Slanting yeast

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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.

Assuming you kept them I guess you have something to inoculate your agar slants then. :)
 
yeah i do, there still in 70F on the counter. i burp them every few days.. loads of co2 production but not much visible colony forces. i haven't had a chance to clean out the tubes. i finally got my agar powder and made up 36 vials and impregnated 3 for each strain i had in the refer. day 2 on the real vials shows not much yet.

1187

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1792

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alright, so i have two of one strain that now have a thin white layer across them. how long after the entire surface is covered should they be incubated? 2 weeks isn't harmful is it?


14 Dec 2009

sadly, today 2/12 were infected with mold. luckily two different strains, and it reminded me why i did 3 each strain.
 
I've read through this whole thread, and do not believe I have seen the question asked-- when using a wyeast smack pack, how would you proceed to pull a colony from the pack.

Would it be best to smack, let swell, open, pull colony. Or just open and pull?

My instincts tell me the first method, but have yet to actually use a smack pack, so do not know if that technique will actually work.
 
I've read through this whole thread, and do not believe I have seen the question asked-- when using a wyeast smack pack, how would you proceed to pull a colony from the pack.

What are you trying to achieve? If you are making a slant, you want the yeast actively growing/reproducing, so you should smack it. If you are planning ahead you can probably do this on your brew day and get your slant built as well as brew with that yeast so you don't have to depend on the yeast-cake after that first batch is racked.
 
Yes my thought, as should be obvious from the topic, is to create a slant from a smack pack.

Contrary to what you say though, whitelabs vials are not actively growing yeast-- they are inactive, that is why I asked.

The smack pack inside the wyeast pouches, in my understanding, is some nutrient/growth medium to get the yeast going... this is different than white labs vials and why I asked.

In my understanding the yeast are at the same state in the wyeast pouch as the white labs vials before you smack the "smack packet", i.e. inactive. Once the smack packet has been activated, it is now active.

Any other input?
 
I think the yeast in a smack pack are really still in the lag phase even a few hours after you smack it. My understanding is that the pack of stuff in there is more for proofing than anything else.
 
How important is the pressure cooker to produce the blank slants? wouldn't boiling the dme/ager cause it to be sanitary and if not tech. sanitary at least wouldn't the level of heat to boil it also kill all the germs? couldnt you refrigerated the blanks after filling the slants with your dme/ager mix? What exactly does the pressure cooker perform?
 
the pressure cooker creates an environment of 230-250F depending on pressure of the steam. in 30 minutes at 250F(15 psi) all known life ceases to exist. boiling would create a sanitary condition, but it still will contain some ammount of yeast spores, etc that will pose a problem if given long enough.
 
A quick comment on incubation. The lids of the media should be left cracked open for proper air flow. The yeast need a gas exchange when growing. I have down 10+ cultures this way and only one has gotten infected with ants.( no mold or bacteria). If your having troubles with mold it could be from you hand touching the lid when you " burp" your media.
source: microbiologist ( I'm not one know a few at work)
 
I have been slanting for a while using gelatin i made up an original 25 slants and just inoculated my last 5 with Pacman i harvested from a couple mocha porters I have a healthy yeast colony in each but the gelatin is starting to deteriorate ( have liquid on the bottom )with the yeast chilling in that they have been in there for 3 days can i reslant onto newly made slants with agar or should i put my self thru the pain of having to drink a shakspeare stout or 2 because it is so rough!!!:tank:
 
I have had this happen to me a few times. The problem fixed it self when I left the slants cracked open while inccubation. I know scary right? I was real nervous to do this at first but with the yeast growing on there it creates a postive pressure. And once the yeast take over its a bit harder for bact. mold and what not to get a hold.
 
How important is the pressure cooker to produce the blank slants? wouldn't boiling the dme/ager cause it to be sanitary and if not tech. sanitary at least wouldn't the level of heat to boil it also kill all the germs? couldnt you refrigerated the blanks after filling the slants with your dme/ager mix? What exactly does the pressure cooker perform?

