Slanting yeast

mordantly said:

i can only find gelatin in 1oz packaging. will regular gello work? thicker of course.

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I have heard it will work although I have not tried it.

it looks like you penetrated the surface of the medium at innoculation time vs swiping the surface?

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Yeah I just poke it 5-6 times.

11-8-09

made the following "jiggler" ratio. (jell-o reports 76g sugar in 3oz):

1 3oz package lemon jell-o
1 tbsp dme
5oz water

got 5 tubes each of ~20ml firming in fridge. gonna try to put some yeasties in them tomorrow using my homemade nichrome wire loop.


11-09-09

it seems if you put this "slant" in the fridge to set, once at room temp there is moisture/softening of the media. resting at room temp till nearly firm so far has absorbed the moisture.

i made some slants yesterday .most of the liquid slanted but there is still a small amount of liquid that wont slant.
do you think i should start over?

dooksh said:

i made some slants yesterday .most of the liquid slanted but there is still a small amount of liquid that wont slant.
do you think i should start over?

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You really want solid media for storage, if the slants aren't solid you need to use more agar and try again. I have some slants that got watery after storage, they still seem to be building up OK but they were solid when I cultured the yeast, for those I will be tossing them pretty soon because I don't expect them to be viable nearly as long.

how will yeast respond if taken from a washed starter @ 40F and innoculate a slant at 65F?

mordantly said:

how will yeast respond if taken from a washed starter @ 40F and innoculate a slant at 65F?

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Don't think it would be a problem, but I wouldn't try it unless the yeast are first generation or you streak a plate to make sure it isn't contaminated before using the slants.

Would a pressure cooker that only does 10 psi work sufficiently? It seems like a lot of the new cheaper models don't go to 15psi.

cmcnair1 said:

Would a pressure cooker that only does 10 psi work sufficiently? It seems like a lot of the new cheaper models don't go to 15psi.

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You need at least 12 PSI above ambient pressure to reach the recommended 240*F for canning. You could probably get away with it... but I wouldn't try.

Sacc,
I've heard of people dumping some boiled/cooled starter wort into a couple of cultured slants to begin their starter. They would use a sanitized loop to mix the yeast and wort and dump that solution into their flask and place on a stir plate. They would re-cap the emptied tube and allow the culture to re-grow on the same agar/slant.

Does this sound o.k.?

Hugh_Jass said:

Sacc,
I've heard of people dumping some boiled/cooled starter wort into a couple of cultured slants to begin their starter. They would use a sanitized loop to mix the yeast and wort and dump that solution into their flask and place on a stir plate. They would re-cap the emptied tube and allow the culture to re-grow on the same agar/slant.

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Yep, you should do this if you don't have canned wort. Reason is, if the wort isn't absolutely sterile, you could get hosed by bacteria in the slant to 250mL step because it's a large one and the lag time is long (especially if you don't have a stir plate).

Thanks Sacc,

Is using multiple slants to increase the initial cell count?

I have 5 slants of a few different varieties. Each have a good size culture. Should I use all 5 when beginning a starter or just a few?

I have been using only one slant. I would scrape the slant with my loop and inoculate the starter wort with the single culture.

Hugh_Jass said:

I have been using only one slant. I would scrape the slant with my loop and inoculate the starter wort with the single culture.

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I only use one slant. Making slants is a PITA, I wouldn't want to use them all up at once.

I'm sorry. I wasn't clear on my initial post.

If I dump sterile wort into a few inoculated slants, scrape the cultured yeast off the agar to get it into solution and pour that solution back into a sanitized Erlenmeyer flask, can I re-use the slant. According to another person who slants, the culture will re-grow onto the same agar. In your opinion this correct method or no?

Hugh_Jass said:

I'm sorry. I wasn't clear on my initial post.

If I dump sterile wort into a few inoculated slants, scrape the cultured yeast off the agar to get it into solution and pour that solution back into a sanitized Erlenmeyer flask, can I re-use the slant. According to another person who slants, the culture will re-grow onto the same agar. In your opinion this correct method or no?

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Oh, I suppose you could do that, though usually the slant falls apart when I add wort to it.

I'll try it next time and let you know if it re-grows a clean culture.

