[Thirsty_Monk]

I just made my supply purchase at http://cynmar.com.

Code: [Select]

12030895  GLASS ALCOHOL LAMP w/CAP, 4oz      US$3.40
CHA80228  DEHYDRATED AGAR POWDER, 30g      US$8.25
11527906  CLEAR GLASS VIALS w/AUTOCLAVABLE CAP, 12ml 12/PK      US$5.00
11527908 CLEAR GLASS VIALS w/AUTOCLAVABLE CAP, 16ml 12/PK US$5.75
13225101 NICHROME INOCULATING LOOP, 25 GAUGE WIRE, 8" TOT LENGTH US$1.50
13225110 NICHROME INOCULATING NEEDLE,25 GAUGE WIRE, 8"TOT LENGTH US$1.40
12030036 TEST TUBE BRUSH, WHITE NYLON, 3"BRUSH, 8" TOTAL US$0.70
13220697 GLASS PETRI DISH, 75x15mm,10/PK US$7.25

Kai and his "Yeast culturing gear" http://braukaiser.com/wiki/index.php?title=Yeast_culturing_gear was very helpful.

I also have "First Steps In Yeast Culture"

read "Yeast Propagation and Maintenance: Principles and Practices" http://maltosefalcons.com/tech/yeast-propagation-and-maintenance-principles-and-practices
and listen yeast culturing episodes on Basic Brewing.

Anything else I should be aware of?
Thank you

[Hokerer]

Anything else I should be aware of?

30g of agar powder will last a good while but, once you do use that up, if you have a local Asian food store, you can usually get 25g of agar powder for about a buck twenty-five.

[Kaiser]

Anything else I should be aware of?
 

Keep a back up (dry yeast for example) on hand until you are confident.

Yes, agar from those lab places is expensive. I have yet to go to an Asian food store for that. I couldn’t get it at a health store.

Kai

[a10t2]

30g of agar powder will last a good while but, once you do use that up, if you have a local Asian food store, you can usually get 25g of agar powder for about a buck twenty-five.

Making your own from gelatin and DME works perfectly well for me, and I get some peace of mind from culturing the yeast on a maltose substrate.

[mrdrysdale64]

30g of agar powder will last a good while but, once you do use that up, if you have a local Asian food store, you can usually get 25g of agar powder for about a buck twenty-five.

Making your own from gelatin and DME works perfectly well for me, and I get some peace of mind from culturing the yeast on a maltose substrate.

What proportions of gelatin and DME do you use? I assume you mix and then autoclave or put them in a pressure cooker? I need to try this. I have been kicking around the idea of culturing for a couple of years now. This forum is getting me motivated to do so many things! 

[Thirsty_Monk]

Greg Pietsch recipe:
    * 100 grams H2O
    * 1.5 grams agar
    * 1.5 grams Fermaid K
    * 12 grams light DME
http://saccharomycessafari.blogspot.com/2009/08/today-im-making-up-some-new-blank.html

Kai's recipe:
    *  100 ml wort
    * 3-4 g agar
http://braukaiser.com/wiki/index.php?title=Making_Plates_Slants

Maltose Falcons:
1.5-2.0 grams per 100 ml liquid
http://maltosefalcons.com/tech/yeast-propagation-and-maintenance-principles-and-practices

[Hokerer]

Kai's recipe:
    *  100 ml wort
    * 3-4 g agar
http://braukaiser.com/wiki/index.php?title=Making_Plates_Slants

This is the ratio that works best for me (4% that is).  I find it easier to squirt 5ml of wort into as many of the 12ml vials as I want slants.  I then weigh out enough agar to come out to about 4g for every 100ml.  Divide it up by eye into equal portions (and hope nobody walks in while I'm pushing white powder around with a razor blade) and dump a portion into each vial.  Shake it up good and then pressure can them.

If I mix in the agar first, it starts to set before I get all the mixture measured into the vials and if I use less than the 4% ratio, my slants "slump".

