The Big Queensland Yeast Swap

[Hoops]

i need to pic a date for that.........next monday arvo/night??????

i need a abel assistant....hoops?

[post="75184"][/post]​

Ummmmmm that should be fine by me (as long as nothing else pops up).
I have a couple of plates ready to be innoculated so I can bring them along.

And oz - the stuff you were after (slightly off topic) is Calcium Propionate (preservative 282) which is "commonly used in bread as a mould inhibitor"

Hoops

 

[Hoops]

Batz

the main reason I am getting into it is it's fun
The thing I like about slants/streaking is you can have a shite load of different yeasts in a very small space (100 yeast test tubes would take up about a 15cm x 15cm piece of realestate in the fridge and means that you can have pretty much any yeast on hand (except blends of course).

Hoops

 

[PeterS]

i need to pic a date for that.........next monday arvo/night??????

i need a abel assistant....hoops?

[post="75184"][/post]​

If you are going to have a demo Jason, you will need an audiance. I am a willing participant. Whenever you are gpoing to have it, please PM or email me your date, time and adress.

:beer:
PeterS....

 

[Hoops]

OK I can come Monday the 5th 19th or 26th at this stage but not the 12th

 

[ozbrewer]

lets make it the 19th

 

[Batz]

Bugger !

I could make the 26th

Batz

 

[ozbrewer]

ok 19th or 26th....either is good for me

 

[BrissyBrew]

For plating my pressure cooker now has a drying cycle!
Ok I am lying just a little bit, but I now wrap my plates in alfoil then after they have had a good 20mins in the pressure cooker, I remove them and put them in the oven for about 20mins at 170*C. It also means I have nice try plates to poor the agar medium.

Does anybody have good ideas about how to get the temp just right for pouring agar, I am starting to do it my thickness yardstick. But I still pore some of my plates too hot and get a little condensation as a result.

As an aside I really love being a yeast thief. As some brisbane people may know you can still get XXXX beer draft beer drawn from wooden kegs at the breakfast creek hotel. I was wondering, first is the filtration still so fine to screen out 100% of the yeast. Second and more importantly is the beer still pasturised? And no I dont drink XXXX but would love to steal their yeast strain. I should go for a tour and keep a couple test tubes (beg for a taste of green beer)

 

[Ross]

I had always assumed the xxxx out the wooden kegs was just a cheap marketing gimmick & was the identical beer to the s/s keg, just repackaged?
On the few occaisions I've tried it, i can't honestly say it tasted any better...

 

[pint of lager]

Brissybrew, usually you cook glass plates in the pressure cooker with the agar solution already mixed up and in the plates. This way the media gets sterilised at the same time.

Make up the correct og wort, bring it to the boil, add agar, stir till completely dissolved, pour into plates, pressure cook plates. Usually you only pour prepared sterilised agar into sterilised plastic plates.

Moisture is your enemy. Unfortunately, removing the lids to get rid of the moisture exposes the plates to the air and contamination. Store all plates upside down, this keeps the moisture in the lid not on the agar media.

Agar melts at around 90 deg C, and sets at around 40. When pouring it, so long as it is still a flowing liquid, the actual temp is not important. When doing plastic plates, I remove the sterilised wort from the pressure cooker and use a glove or towel so I can handle the hot flask.

 

[BrissyBrew]

You pour your plates then pressure cook. I would have thought that would result in boil overs on your plates, and way too much condensation on the plate.

Anybody else pressure cook their plates with medium inside?

I pressure cook my slants with the medium inside but not my plates.

My procedure
1. Pressure cook my plates for 20-30mins at 15psi
2. Remove plates (wrapped in foil) and place in oven at 170*C for 30 plus minutes. Turn oven off and allow to cool slowly.
3. Pressure cook my agar medium.
4. Take cooled (around 50*C) medium and pour plates.
5. Once plates are set, turn upside down and store in steralised container or wrap in foil.

