Yeast Containers (same As Whitelabs Tubes)

[NRB]

Perhaps they gamma irradiate them?

 

[PostModern]

Perhaps they gamma irradiate them?

I wouldn't be surprised. Seeing as no chemical that wouldn't destroy the PET kills 100% of pathogens, and heat treatment is out of the question...

 

[SpillsMostOfIt]

Apologies if this is a stupid question, but assuming the plastic is microwave-safe, can/could you use a microwave oven to sterilise them? Are bacteria, etc microwave-resistant?

 

[NRB]

In order to render an object sterile in a microwave it will need a lot of heat. Bacterial endospores are very hard to destroy which is why significant heat and pressure are required for a 'reasonable' amount of time (dependent on temperature and pressure... increase one, decrease the other).

For instance one of my Class B autoclaves at work runs a 5 minute sterilisation cyle - 134C at 2.1bar pressure.

A pressure cooker will achieve 121C at 15psi; approximately 30 minutes of these conditions are required to render a non-canulated object sterile.

 

[SpillsMostOfIt]

In order to render an object sterile in a microwave it will need a lot of heat. Bacterial endospores are very hard to destroy which is why significant heat and pressure are required for a 'reasonable' amount of time (dependent on temperature and pressure... increase one, decrease the other).

For instance one of my Class B autoclaves at work runs a 5 minute sterilisation cyle - 134C at 2.1bar pressure.

A pressure cooker will achieve 121C at 15psi; approximately 30 minutes of these conditions are required to render a non-canulated object sterile.

That makes me feel a bit intimidated at the prospect of yeast farming. How do people without all the cool gear do it? Is there more luck involved? I am yet to encounter an infection in my brewing that I could identify and I understand that it is more crucial when it comes to yeast, but...

 

[PostModern]

For instance one of my Class B autoclaves at work runs a 5 minute sterilisation cyle - 134C at 2.1bar pressure.

A pressure cooker will achieve 121C at 15psi; approximately 30 minutes of these conditions are required to render a non-canulated object sterile.

Either of which would render these tubes unusable. So how do Whitelabs sterilise??? Googling has so far brought me nothing but Chris White's BYO article recommending either bleach or oven baking to sanitise an Erlenmeyer flask.

 

[Yeasty]

Because that would be sanitising, not sterilising...
How does Whitelabs sterilise/sanitise before packing? Doc, you went to their plant didn't you?

ahh...me forgets

I bet everyone is stressing too much and Whitelabs just dunk em in bleach for a while

 

[Darren]

Because when dealing with such small quantities of yeast for storage and stepping up, you need to minimise if not prevent contamination completely. Bacteria will multiply 10 times faster than yeast. Rememeber that they multiply by binary fission meaning an exponential scale.

Yeast farming requires the use of a sterile field.

That is correct. Also you would be best advised to sterilise the "yeast water" inside the tube. That is add the water to the tube and boil the crap out of them. This will minimise the risk of contamination. The is no point in saving $15 for a smack-pack if you throw out three $30 brews because your yeast stocks are poor quality..

Edit: Upon reading the rest of the thread, Whitelabs probably do Gamma irradiate their tubes. They also package their yeast in "cleanrooms". I spoke for quite some time to Chris White when he came to Adelaide. I can assure you guys that their quality control is far and above ANY homebrewer I have met. Cross contamination of strains is the biggest problem with yeast farming. All of their strains are plated out on agar to inspect colony morphology to ensure it looks as it should (shape, size, colour). All transfers are carried out under sterile air.

So, just because you are using the same tube, does not mean that you are doing as Whitelabs.

cheers

Darren

 

[TidalPete]

Also you would be best advised to sterilise the "yeast water" inside the tube. That is add the water to the tube and boil the crap out of them. This will minimise the risk of contamination. The is no point in saving $15 for a smack-pack if you throw out three $30 brews because your yeast stocks are poor quality..
Darren

As I don't have a pressure cooker, I add sterilised water to my tubes before boiling them for 30 minutes or so. When cooled down I empty tube "A", add my yeast, top up with sterilised water from tube "B", seal "A" with cap then empty tube B etc,etc.

Not saying that this is ideal but I have done this for over 18 months without an infection. Maybe I'm just lucky?

:beer:

 

[SpillsMostOfIt]

Not saying that this is ideal but I have done this for over 18 months without an infection. Maybe I'm just lucky?

:beer:

Maybe you're just enjoying the taste of your infections?

 

[Darren]

As I don't have a pressure cooker, I add sterilised water to my tubes before boiling them for 30 minutes or so. When cooled down I empty tube "A", add my yeast, top up with sterilised water from tube "B", seal "A" with cap then empty tube B etc,etc.

Not saying that this is ideal but I have done this for over 18 months without an infection. Maybe I'm just lucky?

:beer:

TP,
Looks ok to me. You are not using the PET blanks though are you?
If so, how well did they survive the boil with water in them?

cheers

Darren

 

[TidalPete]

TP,
Looks ok to me. You are not using the PET blanks though are you?
If so, how well did they survive the boil with water in them?

cheers

Darren

No Darren I'm using the tubes from the Ausdaub bulk buy quite a while back. See post 30 for the link.

:beer:

 

[drsmurto]

I use tubes made by Sarstedt Australia at work they are graduated to 50mL in 5mL steps, they are made from HDPE we heat these past 120C as part of our process. I would guess they are 80mm long and 25mm across. And they have a point bottom.

We buy them science supplies australiaI don't know the price.

Got something similar here at work too, somehow a few seem to have emigrated to my place. All get an acid wash after use.

They are called 50mL centrifuge tubes, are made from PP and can be autoclaved. The price work has been quoted is $64+GST for a box of 500. Catalogue # LBSCT5203. Biolab are the people to call (1300 735 297).

Cheers
DrSmurto

 

[Doc]

How does Whitelabs sterilise/sanitise before packing? Doc, you went to their plant didn't you?

Yes, I've been to White Labs in San Diego where their lab is, and got to check it all out.
They weren't packaging whilst I was there, just propogating, so I didn't see what process they did to the vials before packaging (if any).

Beers,
Doc

 

[crozdog]

What a bummer, I gave 100 empty White Labs vials to Crozdog. I knew I should have held onto them.
Gerard

Gerard, just thought you'd like to know they are doing well @ my place. Guess I was in the right place @ the right time. Thanks :beer:

FWIW, My cleaning technique (I won't call it sterilisation ;-) ) for yeast culturing is as follows:
- a soak in sodium percarbonate
- a clean water rinse
- iodophor rinse
- then I use a 40+% ethanol solution for a final rinse before use.

I do this for both the tubes & the caps/lids.

 

[dgcooke]

I am good for 50 or 100 but I need caps so let us know about the caps as soon as you know the cost.

Damien

Just got an email back

we can get 5800 units for $130 + GST + transport costs to the door so looks like they could be quite cheap.
still waiting on a email about the caps.

these tubes are what softdrink bottles are formed from

Franko