Sanitising Yeast Vials?

[bignath]

Hi all, want to start my adventures into collecting, storing, reusing, splitting yeasts.

Those little 30ml plastic vials...........how do you sanitise them?

I have done a quick experiment with the microwave and kettle to see how they handle boiling liquid and so far so good. I filled two of them to the brim, put one in the microwave on high for 2 minutes, the other one i filled to the brim with boiling water straight from the kettle. They seem to handle boiling temps without any noticeable change. Is boiling them the best way? Or do you guys have any other tips....

 

[stux]

Microwave Baby bottle sanitizers?

Pressure cookers?

Mine come sterile, I use them that way

 

[Krmak]

Hi all, want to start my adventures into collecting, storing, reusing, splitting yeasts.

Those little 30ml plastic vials...........how do you sanitise them?

I have done a quick experiment with the microwave and kettle to see how they handle boiling liquid and so far so good. I filled two of them to the brim, put one in the microwave on high for 2 minutes, the other one i filled to the brim with boiling water straight from the kettle. They seem to handle boiling temps without any noticeable change. Is boiling them the best way? Or do you guys have any other tips....

you can always put them in a glass jar and use a pressure cooker if you're not sure that they can handle that much heat...

 

[bignath]

Was gonna try putting them all in a saucepan and boiling some water.

I know they come sterile when new, but mine came from a very kind AHB member and was thinking of sterilising this batch, and then reusing them later.

Does this sound like a plan?

 

[RdeVjun]

I think they're Polypropylene, so good to around 130C and I reuse them. Making slants about half full of agar agar wort, I steam them in my big stockpot for an hour with no bother at all, just in the rack with the lid on tight. Then set them in the rack on the right angle for the slant surface (>45deg). When they're cool and you're ready to inoculate, open them up and shake the excess condensation out gently (not too vigorous or the agar agar block flies out! ), should be happy days. :icon_cheers:

 

[stuchambers]

If they are a good quality brand they should handle high temps no problem, at work we sterile them in an autoclave at 121 degrees.

 

[bignath]

Thanks for the advice guys...

And also a huge thanks to RdeVjun for setting me up with all the tubes, rack and some yeast slants! Really appreciate it mate!

They are in the stockpot right now 'cooking'.

 

[Wolfy]

If you're using them for yeast cultures (or other small amounts of yeast or long-term storage of yeast) you should be trying to sterilize them not just sanitize them.
A pressure cooker (cheap autoclave) is a very good option (if you have one), however if you don't then repeated boiling (15mins at a time over 3 days without opening the boiling container, see Tyndallization) is what I'd suggest.

 

[bignath]

If you're using them for yeast cultures (or other small amounts of yeast or long-term storage of yeast) you should be trying to sterilize them not just sanitize them.
A pressure cooker (cheap autoclave) is a very good option (if you have one), however if you don't then repeated boiling (15mins at a time over 3 days without opening the boiling container, see Tyndallization) is what I'd suggest.

Thanks wolfy (twice )

Im gonna start simple....i have a wyeast 1056, which im gonna split four ways into these vials, and then use them to build up a starter for a few batches.

Not up to the level of your yeast knowledge, or RdeVjun's agar slants yet. Just want to dip my feet into making my yeast go further.

Might look into pressure cookers.

Cheers,

Nath

 

[Tony]

While im boiling my starter in a pot, i put some water in my erdinger flask, put a tin foil cap over it (that will ramain when the yeast goes in) and put the vials and caps in the water..... and bring it to the boil.

Steralise the flask and the vials all in one!

I have even started putting the starter wort in the flask while boiling hot and cooling it in the flask in the sink full of water (no chill style) and pitch the yeast when cooled. Takes the same amount of time as in the pot but less lightly to splash something in there or have one of the kids put a finger in it etc

cheers

 

[WitWonder]

I guess I have been pretty slack then - I just sanitise mine before use; no problems (yet). They are the plastic type (polypropylene?) - maybe I should boil and see if they distort.

 

[pyrosx]

you can always put them in a glass jar and use a pressure cooker if you're not sure that they can handle that much heat...

This sounds like an explosion waiting to happen to me

 

[Krmak]

This sounds like an explosion waiting to happen to me

why explosion waiting to happen?
if the plastic is not PE and melts in the pressure cooker, it melts in the glass container, let's say a canning jar so you don't wreck your pressure cooker - they are not so cheap . The only thing that would explode would be if the vials with liquid inside would have sealed caps instead of loose?

