Yeast..

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Wyeasts pack is the starter mechanism, for a 22l batch at medium gravity there is little need to make a starter. Smack, wait for the pack to swell and away you go.

All yeasts are a tough things, I have had 4-5 year old packs come alive once smacked, took about 7 days but they still worked fine.

For other pack types, if in doubt then go for a started I guess, but as Wyeast gives you the advantage of easily knowing if your goose is cooked, i rarely stray from the product...

Scotty

 

[Lindsay Dive]

Wyeasts pack is the starter mechanism, for a 22l batch at medium gravity there is little need to make a starter. Smack, wait for the pack to swell and away you go.

All yeasts are a tough things, I have had 4-5 year old packs come alive once smacked, took about 7 days but they still worked fine.

For other pack types, if in doubt then go for a started I guess, but as Wyeast gives you the advantage of easily knowing if your goose is cooked, i rarely stray from the product...

Scotty

Hi Scotty,

Whitelabs have already made a starter for us to use and then simply put the little yeasties into hibernation until such time as we wish to use them.
They also state that their vial is good for 5 US gallons which is a little under 19 litres.

As you know, I'm a plater and streak all my yeasts onto plates. In the past I have discovered infections on both Whitelabs vials and also Wyeast smackpacks. This is a rarity, but sadly, a fact.

I strongly recommend folks to make a starter, smell the starter and also taste a little of the starter before pitching it into your prized wort.

I have attached a photograph of a badly infected yeast that was streaked directly from a yeast suppliers container using a red hot platinum loop. I cleaned this yeast up by streaking a fresh plate from a colony from this plate that was not infected.


Regards,
Lindsay.

 

[justsomeguy]

Hi Scotty,

Whitelabs have already made a starter for us to use and then simply put the little yeasties into hibernation until such time as we wish to use them.
They also state that their vial is good for 5 US gallons which is a little under 19 litres.

As you know, I'm a plater and streak all my yeasts onto plates. In the past I have discovered infections on both Whitelabs vials and also Wyeast smackpacks. This is a rarity, but sadly, a fact.

I strongly recommend folks to make a starter, smell the starter and also taste a little of the starter before pitching it into your prized wort.

I have attached a photograph of a badly infected yeast that was streaked directly from a yeast suppliers container using a red hot platinum loop. I cleaned this yeast up by streaking a fresh plate from a colony from this plate that was not infected.
View attachment 11355

Regards,
Lindsay.

Hi Lindsay,

Just a quick question. How could you tell the good colonies from that bad on that plate ?

gary

 

[Adamt]

Good colonies are the round solid white dots, bad ones are the ones that look like they exploded.

 

[liberty_nz]

Hi Lindsay,
Where did you get your yeast culturing gear? I keen to start yeast farming but can't find a medical supplies type outfit that will sell me the gear here in New Zealand. Do you know if there is anyone in Oz who will sell via the internet?

 

[apd]

Wyeasts pack is the starter mechanism, for a 22l batch at medium gravity there is little need to make a starter. Smack, wait for the pack to swell and away you go.

Scotty, I've been working under the assumption that the Wyeast pack is a viability test rather than a starter (see Mr Malty's pitching rates page).

From that page:

The little bit of nutrient in a Wyeast smack pack does not take the place of a starter. It is there to jump start the culture's metabolism and to act as a built-in viability test.

and

...a 1.048 wort pitching into 5.25 gallons you need about 180 billion cells

and

A Wyeast Activator pack (the really big ones) and the pitchable tubes have an average of 100 billion cells of 100% viable yeast. The smaller packs are around 15-18 billion cells.

So according to Mr Malty, you'd need 2 big Wyeast activator packs to get the correct cell count for the average ~23L batch.

Of course, as with everything in brewing, there's the 'proper' way of doing something and then there are the 10 other ways that usually give you just as good a result.

 

[Lindsay Dive]

Hi Lindsay,
Where did you get your yeast culturing gear? I keen to start yeast farming but can't find a medical supplies type outfit that will sell me the gear here in New Zealand. Do you know if there is anyone in Oz who will sell via the internet?

