From Slant To Starter - In Pictures

[Wolfy]

The wort in the 2lt flask looks considerably darker than the other 2.

Is this just due to the depth of the wort, or a different batch?

Yep it's just the depth of the wort and probably related to the camera flash etc, all the flasks were filled with the same wort.

I did cringe at the addition of wort to the slant and scraping the yeast off, it's a waste of a good slant IMO.

Preferred method would have to be to take, asceptically, a small amount of yeast from the slant with an innoculating loop and add that to your first bit of wort. This will allow you to retain the slant for future brews/comparison tests and allow you to maintain a pure culture strain for a longer period of time.

The above comment is based entirely on there being just the one slant, if you've got a bunch of the same yeast on a shed load of slants then it's a non issue for you.

Yes, if I only had one slant I'd be much more careful, use the procedure you mentioned and probably a smaller amount of wort for the first step. However I generally make 3 or 4 slants of each yeast I have, this seems to work well for me in that I usually have 1 left after about a year when it's time to reslant that strain.
I'll be following your procedure with the (one) commercial slant I have here, someone has said that they have been reusing the same slant - just taking a small amount of yeast each time - for 4 years now.

I've always just used test tubes of yeast. What would be the pros/cons of slants over a test tube of yeast?

Test tubes of yeast would require less preparation, but I think the yeast stored on wort/agar is a little more stable and once made they are easy to handle and store.
You can also create a slant from a small sample of 'virgin' generation yeast - from a streak plate for example - and it's easy to reslant old samples so that the yeast always remains viable, with test tube storage you'd need to grow and split the yeast each time you needed to reculture it.
Splitting new packs of Wyeast into test tubes via Tony's method (or similar) is much easier (and maybe better) than using slants, but it really 'only' lets you split the pack into a limited number of test tubes, once those are used you'll need to buy a new pack.
With slants (and streak plates) you should be able to 'save' that particular strain of yeast for an indefinate period.

So how many yeast cells do you estimate you have in the final starter?

Personally, I tend not to over-complicate things in this regard, so I make some big assumptions in regard to the cell count.
I assume that since I am using small steps, a stir plate and a healthy dose of yeast nutrient, at each stage I'll get maximum growth from the yeast.
Then I let someone Else's maths do the work for me, and see what size starter is recommended by the MrMalty calculator (assuming 1 pack of yeast and maximum growth).
Assuming again that the second-to-last-step of the starter process should have about the same number of yeast cells as commercial pack/vial of yeast (I don't recall where the basis for that theory came from), I base my starter volume on what the calculator suggests - usually rounded up to the next convenient size container I have.

 

[Fourstar]

I knew someone would say that
I've been searching for the article since I posted that...there was some research that sounded convincing that concluded what I said... now just to find it

I think thats research Jamil Z and Whitelabs have undertaken. I remember hearing that.

 

[Wolfy]

yups, it melts at ~85C (although i take it to near boiling point to get it to dissolve properly) and solidifies at ~40C and it's a disaccharide polymer that isn't metabolised, making it far better than gelatine which will liquify in the presence of proteases.

Agar agar is great, when making the slants shown in the background of the photos, I usually heat it in the microwave for 30 seconds then stir to dissolve. However, I was a little impatient and shoved it in for 1min and then went to the bathroom, when I came back it had created a huge sticky boiling mess by overflowing the jug. By the time I had finished making the slants (fun stuff first clean up later) the overflowing agar mess in the microwave had solidified and the only clean up required was to literally peel off the solid wort-jelly mess in one big sheet.
The same was true for cleaning up the saucepans, jugs and syringe, while I did shove them in a sink full of warm soapy water and let them soak, the agar-wort remained as a solid mass that was easily peeled off each item.

Note: After the I add the agar-wort mixture to the test-tubes I give them a decent amount of time in the 'pressure cooker' so mixing the agar in the microwave does not really compromise the (close to) sterilization procedures required when making slants. The Geelong/Hawthorn football match was exciting to watch, so I only remembered the slants were cooking when I went back into the kitchen after the match had finished.

 

[wakkatoo]

subscribed

 

[haysie]

Wolfy, super threads, after all those slants you made....... what are ya gotta do with them?
You cant make that much beer in a year let alone drink it. The very reason slanting aint for me, I like to split, use and move on.

 

[Wolfy]

Wolfy, super threads, after all those slants you made....... what are ya gotta do with them?
You cant make that much beer in a year let alone drink it. The very reason slanting aint for me, I like to split, use and move on.