This thread has been very helpful. Thanks

Hugh_Jass said:

I'll try it next time and let you know if it re-grows a clean culture.

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I don't see why it wouldn't as long as everything is sterile... provided the slant doesn't fall apart.

the candle creates carbon deposits on the nichrome. maybe i need an alcohol lamp?

mordantly said:

the candle creates carbon deposits on the nichrome. maybe i need an alcohol lamp?

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Until recently I was just using a bic lighter to flame my loop and other anything else I needed. It worked fine just required a bit more planning

im sad to report, on day 5 or 6, no visible life of any kind on my three test-slants of the previously mentioned jell-o media. how long should i wait at 65-70F before i scrap the test? i think the stuff is too dry for growth.

Might as well wait a few more days. But if it's too dry, it's too dry.

My dad is a vet and he uses an alcohol lamp to sterilize his loops, use the 91% alcohol.

Using a bic lighter is OK, but using an alcohol lamp is the preferred method, as it leaves no residue.

Also, while chem lab supplies are definitely best, most can be substituted with mason jars of various sizes. Baby food jars are also apparently great and vac seal fine with the pressure cooker, although i have not tried that one personally.

For an easy and cheap stir plate, take an old computer fan (12V or 5V) and an old AC/DC converter to match the fan (12V or 5V, duh) and glue a magnet to the center of the fan blade (i used a magnet out of a computer HD, strong, small, flat). It can be a PITA to position the magnet correctly, I had an issue of the fan not working because of the misplaced magnet, and also if it's off center it will shake the rig. I found Tupperware a good enclosure for the device, and you can use cardboard to space it correctly inside. Works as a great cheap stir plate, just use a stir bar or piece of wire (less ideal). This setup has no speed settings, but you might be able to use a dimmer switch or such to do that, but no guarantees.

Searching google you can find instructions with pics and more detail.

Oh, and a note on pressure cookers. Be careful if you're getting one second hand, a bad gasket is the most likely problem, and can be fixed easily(buy new one) and does not pose much of a safety hazard, but would just keep it from pressurizing. But there is the risk of cracked/weak metal, which could rupture once it is under pressure (read: shrapnel). Visual inspection should be enough as anything likely to cause rupture should be visible.

Just please don't use an old pressure cooker blindly.

Has anyone tried this with harvesting yeast from commercial bottles? If you built up the yeast from a bottle to maybe a 150ml starter, could you then just slant as described? Obviously this would possibly be less sanitary than the pure strain from white labs, etc., but I assume it's doable?

commonlaw said:

Has anyone tried this with harvesting yeast from commercial bottles? If you built up the yeast from a bottle to maybe a 150ml starter, could you then just slant as described? Obviously this would possibly be less sanitary than the pure strain from white labs, etc., but I assume it's doable?

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I've done this numerous times, though I go onto a plate before a slant or other culture. Just recently I did it with New Glarus stone soup, though I'm not sure if the yeast strain in there is the same used to ferment the beer or just a bottling strain.

I add about 10-25ml of wort to the dregs of the carefully decanted bottle and top with foil. Then a day or two later add another 50-100ml. Another day or two later I dip my innoculation loop in the bottle and plate it out.

commonlaw said:

Has anyone tried this with harvesting yeast from commercial bottles? If you built up the yeast from a bottle to maybe a 150ml starter, could you then just slant as described? Obviously this would possibly be less sanitary than the pure strain from white labs, etc., but I assume it's doable?

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Haven't but plan to soon. My idea was almost exactly as bokonon said; build up what is left in the bottle (or two) and then spread some on petri dishes to isolate the yeast from any possible contaminants, then slant from the isolated samples.

You could cut out the petri dish part and just make multiple slants and you should be able to see if any are contaminated, but it won't be as clear as on a petri dish.

this may be a bumb ?. can i rehydrate my ec-1118 and then slant it as it were any other yeasties?

No reason why not, other than the fact EC-1118 is about $0.99 a sachet...

Another topic we were discussing in chat yesterday, is how to slant sour beer dregs.