Liberty,
You will have to do some seaching via google in New Zealand and find out where you can get some Petri Dishes. I use the plastic 'throwaways' they are sterilised and are the 90mm type with lid. I get mine from
http://www.livingstone.com.au/
You will also need some gear to make the medium for the yeast to grow on. Some folks use agar agar and some dry malt extract mixed up to about a 1.040 S.G. Personally, I use a dehydrated culture medium named Sabouraud Agar Modified. I buy this from Bacto Laboratries in Sydney, http://www.bacto.com.au/
I also use two antibiotics (I think), Gentamicin and Chloramphenicol. These prevent a lot of unwanted nasties contaminating your plates, however, do not affect the growth of yeast colonies.

To make twenty plates, (each plate contains 20 grams of prepared medium) you need 19 grams of the Sabouraud Agar Modified, 400 mls of sterile water, 1.35 ml of Chloramphenicol ((4800 mg/l) (you can get this from a friendly Chemist or a combination of the friendly Doctor and Chemist), and .16 ml (please note, point 16) of Gentamicin (80 mg/2 ml). Gentamicin is in the products that are used for making eye drops when suffering from Conjunctivitis.

You will also need some disposable sterile plastic inoculation loops.

I buy 30ml disposable syringes and use these without the needle to squirt the 20 mls of liquid medium into the Petri Dishes.

Good Luck,
Lindsay.

 

[sstacey]

Lindsay,
I am thinking about storing my yeasts on plates too. I have a couple of questions:
How long does it take to step up a small colony/streak of yeast from a plate into a reasonable sized starter? What procedure do you use?

Secondly, do you plate up in a laminar flow cabinet or what precautions do you take to prevent infection on the plates?

Cheers!

 

[Lindsay Dive]

Lindsay,
I am thinking about storing my yeasts on plates too. I have a couple of questions:
How long does it take to step up a small colony/streak of yeast from a plate into a reasonable sized starter? What procedure do you use?

Secondly, do you plate up in a laminar flow cabinet or what precautions do you take to prevent infection on the plates?

Cheers!

I'll tell you what I do and keep it in mind it may not be the best solution. There could be some knockers of my procedure but I've been doing it for many years now and I'm not about to change.
Once I have the prepared SAB plates, I streak over an alcohol flame with a platinum inoculation loop. If I want to use that particular yeast, I streak two plates with the same yeast and clearly mark the plates with a textra. I then place the plates somewhere warm; I use the top of the Foxtell box thingy.
Once the colonies grow to the size you like, about 3 - 4 days, store one of the plates in the fridge after sealing it with Parafilm,
http://www.livingstone.com.au/item_info_po...amp;item_id=170
I then prepare a two litre starter, I know that a lot of folks step up from 500 ml to 1 litre and then 2 litres; however, I find that the fresh yeast colonies taken from one full plate will fire up two litres in a matter of hours.
I then pitch that yeast at or near to high krausen.
I also use a stir plate with the two litre starter.
I do not use any other procedure to prevent infections other than washing down my work area (kitchen bench top) with methylated spirits, wear disposable latex gloves and I wear a small face mask. Right at the time of streaking a plate, I do not breathe.
Do not plate where there is a fruit basket. That blue mould that you see appears on old oranges is an absolute ******* around SAB plates.
Do not plate anywhere near where you crush your grain.

Good luck,
Lindsay.

 

[sstacey]

Thanks Lindsay,
I was thinking about building a small laminar flow cabinet. But maybe I should have a go using your mehtod first and see how it goes.
Much appreciated

 

[sam]

I've read that little booklet that was put out by Whitelabs a while ago, by Chris White, on yeast culturing. He recommended using a small alcohol lamp in the area your working to prevent airbourne contamination. Sounds like a good, cheap alternative.

But I've never done any culturing, or used an alcohol lamp, so I don't really know.

sam

 

[xtrabyte]

One company I worked for built a cabinet similar to a laminar flow cabinet and put in some lights that gave off UV light. (Laminar flow cabinets are very expensive) The lamps stayed on all the time, unless the microbiologist was using it. This kept the air and plating/working area almost completely sterile. It was very cheap to put together. He did not turn them off one and ended up with the condition welders get when they dont wear protective eye gear, arc eyes!!

As far as media goes you could try 3M petri film, not cheap but easy to use. A pressure cooker could be used in place of a Micro Lab Retort and you need not use antibiotics in your made up media. You can buy indicator tape to put on anything to want to sterilize. Once the tape reaches 121C for 15 minutes black lines show up to indicate it is sterile.

 

[berazafi]

Why try and reinvent the wheel, simple easy procedure

http://oz.craftbrewer.org/Library/Methods/...YeastHand.shtml