You're right, it is getting a bit that way.
But I do use about 5 slants for each new strain (duplicates for the initial culture, then 3 more once I isolate a sample, 2 of those go in the fridge and 1 is used up to make a frozen sample) so they actually get used quickly.
It's also nice to have specific yeast on hand if/when I want it - you're welcome to visit if you ever need Pacman or 1469 for example.
Slants also allow for the 'banking' of yeast that is not (easily, often or usually) commercially available (I hope to have some of the unique old-Brewtek European yeast soon, for example).

However, other than that, for many/most people splitting new yeast packs/vials into sterile tubes (as you do) works well, is easier and much less maintenance.

 

[dcx3]

Just curious if any yeast gurus have ever tried to harvest the yeast in coopers vintage ale.

 

[wakkatoo]

Just ordered some tubes, loops and flasks from ProSciTech. Only other thing now is a 2l Flask as they didn't have them and to source some agar, which I'm assuming is not a hard thing?

 

[manticle]

I think chinese grocers/food shops sell agar-agar

 

[Golani51]

Yep it's just the depth of the wort and probably related to the camera flash etc, all the flasks were filled with the same wort.

Yes, if I only had one slant I'd be much more careful, use the procedure you mentioned and probably a smaller amount of wort for the first step. However I generally make 3 or 4 slants of each yeast I have, this seems to work well for me in that I usually have 1 left after about a year when it's time to reslant that strain.
I'll be following your procedure with the (one) commercial slant I have here, someone has said that they have been reusing the same slant - just taking a small amount of yeast each time - for 4 years now.

Test tubes of yeast would require less preparation, but I think the yeast stored on wort/agar is a little more stable and once made they are easy to handle and store.
You can also create a slant from a small sample of 'virgin' generation yeast - from a streak plate for example - and it's easy to reslant old samples so that the yeast always remains viable, with test tube storage you'd need to grow and split the yeast each time you needed to reculture it.
Splitting new packs of Wyeast into test tubes via Tony's method (or similar) is much easier (and maybe better) than using slants, but it really 'only' lets you split the pack into a limited number of test tubes, once those are used you'll need to buy a new pack.
With slants (and streak plates) you should be able to 'save' that particular strain of yeast for an indefinate period.

What is Tony's method?

 

[Wolfy]

What is Tony's method?

The search function is your friend.
http://www.aussiehomebrewer.com/forum/inde...showtopic=45866

 

[Golani51]

The search function is your friend.
http://www.aussiehomebrewer.com/forum/inde...showtopic=45866

Thanks champ

 

[Bizier]

I am concerned with concentrations of nutrients, seeing as I tried to rehydrate with some generic nutrient once (wasn't thinking properly) and damaged/killed the yeast.

Can I get some advice on how much nutrient to use, say per Litre?

 

[Wolfy]

I am concerned with concentrations of nutrients, seeing as I tried to rehydrate with some generic nutrient once (wasn't thinking properly) and damaged/killed the yeast.

Can I get some advice on how much nutrient to use, say per Litre?

Are you asking about rehydrating dry yeast, how much 'yeast nutrient' to use in a starter, or if/how much you should use in the first steps of stepping up from a slant (or from a small sample of stressed yeast)?

 

[Bizier]

My understanding was that you mixed nutrient into a common wort for all your stepping purposes. I would just like to know a good amount to use for this. I understand that there are specific nutrients developed for rehydrating dry yeast, and that the generic stuff is not suitable.

 

[Wolfy]

My understanding was that you mixed nutrient into a common wort for all your stepping purposes. I would just like to know a good amount to use for this. I understand that there are specific nutrients developed for rehydrating dry yeast, and that the generic stuff is not suitable.

The usage level for the (commercial-type) Yeast Food I have is 40ppm (40g/10hl), which is about 0.1g for starter sizes.
Since I prepare all steps of the starter at the same time (and at the same gravity) I just dip a teaspoon in the Yeast Food and throw a tiny bit in.
Having said that - in theory - the first steps of the starter should be in lower gravity (1.020) wort (presumably with less nutrients) if the starting yeast is old, tired or stressed (like the sample was in the pictures at the start of this thread).

I don't have any of the nutrients recommended for rehydrating dry yeast, so I just do that in plain water.

 

[Bizier]

Cheers Wolfy.

 

[Jarthy]

hope this isn't a silly question, as I'm getting quite interested in doing some yeast farming, but does light strike effect starters?

 

[felten]

Lightstrike only affects the hop compounds, so it won't affect your starter if you aren't adding hops.

 

[Jarthy]

that makes sense. thanks felten.