Yeast grow best in a agar/8% wort media with exposure to oxygen, but bacteria prefer 2% dextrose media without oxygen. So, we were thinking, grow up a small culture from bottle dregs, about 100-150mL over two weeks as described, then inoculate slants of wort media and stabs of dextrose media. The slants are incubated at a cool room temp to favor yeast growth, while the stabs would be incubated over 90*F for several days since beer bugs are thermophilic. Both the slant and stab would be recultured separately, with the yeast in 10*P wort and the bacteria in 2*P dextrose/molasses, then combined when it's time to pitch. I'll be giving this a try soon with some Consecration 2x1 dregs, I'll create an extra stab and slant so I can reculture and plate each one to see how it works out.

well, obviously i need the practice. i did a fresh round on my jello slants today. i added more water and re-pressured them. im now thinking some preservative is hindering the yeast not a lack of moisture. the first round i had one that looked like a colony but was powdery. so im trying 2mL more water per slant. as well as two additional strains so i can conclusively rule out jello inside of a week.

mordantly said:

well, obviously i need the practice. i did a fresh round on my jello slants today. i added more water and re-pressured them. im now thinking some preservative is hindering the yeast not a lack of moisture. the first round i had one that looked like a colony but was powdery. so im trying 2mL more water per slant. as well as two additional strains so i can conclusively rule out jello inside of a week.

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I tried using gelatin for plates once and never had good luck. The biggest problem was keeping that at a temp to give good/quick growth (65-75) ended up with them turning back into mostly liquid.

I'd definitely recommend agar. The small packs you can get at an asian food store or health store are a couple bucks and I just found 1/4 lbs at my local health store for about $19 (which will last almost forever)

something strange is happening to my slants in incubation .
as you can see in the picture the left slant is disconnected .
what do you think is the problem (maybe to much agar agar)?

dooksh said:

something strange is happening to my slants in incubation .
as you can see in the picture the left slant is disconnected .
what do you think is the problem (maybe to much agar agar)?

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Hmmm! Never seen that happen before. I have no idea! It is kinda cool looking though :cross:

yes, the amount of water to keep jello solid was tricky to find. but even more moisture still will not allow yeast to live. i transferred colonies bigger than bb's of live yeast in there and today, they look dead. i have to get agar on-line i guess. stores are 40 miles away and i have no "legal" transportation.

DON'T USE JELLO!!!!!!!

Question for Mr Saccharomyces...

What is the benefit of doing a slant vs just streaking a plate and storing it in the freezer? In the plate method you can regrow from a single colony and it also make isolation and identification of infection pretty easy as you don't get a "glob" of yeast, rather individual colonies that are less likely top contain a significant mutation compared to a big glob (in my basic understanding).

SWMBO works in yeast genetics and I have been trying to gather some basic understanding from her but was curious if those out there that do this stuff relating to beer have a preference or see any difference between the methods.

As I understand it, plates are not good for long term storage. The large surface area causes them to dry out, and they are more susceptible to contamination due to the large surface area. Not to mention, they are more expensive than vials, and take up more room for storage than slants.

If you are concerned about testing for contamination you can always dip a loop into a slant and streak it on a plate, then isolate a good colony from the plate to build up your starter.

well i finally located some agar agar for a decent price. i have 4 oz powder form shipped to me for $14. has anyone used it?

My recipe for slant media is:

1.5% agar powder
7% DME
1% Wyeast yeast nutrient

That is by weight so if you have, say, 500mL of water you will add 7.5 grams of agar and 35 grams of DME along with 5 grams of the nutrient.

The agar powder def. works better than the stuff I got at the grocery store, which after a few months in the fridge started falling apart.

hot soup! ld carlson yeast energizer and nutrient mixed is probably similar to the wyeast stuff.

Yes. Good post. I started making slants again yesterday and will post some of my thoughts, questions, and pictures soon. Plus I haven't read all the posts yet...because I'm busy in the brew room again making mini starters to support my future yeast civilization! I made a test tube slant holder w/ cover to hold my stoppers in. The slants need to be "purged" of gas or they will blow the stopper out if I can't get to them in time so my slant holder has a lid and holds 12 test tubes.

well i did in fact have life with 1187, 1792, and ec-1118. it only took 15 days. i noticed all these bubbles forming inside the tubes. so i burped em, and sure enough i got gas! too bad there all going to die when my agar ever gets here.