What I Don't Understand About Slanting

[Bribie G]

I'm going to get into slanting, particularly to cover me for the long periods when the yeast companies deign not to supply me with varieties such as 1469 to they've done that to themselves.

Now slanting seems quite straightforward, but the big glaring issue seems to be: (typical guide to slanting )

The First Step is to make up some slants - which you'll use later to grow yeast. (I make between 20-25 with this mix) Sanitize your hands, work area and utensils.

• Boil 1 cup (250 ml) water (in a small saucepan). Remove from heat, add 15 grams of dried malt extract, and stir till dissolved. Put back on the heat and boil for 10 minutes. Remove from heat.
• Add a packet of gelatin into this "wort" and stir until COMPLETELY dissolved.
• Pour this mixture into test-tubes; Fill each about 1/4 full. Keep some empty test tubes for next stage.
• Place a pyrex jug/dish inside a large pot with lid. Place the 1/4 filled test tubes and some empty ones in the pyrex container (if you have a test tube rack which fits in your pot - this can save you some headaches as I couldn't find dishes which fit inside pots). continuation..........continuation..........

Ok hold everything there, I assume the tubes are now going to be cooked for a while, I thought that gelatine is denatured during intense heating. I take it that this isn't so?

 

[manticle]

The gelatin will presumably form a jelly after cooling on which the yeast will grow reproducible cells. Most slanting I've heard about uses agar. Denaturing shouldn't be a problem though as far as I know - you're forming a substrate on which yeast cells will survive until called upon again. Jelly is made with boiling water and still sets and is still sweet.

I myself just reserve some yeast under boiled, cooled water in sanitised test tubes with a stopper, in the fridge.

 

[mxd]

wolfy had some great picies etc.. of how to do it.

 

[Bribie G]

I'll be using agar, I take it that during steaming / cooking the tubes don't get filled up with condensed water - as they are sitting upright?

 

[AndrewQLD]

I'll be using agar, I take it that during steaming / cooking the tubes don't get filled up with condensed water - as they are sitting upright?

Yes they do Bribie, I always had the lids on but slightly loose, still got condensation inside, real pita.

Andrew

 

[Bribie G]

Thanks, yes that was 'intuitive' because that's what happens when you steam food - loose lids sounds the go. I can get heaps of agar in the Valley where I work and I understand it gives a firmer substrate than gelatine.

 

[wakkatoo]

hey bribie,

I've just started and 'slanted' my first 3 tubes of Wyeast 3068 last night. Here hoping it all went well!

I followed Wolfy's method. After the 'wort' is in the tubes, I then pressure cooked them with the lids on the tubes and the tubes standing up right in a standard pot with a Mortar, or is it pestle???, sitting on top. The wort remains liquid long enough after cooking the tubes to then lay them on their side to get the nice slant happening. Some condensation did form (1-2 drops) but I just tipped this out immediately before adding my yeast last night. I made 20 slants about a month ago and nothing has formed on the slant since then. Here's hoping the yeasties do their job now and I get some nice colonies.

Not sure if its answered your qns, but I had fun typing

edit-spellink and gramma

 

[proudscum]

The nice post man delivered my new 21l pressure cooker today and my collection of flasks fit in quite nicely.so i can start with a practice run on making up some slants just need to nip up to Footscray to get some Agar Agar.Just wish my brewery would hurry up and arrive!!!!!!!

 

[Bribie G]

I can't find Wolfy's contribution in the articles, anyone have a link?

 

[wakkatoo]

Here you are: Linky

There are links to the other two he did via this thread. Great thread and a nice bloke too!

 

[proudscum]

this is a threat i started if you look at post#16 it may be of some help.

http://www.aussiehomebrewer.com/forum/inde...showtopic=49205

 

[Silo Ted]

Agar culture substrate medium would be preferred over gelatine for this type of thing.