:icon_cheers:

 

[RdeVjun]

No sweat Nath! Apologies though, I was thinking of slants instead of splitting.
I'll never be foolish enough to question Wolfy on yeast matters, or any beery issue for that matter, however what I'd suggest with slants is that by preparing them well in advance they can undergo a proofing period after heat treatment in which you can easily tell whether it was adequate. Leave them sit at room temps for few weeks after they've been through the steamer, any that weren't sanitary will be obvious as they will have a hideous growth, if just one is dodgy then toss the whole batch and start again. This happens well before you inoculate, so is to your advantage to be organised and you can then be reasonably confident you're working with reliable media. Of course, apart from sterilizing in an autoclave, the Tyndallization method would be fine, this is just an alternative method with a feedback loop, probably falls somewhere in between there and sanitising, however FWIW it seems to be working OK for me so far.
As per Tony, I use the big pot to heat treat all sorts of things in preparation for opening a fresh pack of liquid yeast, here there's usually there's starters in Schott bottles and flasks, a few small stainless cups in a tray and a couple of stainless skewers, all stacked in there. Never be scabby with the heat units is my advice, always be quite generous and take your time- boiling of starter wort in the flasks or bottles and break forming is a good sign, wait a good while longer after that before shutting off the heat!

 

[argon]

The little jars I use for splits come sterilised. But after the first use I use the baby "steriliser". Give it a go 4 mins at a time for a few turns. The heat, and hence steam, it produces is damn hot and will more than likely pasteurise/sterilise anything within. I figure the vessels are at, or above, boiling point for over 30 mins durning a few cycles.

 

[lickapop]

quote of the day " I've just taken a shit can somebody wipe my arse" big nath -stir plate thread
I find it quite comical that you would start a thread just as dumb.
No offence but you have some serious basic googling to do as well.
But fwiw 15psi pressure cooker, 15min.... Done. I just saved you a whole heap of **** around and disappointment

 

[bignath]

quote of the day " I've just taken a shit can somebody wipe my arse" big nath -stir plate thread
I find it quite comical that you would start a thread just as dumb.
No offence but you have some serious basic googling to do as well.
But fwiw 15psi pressure cooker, 15min.... Done. I just saved you a whole heap of **** around and disappointment

**** off idiot....

The number of intelligent replies that my question has received is proof that its not a stupid question to ask...

I have recently been given (by another member RdeVjun) a sizeable quantity of vials, a rack, and some WYEAST PRIVATE COLLECTION range yeasts. Very generous of him.

I know how to keep my stuff clean and sanitary. I wanted to know if those plastic vials could withstand boiling for an extended period of time as a suitable method of sanitising or sterilising - or not. The last thing i wanted to do was destroy them by subjecting them to a method they were not designed for, and therefore waste his efforts to get me started.

I didnt come down with the last shower, sunshine.

On the flipside, the fact that most of the other posts on that thread re:stirplates has received similar responses to mine given, indicates im not alone here.

Hmmm, stirplate. One switch and one speed potentiometer. If its that hard to work out, then actually using one is the least of the problems.

 

[pyrosx]

Look up the "sterilising" power of 100 degree steam - in fact, ill do it for you: here- it doesnt kill prions or bacterial spores.

Wolfy was quite clear - and the wiki he linked explained it fully - by boiling once a day for 3 days, you will probably kill 99% of the stuff that survives 100 degree steam. But it still, technically, isn't "sterilization" - by todays standards, anyway.

I'd go so far as to say that the microwave baby "sterilizers" should actually be called "sanitizers" - they'll kill most stuff that's harmful if ingested in the next day or so - but would you trust that baby formula kept in a microwaved bottle for 6 months has had absolutely nothing nasty grown in it over that time? There's a possibility that microwaves will super-heat the water, but that doesn't tend to get more than 105 degrees - and that still isn't in the 120-130 range for proper sterilization.

I'm not at the point where i've put any of this theory into practice - and there are already people in this thread saying that they've "never had a problem".... but i'm dealing in and reporting scientific

 

[bignath]

Look up the "sterilising" power of 100 degree steam - in fact, ill do it for you: here- it doesnt kill prions or bacterial spores.

Wolfy was quite clear - and the wiki he linked explained it fully - by boiling once a day for 3 days, you will probably kill 99% of the stuff that survives 100 degree steam. But it still, technically, isn't "sterilization" - by todays standards, anyway.

I'd go so far as to say that the microwave baby "sterilizers" should actually be called "sanitizers" - they'll kill most stuff that's harmful if ingested in the next day or so - but would you trust that baby formula kept in a microwaved bottle for 6 months has had absolutely nothing nasty grown in it over that time? There's a possibility that microwaves will super-heat the water, but that doesn't tend to get more than 105 degrees - and that still isn't in the 120-130 range for proper sterilization.

I'm not at the point where i've put any of this theory into practice - and there are already people in this thread saying that they've "never had a problem".... but i'm dealing in and reporting scientific

Thanks mate. I suspected most of that would be the case. I dont have access to a pressure cooker, or a baby sterilising kit (anymore). Had not many other options other than a stockpot. Have boiled the vials for over an hour in my best attempt at sanitising them and have filled three cooled vials with 1056 to use another day. Will build up a 2lt starter with one for the next ferment, and will have a good 'ol sniff and taste before i pitch.

Cheers for your help.

 

[Silo Ted]

If they are a good quality brand

Isnt Nath talking abut the WLP vials? I was of the impression that they are soft drink bottle blanks, intended to be blown into shape by hot air. Therefore no "good brand" as such.

Let us know Nath. I would be inclined to wrap one in foil & PC it.