 'zone of the flame' ie quite near to the flame this creates upward draughts which means things don't fall into the flask . . . . . . how do you tell if you are in the zone of the flame? Gillian Grafton tells her students that they are in the zone when the hairs on the back of their hand crisp and shrivel . . . I think she's kidding though :P :nono: Another alternative to working in the zone id to use a ring from a gas hop to create this upward draught . . . still flame the neck though

I

was planning on using clear PET bottles - is this a good or a bad idea?

I use clear glass pasta sauce jars (Dolmio and those casserole sauce jars :sick: ) which are fine . . . after all they are going in the fridge . . . . and that little light really does turn off when you close the door . Clear pet is fine

 

[Wez]

Ideally when doing wort/yeast transfers you should be working within the 'zone of the flame' ie quite near to the flame this creates upward draughts which means things don't fall into the flask . . . . . . how do you tell if you are in the zone of the flame? Gillian Grafton tells her students that they are in the zone when the hairs on the back of their hand crisp and shrivel . . . I think she's kidding though :P :nono: Another alternative to working in the zone id to use a ring from a gas hop to create this upward draught . . . still flame the neck though

:hmm: I tought that this was gonna be easy-ish - i'm not sure I understand exactly how to do this now

 

[Aleman]

Loosen the lids of both vessels, place then near to one another and close to the propane torch flame, open the lid of the pet bottle (Don't flame it!), remove the stopper of the demijohn pick the DJ up and wave it through the flame, pour yeast into PET bottle, wave neck of DJ through flame, return to upright position and replace stopper, replace lid of PET bottle

 

[Wez]

Nice one thanks - I understand now - better to ask than feck it up

 

[Vossy1]

Ideally when doing wort/yeast transfers you should be working within the 'zone of the flame' ie quite near to the flame this creates upward draughts which means things don't fall into the flask

That doesn't mean things can't get dragged into it

Don't get me started :nono:

You can take a sanitised system (picture a baloon) put a pin prick in it (without bursting it) and the outward escaping gases create an eddy (sp) effect, drawing air from outside the system, into it, therefore rendering it non sanitised. I've seen it proven using smoke particles when working in aseptic production.

It's all about best practice...that's a fact.