You need to use the pressure cooker because common bacteria and mold spores won't be killed by a boil. It's a numbers game.. when you are building a starter from a tube or pack with 100B cells vs. a slant which will grow up to about 10M cells that is a huge difference in ratios. Even a few spores will have a chance to grow and will sour your beer.
 
provided the slant doesn't dry out during that time.

I usually let my slant vials sit for 2 weeks before tightening the caps and storing so they have plenty of time to dry out. I went on vacation and left some harvested Sierra Nevada yeast out for three weeks, that was obviously too long to incubate because three of four had grown to the point gas pushed the entire slant out of the vial. :eek:
 
Don't worry about drying your slants. You're just risking infection. My slants have some liquid condensate but it doesn't interfere with yeast growth. After inoculation of a slant you should replace the cap but do not tighten to seal. Let incubate for 3-5 days at ~80F until satisfactory yeast growth occurs, then seal tight, put in a plastic bag, and refrigerate. The reason for the incubation period is to build a colony and expose contaminants.
 
So I noticed that my slant I just made have about a tiny drop water in them. I think they'll be okay.
 
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Wanted to show you guys the slants I made with the help of this thread. Im leaning one out on the shelf to see if anything grows. I hope not. Thanx again this place rocks:rockin:
 
Krops13

Good pics... And nice use of the coat hanger to make your slant. It looks like that angle gave you a lot of surface area inside the tube.

It doesn't look like your slants are in glass. Is this true?

Did you run them through the pressure cooker?

If they are autoclavable, what was your source.

Thanks, Jason.
 
They are glass. I prossesed them at 13-14lbs for 15 minutes. I pit a plastic plate in there with the slants but it melted.
 
If you let the vials cool a little too long, such that the Agar/DME solution starts to solidify before it is stored at an angle, can you reheat the vials in the pressure cooker for another 15 minutes to return it to a liquid form? Or should you empty the vials and start over?

Thanks!
 
I don't have a small scale and am having trouble measuring the 2.5 grams of agar.

I used 1/2 teaspoon and my agar hasn't set after about 12 hours.

Anybody know the volumetric equivalent of 2.5 grams of agar (e.g. 2.5 ml, 5 ml, etc).

Thanks!
 
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.

I wouldn't use regular Jello. Try Knox or some other brand of unflavored, unsweetened gelatin. Let your wort provide all the nutrients. How did they turn out after you waited another day?
 
I wouldn't use regular Jello. Try Knox or some other brand of unflavored, unsweetened gelatin. Let your wort provide all the nutrients. How did they turn out after you waited another day?

it was a complete failure:

melted at room temp
very little growth (was impregnated in media)
co2 created pockets in media
media moved around in vials
a complete pain to clean the vials
was a tricky ratio of jello/dme

pictures here

https://www.homebrewtalk.com/f163/slanting-yeast-133103/index3.html#post1730057
 
I don't have a small scale and am having trouble measuring the 2.5 grams of agar.

I used 1/2 teaspoon and my agar hasn't set after about 12 hours.

Anybody know the volumetric equivalent of 2.5 grams of agar (e.g. 2.5 ml, 5 ml, etc).

Thanks!

Have you considered a low-end reloading scale? Ammunition reloaders work in 0.1 grain (or 0.000228571429 ounce, or 0.006479891 gram) measurements.

Here is a low price, low tech, high precision scale. Accurate to 1/20 grain, allegedly. It will only measure up to about 1/4 ounce, though.

For a few dollars more this one is digital, and will measure up to about 3.5 ounces.
 
Would I be correct in assuming that the pressure cooker provides a means of sterilizing both the media and vials?

I am thinking about boiling the media and funneling it into the vials. Then I'll put the filled and partially capped vials into a beaker that will be placed into a boiling water bath. I will cover the bath (pot) so as to allow the steam to make contact with the vials. This should be sufficient for sterilizing the vials, right?

-or-

Could I simply boil the media and funnel it into the vials and then place the partially capped vials into a stove for a period of time? Like a ghetto autoclave?

Bottom line is that I do not own a pressure cooker, but there should be alternative means of successfully sterilizing the media and equipment.
 
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