Slanting yeast

[Blue-Frog]

Well After my last colony isolation last night I tried the "How soon can you hold it" test.

It seems that with my materials and methods, the loop continues to be hot for 20 seconds after removal from the flame, once it has become glowingly hot over a large area of the loop.

This supports the sense I was getting that "almost instantly" was too soon for safe use.

 

[Blue-Frog]

I am thinking about adding a few wine yeasts to my collection...

Anything one should be aware of in terms of culturing differences between beer and wine yeast?

Are White labs wine yeasts grown in wort, just like beer yeast, or do they use wine/grape juice etc.?

Are the Nutrients the same for both types of yeast or are there known requirement differences?

Humm,
I notice that the typical weight of a pkg of dry wine yeast is ca. half that of beer yeast...
What is a good pitch rate for wine ?
Is it lower than for lager, (ales?) or do wine yeast... just weigh less?

 

[NaymzJaymz]

I've been into this thread for over a year, and have made several attempts with several different yeasts. The interesting results have been in the unused slants. My first few attempts yielded slants with mold in them, to which I received replies pertaining to my pressure cooker not getting hot enough to sterilize the medium. I decided to use a roaster pan and cook my slants in an oven at a much hotter temp. The result is now I have slants that have a white growth in them, as if they had been inoculated. To what should I assign this latest failure? The medium had the lids screwed down and taped as soon as they were cool enough to touch. They were broiled at 500+ degrees for the required time. The white growth suggests wild yeast contamination. How is that possible?

 

[butterpants]

I've been into this thread for over a year, and have made several attempts with several different yeasts. The interesting results have been in the unused slants. My first few attempts yielded slants with mold in them, to which I received replies pertaining to my pressure cooker not getting hot enough to sterilize the medium. I decided to use a roaster pan and cook my slants in an oven at a much hotter temp. The result is now I have slants that have a white growth in them, as if they had been inoculated. To what should I assign this latest failure? The medium had the lids screwed down and taped as soon as they were cool enough to touch. They were broiled at 500+ degrees for the required time. The white growth suggests wild yeast contamination. How is that possible?

What about the slant lids? I'm assuming they are plastic and the tubes are glass?? I doubt you're putting plastic lids in a broiler @ 500....if not, then how are you sterilizing them?

If that's not it... care to detail your step by step method so we can critique it?

 

[NaymzJaymz]

Butterpants, the easiest way of describing my technique is to say that I've followed the directions in this thread. I did indeed put the plastic lids in the covered roasting pan I used! Naïve perhaps, but they didn't melt. I would like to know how I got what appears to be wild yeast contamination when the lids were screwed down and taped as soon as they were cool enough to handle!! Thank you!!

 

[butterpants]

Sounds like you need to buy a sterilizer/autoclave. Apparently you're filthy!

 

[jason.mundy]

My gut reaction would be to say that your pressure cooker was not getting the media up to the 15 PSI. All the biological were not killed and grew once back down to room temperature.

I do not think that your media reached oven temperatures as long as they still had moisture inside of them. You can only sterilize dry items in the oven. Water will keep your temperature down to 212F where it is in contact.

 

[NaymzJaymz]

Thanks Jason, I did not know that. It is still curious to me that the contamination in this batch looks like yeast growth, not mold like the previous problems.

 

[NaymzJaymz]

My latest endeavor is with WLP001, a very popular yeast as you all know. The yeast growth began quickly, but its a bit darker than any of my other attempts. The color is not the fluffy white as seen in the instructional photos, but the same tan color as the yeast in the vial(now a plastic pouch). Any thoughts? Thanks!!!!!

 

[bionut]

It's ok. The tan colour is normal.

 

[defrandj1]

What is the wort to agar ratio?

 

[Elkaybay]

Hello everyone,

Please forgive me for not having read all pages if this has been corrected, but in the first page it is mentioned that the pressure cooker should be run at a pressure of 12psi. This is less than 1 bar ==> technically impossible unless we'd be using a depression chamber, not a pressure cooker.

Or maybe this is a specificity of pressure cookers in the US, do they maybe show the additional pressure on top of the atmospheric one? (12psi would mean 14.5 psi (1 bar) + 12 psi)?

Anyone can help clarifying this?

Thanks!

 

[MichaelBrock]

Or maybe this is a specificity of pressure cookers in the US, do they maybe show the additional pressure on top of the atmospheric one? (12psi would mean 14.5 psi (1 bar) + 12 psi)?

Yes, the 15psi is in addition to the atmospheric pressure (so it maintains a 15 psi difference from atmospheric pressure). I am not familiar with pressure cookers outside of the United States but I would have expected all pressure cookers to work this way.

Edited to add: browsing around Amazon.co.uk and it's clear that the same is true in the UK as well. Pressures indicated are gauge pressures (difference with atmospheric pressure). In a site discussing safety reguations for pressure cooking it points out that the EU rates pressure cooker pressure in bars, which is by definition a gauge pressure. So you now you have me curious! Have you seen a pressure cooker which indicates pressure as an absolute pressure?

 

[Elkaybay]

My pressure cooker simply doesn't have a gauge

Thanks for the explanation! I already see a flaw with these differential valves, your pressure cooker won't work the same at sea level and at a 3000m altitude, when indicating 12 psi in both situations

Enough off topic. I'll start slanting my yeast next week! I hope I don't contaminate anything. Thank you very much for the wonderful introduction!

 

[butterpants]

I'm at 7000'

If you figure it out I'm supposed to hit 18psi for 15 minutes but I'm always wary of too much pressure. If the media I'm sterilizing can handle it without too mich degradation (agar or pH issues, off the top of my head) you can do the lower 15psi just for 30 min.

