Sterilising Plastic Test Tube Lids

Australia & New Zealand Homebrewing Forum

Help Support Australia & New Zealand Homebrewing Forum:

_HOME_BREW_WALLACE_

Professional Drunken Yahoo!
Joined
30/6/09
Messages
1,365
Reaction score
68
I have recently acquired 50 x 30ml glass test tubes with plastic lids which i will use to split liquid yeast packs.

My issue is (after a bit of a read on this site and Google sterilising the lids) without heat (because they are pretty flimsy lids) the only way to sterilise these lids would be to use isopropyl alcohol.

Am I right? Please correct me if i am wrong. I know there is a difference between sanitising and sterilising. If the lids only have to be sanitised for yeast storage I will just use starsan.

What do you guys do if you don't mind me asking?
 

RdeVjun

Well-Known Member
Joined
19/1/09
Messages
2,340
Reaction score
172
Yep, that's what I'd do although I use ethanol, and only after a soak in perc to ensure they're cleansed. Try one in heat first perhaps, they might stand it? (Edit: Ditto with any solvent- they could melt too!)
I've also used foil to close glass test tubes, not as smart as a lid but effective nevertheless as it can be heat- treated, a few layers provides some integrity (just one layer won't) and then use a pipecleaner or rubber band to hold it in place after filling.
 

_HOME_BREW_WALLACE_

Professional Drunken Yahoo!
Joined
30/6/09
Messages
1,365
Reaction score
68
Yep, that's what I'd do although I use ethanol, and only after a soak in perc to ensure they're cleansed. Try one in heat first perhaps, they might stand it?
I've also used foil to close glass test tubes, not as smart as a lid but effective nevertheless as it can be heat- treated, a few layers provides some integrity (just one layer won't) and then use a pipecleaner or rubber band to hold it in place after filling.
Ethanol...... Where do you get that? Just the chemist? Is it any better than Isocol? (the stuff you get from woolies)
 

punkin

Rarely Serious
Joined
25/6/11
Messages
2,116
Reaction score
345
If the lids are PP (poly propelene), and they should be, they'll withstand heat. Wrap them in foil and sterilise @ 15psi for 15 mins in a pressure cooker.
 

_HOME_BREW_WALLACE_

Professional Drunken Yahoo!
Joined
30/6/09
Messages
1,365
Reaction score
68
If the lids are PP (poly propelene), and they should be, they'll withstand heat. Wrap them in foil and sterilise @ 15psi for 15 mins in a pressure cooker.

No pressure cooker :(

The lids are pretty soft. I can fold them in half with my thumb and index finger.
 

RdeVjun

Well-Known Member
Joined
19/1/09
Messages
2,340
Reaction score
172
Lab supply for ethanol, but they won't sell it to just anyone I'm afraid, we use it primarily to preserve aquatic ecology specimens. I've heard supermarket metho is quite OK as a substitute though, but again I'd just test one first to be sure.
 

punkin

Rarely Serious
Joined
25/6/11
Messages
2,116
Reaction score
345
If the lids have a symbol, the PP symbol is 5 in a triangle.

You can use a microwave and heat them for 1-2 mins in boiling water, but not as effective. Some people have been known to make their own ethanol believe it or not ;)

Metho will work too. it only has to be 70-80%abv.
 

pk.sax

RIP bum
Joined
19/8/10
Messages
4,362
Reaction score
415
Or spirytus from dan's. Somewhere close to the vodkas. It's 95% and not very cheap. But then again, 95%...
 

TidalPete

BREWING BY THE BEACH
Joined
2/8/04
Messages
5,182
Reaction score
480
Location
Sunshine Coast, Queensland
Agree with punkin here. Did the mob who sold you the vials advertise them as autoclavable?
BPC (before pressure cooker :D ) I boiled my autoclavable tubes & caps in a covered saucepan for 30 minutes. Not foolproof by any stretch but 90% of the time it worked. Recommend getting a pressure cooker ASAP. Aldi have them on special from time to time.
Tried those Masterfood spice bottles & lids in the pressure cooker once but sadly the lids weren't up to the job.

TP
 

_HOME_BREW_WALLACE_

Professional Drunken Yahoo!
Joined
30/6/09
Messages
1,365
Reaction score
68
Agree with punkin here. Did the mob who sold you the vials advertise them as autoclavable?
BPC (before pressure cooker :D ) I boiled my autoclavable tubes & caps in a covered saucepan for 30 minutes. Not foolproof by any stretch but 90% of the time it worked. Recommend getting a pressure cooker ASAP. Aldi have them on special from time to time.
Tried those Masterfood spice bottles & lids in the pressure cooker once but sadly the lids weren't up to the job.