I then may plate straight way (if in a hurry) or allow my plates to sit for a few days just to see if anything grows first.

I then plating using the quandrant method.
I have tried working below the flame, above the flame and to the side of the flame with different degrees of success.

I have stopped flaming the loop after each quadrant and just dragging my loop in a zig zag motion and lifting it to cross over a quadrant and to plate the field. I can isolate single colonies without reflaming, and dont have to introduce the loop to the inside of the plate so many times.

I am currently getting something stange growing after a week or more in 1 out of 6 plates on average. What are other people getting?

I am still convinced I need to improve my technique to improve the success ratio.

 

[BrissyBrew]

I have now tried preparing my plate in the pressure cooker. It seems to have worked however I find the level of condensation unacceptable. However I have been thinking that it maybe reduced if I:
1. Cool slowly, hoping some of the condensation falls back into the agar solution before it sets.
2. Tilt from side to side when hot (hoping it will flow back down the sides, however that may leave a big mess)

Alternatives:
- improve my technique with slants, so I can isolate single colonies that way, but it is crowded.
-forget about my petrie dishes and plate in a 250ml schott bottle. (pressure cook the lot due to the shape you dont get any condensation, I haved tried this, it is a little tricky to plate as I find it hard to hold the lid and tilt the bottle on the side as to work over my flame. I could however just leave it flat and take the lid off.

Anyways is the yeast swap still going ahead?

 

[ozbrewer]

I
Anyways is the yeast swap still going ahead?

[post="76977"][/post]​

yeah, have we decided on a date?

 

[pint of lager]

Brissiebrew, condensation is the enemy.

Cook your plates up, when cool enough to handle and they are set, wrap each one in plastic clingwrap, or seal with electricians tape, or, if you are lucky enough to know someone who works in a lab, they have a special membrane/gladwrap style product they use.

Store the plates upside down, all the moisture sits in the upturned lid.

When you go to streak the plate, keeping the plate inverted, remove the wrap and the part with agar in it, flick the lid to remove moisture, place on your sanitised workbench, streak and reseal. Always store upside down.

If you have not used enough agar, or allowed it to mix thoroughly and dissolve when making the media, the agar may fall off the petri dish when stored upside down. Otherwise, prepared plates, both streaked and unstreaked are stored upside down. This way, excess moisture does not fall onto the plate.

 

[BrissyBrew]

pint of lager

I have tried pressure cooking the petrie dishes with reasonable success. Yes there is now a big condensation problem, however as they are stored upside down, I can live with the condensation (hey its only water, and it should be sterile, yes it you go to plate or pick out a colony you might have a drop of water fall, but I can live with that. I dont rap in glad wrap, I use aliminium foil instead (I think it breaths a little so the plates dry out a little bit (which is not a problem considering I have condensation problems. The only thing I dont like is the agar solution is on the lid, meaning the lid overhang might be the perfect medium for growing mold etc. But as long as the plates are kept in a sterile container there should be little problem.

 

[TidalPete]

ok 19th or 26th....either is good for me

[post="75223"][/post]​

Ozbrewer,
I am hopeful that I can make it on the 26th as well if you decide on that date.

:beer:

 

[TidalPete]

Anyways is the yeast swap still going ahead?

[post="76977"][/post]​

yeah, have we decided on a date?

[post="77004"][/post]​

The Yeast Swap date is when? :blink:
As opposed to Ozbrewer's demo which is on the ?-? 05. :blink:
When is the yeast swap date? :huh:
Hope I'm not being rude here?

:beer:

 

[ozbrewer]

ok lets decide on a date?.....how about the 4th of dec to match up with the Xmas case.......all in favor

 

[Ross]

ok lets decide on a date?.....how about the 4th of dec to match up with the Xmas case.......all in favor

[post="77810"][/post]​

yep, suits me...

 

[AndrewQLD]

sounds good to me too.