[Kaiser]

If I mix in the agar first, it starts to set before I get all the mixture measured into the vials and if I use less than the 4% ratio, my slants "slump".

That approach works well for me. But the solution has to be somewhat hot to remain liquid.

Kai

[Thirsty_Monk]

Thank you for advice about solid media.

Any advices about streaking yeast on petri dishes?
Some people suggest to:
Sterilize inoculation loop,
Get yeast sample,
Streak the whole plate,
Sterilize inoculation loop.

and some people suggest:
Sterilize inoculation loop,
Get yeast sample,
Streak 1/3 of plate,
Sterilize inoculation loop,
get another yeast sample,
Streak 1/3 of plate,
Sterilize inoculation loop,
Streak 1/3 of plate,
Sterilize inoculation loop.

Where would I use inoculation loop and where would I use inoculation needle?

[Kaiser]

Any advices about streaking yeast on petri dishes?

give different approaches a try. Nowadays I simply keep streaking many lines next to each other. At some point the spead of cells gets so sparse that you get nice single colonies. Re-sterilizing the needle between streaks or repeated dillution in drops of sterile water sounds cool but is way to much work for me. In addition to that it increases the time the plate is exposed to the air which is something I try to minimize.

Where would I use inoculation loop and where would I use inoculation needle?

needles are for stab cultures and streaking plates. loops are for picking colonies, scraping lawn and inoculating slants. At least that's what I use them for.

Kai

[hankus]

Here's something that is related to the culturing topic-harvesting yeast
I have begun serious yeast ranching after rinsing and after washing a yeast cake realized that when I tilted the carboy I would be pouring through the crud that had built up on the carboy walls and neck so I came up with a clean transfer system which MAY work for top cropping
I have a 8" segment of SS tube from a cut off dip tube which I immerse in a bottle of boiling water and let it sit there loosely covered with AL foil until the bottle cools.I attach one end to a hose (PURGED with hot water) which then goes to one of 2 tubes in a #12 stopper plugging a sterilized mason jar.The other tube is connected to a hose ending in a harbor freight hand pump-about 6 bux.when HF pump pulls on the system the vacuum created draws and the clean SS tube picks up the goods in a relatively clean fashion and delivers to the Mason jar(s).
If someone tries this for top cropping please report back

[roffenburger]

Thank you for advice about solid media.

Any advices about streaking yeast on petri dishes?
Some people suggest to:
Sterilize inoculation loop,
Get yeast sample,
Streak the whole plate,
Sterilize inoculation loop.

and some people suggest:
Sterilize inoculation loop,
Get yeast sample,
Streak 1/3 of plate,
Sterilize inoculation loop,
get another yeast sample,
Streak 1/3 of plate,
Sterilize inoculation loop,
Streak 1/3 of plate,
Sterilize inoculation loop.

Where would I use inoculation loop and where would I use inoculation needle?

If you are looking for purity, use the second method. This is streaking for isolation. Streak your first 1/3, sterilize (and cool)  your loop. Then make a couple passes back into the first third and into the second 1/3. sterilize and repeat.
Alternatively, you can streak quadrants, sterilizing between the third and fourth quadrant.
Or...you can make one pass right down the center of the plate and then zig-zag perpendicular to your first pass all the way down the plate.
Lots of options.

If you just want lots of growth, the first method is a way to do it. You could even make a suspension and do a spread plate.

BTW, disposable plastic loops are awesome! I didn't think I would like them when I started this job (after exclusively using ni-chrome loops), but I prefer them now. Umm....I just checked the price on them, and it may not be very practical for home culturing...scratch that idea.

[Kaiser]

I found that even w/o sterilizing between streaking sections I can get good colony isolation. But then again, I never had formal microbiology training.

Kai

[roffenburger]

I actually don't sterilize between sections either

[Thirsty_Monk]

I got my stuff today.
I will be making plates and slants tomorrow.
I was surprised how small were the petri plates and vials.
I guess I will have to get used to it.