 

[defrandj1]

Hello all,



I have been slanting yeast for a couple months now, and earlier today I came across an article about storing yeast in sterile Distilled water versus on a slant. The benefit being the ability to store for much longer periods of time without refrigeration. The thought being that the yeast just go dormant having to food source- ergo, not mutating.



Does anyone use this method? Any other thoughts?

 

[butterpants]

I personally think storing in sterile water is inferior to slanting which is inferior to freezing at - 80.

You have to pick the method you can afford and the technical level you're comfortable with.

Eureka Brewing's blog has a nice writeup on sterile isotonic saline yeast storage. Just google for it.

If you're already slanting (successfully), going with water storage is a step back... in my (and many others) opinions.

 

[Jukas]

So I'm just starting to get back to brewing after a couple years away and my slant library is pretty neglected. I'll just toss the common stuff like wlp001 and start over, but I have some slants that id prefer not to lose like harvested Conan and Bells.

The slants are looking a bit ragged and don't have that super nice white creamy look anymore.

I was thinking about plating out from these slants in an attempt to grow a new colony to reslant from, but looking at them are they too far gone?

View attachment ImageUploadedByHome Brew1450761533.757487.jpg

 

[butterpants]

2012? I'd start over

 

[brewski09]

What do you have to lose by trying?

 

[butterpants]

You could culture up a bunch of strains with a lot of drift/mutations. Not a good idea for your mother culture.

I'm not saying it's all dead, I'm saying you don't want that yeast.

You could run trial fermentations on all of the strains to see if attenuation, floculation, flavor compounds and what not are where they should be.... but that's a lot of work. I'd just rebuy or trade to replenish my stocks.... but time to me is more valuable than a 7$ smack pack.

You might be able to craft a deal with a local homebrew owner and buy his culled packets of yeast for a discount. There may be viability issues in a 6 mo old smack pack but that's an issue for brewing, not isolation and slanting. There should be minimal genetic drift and plenty alive in 6mo if the packs were stored properly.

 

[brewski09]

You could run trial fermentations on all of the strains to see if attenuation, floculation, flavor compounds and what not are where they should be.... but that's a lot of work. I'd just rebuy or trade to replenish my stocks.... but time to me is more valuable than a 7$ smack pack.

For the bottle cultures it's worth a shot and doesn't take that much time to do it. Presumably he'll be making new plates anyway so just make a few extra and then a master batch of starter wort and see how the yeast off the plates perform in the real world.

I agree on the standard strains that just getting fresh yeast is better than reslanting the old stuff.

 

[GQT]

Gentlemen, a quick question:
I by mistake sterilized a ton of vials for slants with 1030 gravity wort instead of 1040 as generally recommended. I hate the idea of redoing the whole thing.
So, will it do - or will it be too risky as the yeast might not have enough nutrition?

Thanks everyone

 

[butterpants]

You're fine

 

[butterpants]

oops, this was for another thread....

 

[Blue-Frog]

Does the stirring action affect the way 100~500ml starters look and behave?
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any one using WL036 from a slant to make a starter?

I am a newbi at slant to starter propagations...
The yeast is certainly increasing in number as there is a nice white layer of new yeast after cold crashing.... but, 036 is supposed to be a top cropping yeast... I am using a very gentle stir plate that keeps the surface slightly moving, and I got a finger thick layer of bubbles between say 12 and 24 hrs, but then it went away.

Very few and infrequent bubbles could be seen rising to the surface, but for the most part, it seemed to be inactive.

It is hard for me to form a good question... help?
humm, what does a top fermenting yeast look like when going from slant to say 500 ml?

Will a top yeast cake form even with stir plate action,
or will it look the same as a lager yeast propagation?

Is the yeast bubble head cake I observed for a few hours under stir plate activity, karausen, or just foamy wort bubbles?

I did an 830 prop at the same time, and its bubbles were much more "normal fermentation" like... (i.e. vigerous), but the 036 was stelth-like, producing lots of cells but not so many obvious tell-tale bubbles.

Anyone have a picture of your 036 starters starting up?

 

[butterpants]

I don't think there's a strong correlation between lack of a kreusen in a starter and it not producing in log phase....

Some starters seem to get super foamy, some not.

When I think angry top croppers, my mind goes to 3787. That god damm yeast will fill 5 gallons of head space in a 10 gallon fermenter in 3 days.

That said, its starters always show lots of activity for me..... virtually any volume.

Apples to oranges but a perspective.

 

[jason.mundy]

Gentlemen, a quick question:
I by mistake sterilized a ton of vials for slants with 1030 gravity wort instead of 1040 as generally recommended. I hate the idea of redoing the whole thing.
So, will it do - or will it be too risky as the yeast might not have enough nutrition?

Thanks everyone

1.030 will do. Mr. Malty says that starter wort should be between 1.030 and 1.040... So 1.030 for your slants should work.

http://www.mrmalty.com/starter_faq.php

 

[Alucard1983]

Be leave it or not I did some slanting 2 years ago... I moved and got ride of most of my washed yeast. I used 3 vials to make a new started... it's still alive.. so I'm gonna get rid of my slants and start again

 

[GQT]

A question out of mere curiosity, what is your favorite slant size?
20 ml tubes I normally use are to my taste a bit too long and I don't feel comfy inoculating them with the long and too flexy loop.
10 ml size would be ideal to my feeling but will that mean I'm not giving enough food to the yeast? (a slant in a 10 ml tube will hardly have anything more that 2-3 ml wort).
I'm soon going to order a new pack of tubes, so need to decide the size.
Thanks everyone!