What I don't understand about slanting is why, for less of a pain in the butt, in brewing terms, why you don't instead just keep a small sample under liquid, and if you aren't using it for three months, make a rejuvinating starter and re-stock the cool pantry for a time when you need to activate/reproduce the sample.

But if keeping a smaller cell sample, and slanting, you would need to consider contaminants, and surely need a laminar flow hood to ensure optimum viability, without 'wild' aspects of the environment to mutate the core strain.

Science is good, but it doesn't make better beer all the time.

 

[Thirsty Boy]

because keeping yeast under liquid is just about the worst way to maintain a pure, viable, non-mutated version of the yeast you want to use. Whereas slanting is the next best option to cryogenic storage for exactly the same reasons.

 

[Bribie G]

Yes, currently I keep 500ml Schott bottles full of yeast cake in the lagering fridge and when I run out of Schotties I end up with coca cola bottles full of Irish Red or even S-189 and before you know it the fridge is looking like a Chinese Brothel, following which after six weeks or so it's a PITA regenerating some of the stuff. Also as I found out in previous cold break experiment, that lovely creamy yeast cake is probably only 30% yeast, and how much of it still alive is anyone's guess - the rest is break and dead crap and although it's not going to do the next brew a great deal of harm, slanting seems to me to be a more controlled and professional way of doing things. Sure if I'm going to repitch a very similar style within a week I'll still go the Schott bottle - but that isn't going to see me over the next 2 year wait for 1469, or 1768 (remember that one, which they eke out every few years). or Pacman or.............

 

[Pennywise]

I myself just reserve some yeast under boiled, cooled water in sanitised test tubes with a stopper, in the fridge.

Sorry, a bit :icon_offtopic: Manticle, how long have you been able to store the yeast for like this?

 

[Phoney]

Sorry, a bit :icon_offtopic: Manticle, how long have you been able to store the yeast for like this?

Im not Manticle, but i've made starters from yeast that has been sitting in sanitized urine sample jars for 18 months+.



Making Agar Slants in Picture:

http://www.aussiehomebrewer.com/forum//ind...showtopic=47107

From Slant to Starter in Picture:

http://www.aussiehomebrewer.com/forum//ind...showtopic=46262


I bookmarked em for one day when I finally bite the bullet and go down that path.

 

[RdeVjun]

Sure if I'm going to repitch a very similar style within a week I'll still go the Schott bottle - but that isn't going to see me over the next 2 year wait for 1469, or 1768 (remember that one, which they eke out every few years). or Pacman or.............

Hear hear Bribie, IMO it just isn't worth the farting around slanting strains that are available from retailers all year round, but with seasonals on slants, that 2 year wait (indeed if ever) reduces to about a week.
Yep, I do remember 1768 indeed, it is right up there with 1469 for ESBs! :icon_drool2:

 

[porky]

Hey BribieG,

We make slants all the time, have done for two years now.

Have a look here:

http://www.tigereye.net.au/bluedog/slants.html

We have 23 different yeasts on hand.

Cheers,
bud

 

[argon]

Im not Manticle, but i've made starters from yeast that has been sitting in sanitized urine sample jars for 18 months+.

From what i understand... yeast can be stored under water for a long period of time... but just don't expect the strain to be exactly reminiscent of the original culture. Slanting limits the mutation by only storing very small amounts, limiting potential characteristic drift.

 

[[email protected]]

I have been in contact with a US homebrewer who also has a PhD in microbiology and when I discussed the concept of slants and doing a yeast bank he said it is easier to manage a frozen yeast bank and that is what he does. It is the process I'm currently setting up to do. It is essentially the addition of glycerin to a water yeast blend and storing the vials in a freezer. The glycerin prevents any freezing and limited or no nutrient is present so mutation is limited compared the cryogenic storage processes the prefessionals use.

Here is a link to how it is done:

-Guide to making a frozen yeast bank-
http://www.homebrewtalk.com/f13/guide-maki...ast-bank-35891/