TP

I just dropped them an e-mail and so i'll have to wait a while for a reply.
About the pressure cooker, I don't have one but i'll ask mum if she will mind if i use hers for a couple of hours........ :D

I have 50 of the Fcukers........ What do I have to lose?
 

TidalPete

BREWING BY THE BEACH
Joined
2/8/04
Messages
5,182
Reaction score
480
Location
Sunshine Coast, Queensland
I have 50 of the Fcukers........ What do I have to lose?
WALLACE,

Perhaps sterilise those Masterfood jars & lids by boiling the crappers out of them for 30 minutes & if the lids fail then cover the jars with sanitised alfoil sealed with a tightly-bound rubber band?
You can do the same when you nick your mum's pressure cooker :p. Too easy!

TP
 

punkin

Rarely Serious
Joined
25/6/11
Messages
2,116
Reaction score
345
Guys, sanitising won't do in these situations.

I do a bit of mycology (mushrooms) work and have an elaborate setup. Sterile ain't sanitised....

got this sucker behind my comp in the office...

flowhood7.jpg
 

Lobsta

Well-Known Member
Joined
6/1/08
Messages
418
Reaction score
0
If using ethanol, use 70%, not higher. 70% is the optimal strength for sterilization. There is an explanation, but it involves big words, so google it. That is why isocol and those alcohol based hand sterilizers are all 70%. So metho is out as it is 95ish, plus I personally wouldn't put methanol anywhere near anything that goes into a brew. Not sure if I would do the same with isopropyl alcohol either. 70% ethanol isn't too easily available to mere mortals, but if you are friendly with your local chemist, they may hook you up. We can order it in 2L bottles no stress.

Lobby
 

WitWonder

Well-Known Member
Joined
31/12/07
Messages
442
Reaction score
25
I've also used foil to close glass test tubes, not as smart as a lid but effective nevertheless as it can be heat- treated, a few layers provides some integrity (just one layer won't) and then use a pipecleaner or rubber band to hold it in place after filling.
Dust/airborne particles can penetrate a layer of aluminium foil? Wow... :rolleyes:

I do a bit of mycology (mushrooms) work and have an elaborate setup. Sterile ain't sanitised....
True, but FWIW I've never had an issue with yeast storage and all I've ever done is sanitise my test tubes with starsan prior to use.
 

RdeVjun

Well-Known Member
Joined
19/1/09
Messages
2,340
Reaction score
172
Dust/airborne particles can penetrate a layer of aluminium foil? Wow... :rolleyes:
Actually buddy, you know what- I never said that. But if you're thinking that just one single layer of foil is going to protect a tube perfectly throughout the rigours of the various handling and storage steps involved without tearing, then by all means go for it- I wish you the best of luck ! :icon_cheers:
I used the word integrity with some forethought, did you do the same for penetrate? :rolleyes:
 

TidalPete

BREWING BY THE BEACH
Joined
2/8/04
Messages
5,182
Reaction score
480
Location
Sunshine Coast, Queensland
I've also used foil to close glass test tubes, not as smart as a lid but effective nevertheless as it can be heat- treated, a few layers provides some integrity (just one layer won't) and then use a pipecleaner or rubber band to hold it in place after filling.
Must have missed this after too many Belgians & stand corrected Ralph. Your knowledge of these things is so much better than mine. :icon_cheers:

WALLACE --- Three layers of alfoil over your tubes\jars mate (I'll be doing this when needed from now on) but don't forget to really tighten that rubber band. :D


TP
 

RdeVjun

Well-Known Member
Joined
19/1/09
Messages
2,340
Reaction score
172
Multiple layers of foil to close tubes is just one alternative TP, if you have caps that are autoclavable then use them! :icon_cheers:

I should've mentioned that roughly 1/3 water and 2/3 ethanol is a preferred mix, so Lobsta is quite right. I wouldn't use it on production wort surfaces however IMO it is quite OK on caps, smack pack exterior, scissors/ knife, so just about anything to do with the starter prep that isn't/ can't be steamed, however I do steam and fire the loop. 100% may not be as effective as 70% for sanitation, however it does dry a bit quicker and does a decent job on cleaned surfaces.
 

Latest posts

Top