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How not to sanitize your airlocks

Posted: Sun Feb 04, 2024 1:35 pm
by Lblamboy
Apparently some cheap plastic airlocks melt at/around 212F - :shock: so don’t boil them in water/PBW and assume it will be fine (the lids were fine) (others I would swear I have boiled successfully, so ymmv…it’s possible these failed due to age or heat/cold cycles in storage causing the plastic to change somehow?!)

Re: How not to sanitize your airlocks

Posted: Sun Feb 04, 2024 3:53 pm
by Demy
I would say the problem is temperature.....there are better ways to sanitize plastic :roll:

Re: How not to sanitize your airlocks

Posted: Sun Feb 04, 2024 4:25 pm
by Saltbush Bill
Why on earth bother at all ?, sounds like a habit left over from beer making.

Re: How not to sanitize your airlocks

Posted: Sun Feb 04, 2024 4:46 pm
by Lblamboy
Saltbush Bill wrote: Sun Feb 04, 2024 4:25 pm Why on earth bother at all ?, sounds like a habit left over from beer making.
It was a free bit of goodies from an unknown person who had it stored in relatively unsanitary conditions - I planned on both cleaning and desanitizing with a boil, and also then using starsan!

It certainly was a temperature problem - but I’ve used similar airlocks and had them in very hot water before. I wouldn’t have expected many plastics would melt below 212F though. I was surprised, which is why I posted. Surely I’m not the only one who might have assumed (and you know what they say about assuming) that boiling stuff to sanitize it would be fine.

Re: How not to sanitize your airlocks

Posted: Sun Feb 04, 2024 5:13 pm
by shadylane
Lblamboy wrote: Sun Feb 04, 2024 4:46 pm
It certainly was a temperature problem - but I’ve used similar airlocks and had them in very hot water before. I wouldn’t have expected many plastics would melt below 212F though. I was surprised, which is why I posted.
As you found out, not all plastic is the same.
Thanks for the heads up and entertainment. :lol:

Re: How not to sanitize your airlocks

Posted: Sun Feb 04, 2024 6:13 pm
by Yummyrum
I’d say it was Polystyrene . It has a glass transition stage very close to 100°C even though its melting point is up around . 240°C

The exact transition temp will vary slightly . Hence why you had some that survived previously .

I used to have to make and dispose of petrie dishes . We had to make sure the agar was sufficiently cool before pouring it into the dishes as if it was still boiling it would often warp the dishes . To dispose of I had to put them in a pressure cooker at 15-20psi . Thats around 120°C . They would be completely shrivelled up into lumps .

Re: How not to sanitize your airlocks

Posted: Mon Feb 05, 2024 3:51 am
by Renhoekk
Saltbush Bill wrote: Sun Feb 04, 2024 4:25 pm Why on earth bother at all ?, sounds like a habit left over from beer making.
Same thought I had….one of my favourite things about fermenting for distilling is that I don’t have to sterilise the bejeebus out of everything