Splitting - Slants - Plates

[MHD]

Bringing together a few topics here to ask some basic questions about the benefits versus the costs (ie effort) with a few of the methods...

Now first I ask: How long do people think a split yeast (fresh) pack will keep under sanitised water in the fridge?

Now as to slanting: What are the benefits of slanting (Growing yeast on a slanted agar mixture in a test tube) versus storing the liquid yeast under water? or is slanting just a way of propigating more yeast from a microscopic sample from a master yeast?

And I can kind of see the benefit of plating, ie being able to pick a colony, but how do you know if it is a colony of yeast versus a colony of infection or some other wild yeast?

As far as I can tell, plating and slanting is so you almost never need to buy yeast again while splitting basically decreases the cost? right??

 

[Airgead]

Bringing together a few topics here to ask some basic questions about the benefits versus the costs (ie effort) with a few of the methods...

Now first I ask: How long do people think a split yeast (fresh) pack will keep under sanitised water in the fridge?

Now as to slanting: What are the benefits of slanting (Growing yeast on a slanted agar mixture in a test tube) versus storing the liquid yeast under water? or is slanting just a way of propigating more yeast from a microscopic sample from a master yeast?

And I can kind of see the benefit of plating, ie being able to pick a colony, but how do you know if it is a colony of yeast versus a colony of infection or some other wild yeast?

As far as I can tell, plating and slanting is so you almost never need to buy yeast again while splitting basically decreases the cost? right??

[post="125904"][/post]​

MHD

Splitting basically splits the cost of 1 pack/vial of yeast across multiple brews. Plating and slanting mean you keep your yeast long term and only ever have to buy each strain once.

The diference between plating and slanting is storage time. A slant will last at least a year in the fridge, probably 2. A plate will only last a few months and is much more suceptable to infection. Storage under sterile water apparently has similar results to slanting but can take more room as people tend to use bigger tubes and as far as I can see make it harder to get the yeast out of storage - you have to get it out from under all that water rather than just scraping some off the slant.

I use both plating and slanting. When I get a new yeast of unknown origin/cleanliness I will plate it out then select a single clean colony to put in slants. All my long term storage is on slants.

I keep a master slant for propogating other slants and make 4 or 5 working slants. When I do a brew I just fill the tube with the starter wort, shake and decant that into a test tube to get the starter working. I use a whole slant per brew rather than scraping up a little yeast from the slant and starting with that as I feel that opening the slant multiple times and taking sample can leave you open to infections and by using a whole slant the starter starts faster. Making new slants is pretty easy and quick. I just wait till I've run out of working slants then make a new batch of 5 from the master slant. The advantage of doing it this way is that you are always propogating your working slants from a first generation sample which keeps mutations down. If you propogate from your working slants your generation count will go up and things can start to mutate. If the master gets infected or gets too old I will promote a working slant (which is only second generation) to master and keep going making third generation slants. I have read that 6 generations is about all you will get before the yeast mutates too much so once the master hits 6th generation (by my calculations in 2017) I will just buy that strain again and start over.

Cheers
Dave

 

[berazafi]

Great post

Having aquired all the equipment to be able to produce slants, i now understand the reasons why i would want to do this

 

[Airgead]

Great post

Having aquired all the equipment to be able to produce slants, i now understand the reasons why i would want to do this

[post="125962"][/post]​

That's very homebrewer isn't it. We always end up buying some gear THEN wondering what we can do with it. :beer:

Cheers
Dave

 

[Sloth]

On the topic of splitting and culturing, i am currently splitting my liquid yeasts and storing them until needed. I am interested in yeast propagation techniques and the use of slanting.

Is it who somebody here to make some form of guide on how the use the slant/plating technique with lots of pics or at least point me in the direction of where i can find the info?

I think this would not only benefit me, but a whole bunch of brewers out there.

Cheers, Sloth. :beer:

 

[Airgead]

On the topic of splitting and culturing, i am currently splitting my liquid yeasts and storing them until needed. I am interested in yeast propagation techniques and the use of slanting.

Is it who somebody here to make some form of guide on how the use the slant/plating technique with lots of pics or at least point me in the direction of where i can find the info?

I think this would not only benefit me, but a whole bunch of brewers out there.

Cheers, Sloth. :beer:

[post="126124"][/post]​

Sosman has a good guide on the Brewiki.

That should get you started.

Cheers
Dave

 

[MHD]

good replies!

What is the procedure for slant to slant transfer?

 

[Airgead]

good replies!

What is the procedure for slant to slant transfer?

[post="126766"][/post]​

Easy

Sanitise work area (wipe down with meths).

Flame innoculating loop until it glows red.

Open innoculated slant in the rising air column of the burner flame.

You can wipe down the lip with meths if you are paranoid but I just take care not to touch the lip or sides. if I do I re-flame the loop.

Use loop to pick up a little yeast (the loop cools as soon as it touches the agar in the slant, just make sure you scrape up some yeast away from the toasted stuff where the loop made first contact).

Replace lid on slant.

Open non innoculated slant in the rising air column

Again, wipe down lip or just don't touch the sides

Rub the loop across the surface to innoculate the slant

Cap slant

re-flame loop.

Label slant

The key things are - don't touch the lip or sides with the loop. Try to do everything in the rising air column of the burner as this pushes dust/bacteria etc away. When you open a slant, don't put the lid down the trick is to hold the lid with your lindex finger and thumb while you do the transfer then pop it back on. It takes a little practice but its easy enough.

Cheers
Dave

Edit: wrong finger...

 

[MHD]

Sounds easy!

Another quick Q, Do the slants need any liquid over them?

 

[pint of lager]

Slants have no liquid in them. They are test tubes about 1/3 filled with agar and allowed to cool on a slant to maximise the surface area of sterile agar in the test tube.

Go to Sosman's site, it was listed earlier in this thread and also in his byline. There is a comprehensive list of sites there, which include lots of yeast propogation information.

Handling very small amounts of yeast require special techniques, just like Airgead has just outlined.

cons:
infection and mutation city
extra time
exra equipment (cost, storage)
from micro sample to pitching quantity is about a week so you have to plan ahead

pros:
once you have the setup, you have lots of varieties of yeast available at almost zero cost

As the quantity of yeast handled is very small, the risks of infection go way up. If you are not prepared to pay attention to detail, write good notes, label every test tube and be sterile rather than sanitary, your yeast farm will fail.

It is very important if contemplating splitting, slanting or storage under sterile water to do lots of reading and research before embarking.

For instance, you have a plate of yeast and select just one colony, the biggest and fattest because you believe it is the healthiest. The biggest colony is a mutation, and using it will give you bad results and wreck your brew. One brew of failed beer is costing you heaps in time and ingredients. Bad results include, under or over attenuation, slow ferment and weird flavours.

 

[Trough Lolly]

If you're interested in reading more about yeast plating and slants, in addition to the wiki info, check these out:

A yeast propagation primer for larger brew setups but still has good reference info...
A yeast management primer from the same website...
Yeast lab procedures
Brewers Lab Handbook - Franklin Homebrewers...
and my favourite:
The Brewers' Laboratory Handbook (pdf)...
Cheers,
TL

 

[Trough Lolly]

P.S. Excellent post, PoL...

 

[MHD]

So do you have a microscope?

 

[Airgead]

*Excellent post snipped*

It is very important if contemplating splitting, slanting or storage under sterile water to do lots of reading and research before embarking.

[post="126793"][/post]​

I couldn't agree more.

If its just a cost issue, $15 or so per brew for a new tube of yeast really isn't *that* much. Especialy if you save some slurry and re-pitch for your 6 generations. Doing it that way you can get it down to around $2/brew. The disadvantage of course is that slurry has a fairly short shelf life so you need to use that strain of yeast quite a bit. You really can't keep too many varieties on the go with this technique unless you brew every day. Its good for keeping your favorite strain but not the ones you uses every so often.

Splitting saves you even more money especialy when combined with re-pitching slurry. If you split a pack into 4 then re-pitch each one 6 times there's 24 brews so around $0.50 or so per brew. Kept under sterile water each batch will keep for a fair while so you can afford to keep more varieties on hand. You do need to start being very careful with sanitation/sterilisation though.

Slanting, from a money perspective really isn't that much more efficient than splitting. Sure I can get hundreds of slants out of my initial tube and reduce my yeast cost to less than 1c/brew but $0.50/brew isn't that much of a saving. For me its the storage time that is the reason for using slants. Each slant will keep for a year or two so I can keep dozens of strains on hand. Even if I only use a strain once a year I can still keep it in the library. Using stabs (something I am experimenting with) you can apparently keep yeast alive and unmutated for 5 years or more. I can also keep strains cultured from commercial brews (like my coopers strain) which gives me more options. On the dowbnside of course it is a hassle and you do need some fairly extreme hygene.

For me its all about convenience and I'm the sort of wierd obsessive freak that is prepared to go to huge lengths for that. I love being able to go to my fridge and have ALL the yeasts I ever use on hand for immediate use. No more calling the LHBS and waiting for it to come in. I know that within 4 days I can have a starter of any yeast I have ever used ready to pitch and I like that.

Cheers
Dave

 

[Airgead]

If you're interested in reading more about yeast plating and slants, in addition to the wiki info, check these out:

A yeast propagation primer for larger brew setups but still has good reference info...
A yeast management primer from the same website...
Yeast lab procedures
Brewers Lab Handbook - Franklin Homebrewers...
and my favourite:
The Brewers' Laboratory Handbook (pdf)...
Cheers,
TL

[post="126797"][/post]​

Good links TL. Here's another I found useful - http://www.maltosefalcons.com/tech/MB_Rain...t_Culturing.php

Cheers
Dave

 

[MHD]

Actually that first one, TL, is the best... very nice..