Autoclaving...

[James L]

Guys,

I have had a recent spout of recurring infections with my brews (could be brett), and i thought istead of throwing out the fermenters, i would take them to work and autoclave them. the only question is, are the standard (i think its polyethylene) fermenters capable of withstanding 121C without permanent damage? Has anyone attempted this?

I was also thinking about autoclaving my plate chiller (30 plate), i dont think the metal would have any trouble with the temps, but i'm not sure about the welds. Has anyone autoclaved one of these?

Chances are i'll give it a go, but i thought i'd ask the questions...

James

 

[fraser_john]

I cannot respond about the fermenters, but I use a pressurised steam generator to sanitise my counter flow chiller and its only brazed together, never had any issues with the welds. I have not measured how hot it gets, but I know from accidentally bumping it one time with my forearm during the process that it creates a NASTY burn, so its gotta be getting hot!

 

[paulwin]

hi james im not to sure about the fermenters but the plate chiller will be fine
i clean my plate chiller will boiling water and napisan which i pump through for about 20 min
are you the james i sat next to at the west coast brewers meeting on monday night
cheers paul

 

[James L]

Yeh, typically autoclaves work at 121C, at 100kpa give or take.

If anything, i'll do the taps, and if they shit themselves, i might have to find alternative sterilising methods for the fermenters.

 

[mesa]

Hi James,
I'm pretty sure they are HDPE. From what I remember HDPE is "rated" (i.e. completly stable) to less than 100C. Having said that I think plenty of people have boiled in them with just some softening. Wikipedia suggests the melting point for HDPE will be in the range 120-130 (and that it depends greatly on density)

BTW I don't think the taps will necessarily be made of the same stuff as the fermenters. I've got some black ones and some clear/white ones. I wouldn't be supprised to learn the black ones at least were polyprop (polyprop is supposed to have low friction properties which makes it good for the turn barrel of the tap) IIRC polyprop has a higher temp rating to HDPE so I wouldn't take a test of the taps as conclusive. Also the taps have the o ring which is not the same material (I've got no idea what that is)

I wonder, does brett die at 100C? If you want to borrow one of my heat sticks you could just boil the fermenters (wouldn't really get the lid though)

If your going to stick the fermenter in there, please protect the autoclave from melted plastic

 

[yardy]

wouldn't soaking in a few different sanitisers do the trick ?

ie, soak in bleach, boiling water, starsan and then a hit with iodophor ?

suppose by the time you buy all that you may as well get a new fermenter...

cheers

 

[sumo]

Check the bottom of the fermenter for the compound stamp (HDPE etc), however I found this from one of my container suppliers in NZ, in short I think you would kill it!

High Density Polyethylene

High Density Polyethylene (HDPE) is a rugged material which is easy to mould, has a high resistance to impact and is not affected by most chemicals. Principally used in injection and blow moulding it may also be vacuum formed or extruded.
Working Temperature Range: -35C to +65C

Source: Stowers

 

[reviled]

Check the bottom of the fermenter for the compound stamp (HDPE etc), however I found this from one of my container suppliers in NZ, in short I think you would kill it!

High Density Polyethylene

High Density Polyethylene (HDPE) is a rugged material which is easy to mould, has a high resistance to impact and is not affected by most chemicals. Principally used in injection and blow moulding it may also be vacuum formed or extruded.
Working Temperature Range: -35C to +65C

Source: Stowers

Maybe I should stop using my empty fermenters as a bucket for BIAB :unsure:

What would be the adverse effect of dumping a bag and 78*c liquid in it? Just slightly warped? Unpleasent tastes in next ferment? :blink:

 

[James L]

Yeh PaulBB that was me...

As for the taps, the are made of the same material. But after reading the wikipedia article of HDPE, it is not suitable for autoclaving.

Having said that... it can withstand 120C for short periods of time, so i might chuck it in for about 5-10 minutes instead of the usual 20-30 that i used for other things... As far as i know, other guys in the lab sterilise their 10L water cubes that they used for field water samples with the autoclave and they are made of HDPE...

Also having said that... sodium metabisulfite can kill Brett... so i could try that before anything else...

 

[randyrob]

Hey James,


sorry to hear about your fermentation drama's,

i'm not to sure if it would be brett as i thought this really takes a bit of time to really start adding some funky flavours to your brew.

can you describe the off flavours?

what is your cleaning / sanitation regime for your chiller?

btw i been streaking like a mad man!

Rob.

 

[goatherder]

I'm a bit late to the thread but this link talks about the autaclavability of plastics:

http://www.proscitech.com.au/cataloguex/plastics.asp

hope it helps.

 

[James L]

Rob,

The flavours are quite strange...

Funky smell, and bitter/sour taste. very cloudy. very undrinkable...

I give the fermenter a good soak with percarbs after its been used, and before i put wort into it, i give it a good rinse, and then chuck 5L or so of iodophor and shake it. I give it a good shake every 5 minutes for about half an hour, then pour out and let sit, covered, till its needed. I boil the tap in water for about 15 minutes.

for the chiller, i run iodophor through it for about 20 minutes using a pump.

There may be occasions when i dont give the ferementer the time it needs to be sanitised (but i thought you only needed 10 minutes for iodophor), and maybe that is now coming back to bite me.

 

[randyrob]

Hey James,

soz i missed this before.


yes what your are describing does sound like an infection, so thats a good start.

your cleaning/sanitizing regime sounds ok but just remember (you probably know this better than me!) that you can only sanitize
things that are clean in the first place and when i use my chilller i do a cleaning cycle, then a rinse with hot water before i use
a no rinse sanitizer.

I would really recommend getting back to basics until you can successfully brew a batch without that god awful taste in it.
things like using a fresh pack of dried yeast and stripping your kettle down to it's jocks including the ball valve, if you
don't have a 3 piece ss one get one they are invaluable!

also getting a more experienced ag'er to observe a brewday could help pin point any problems you may not be aware of!

we've all wasted many hours of our life brewing a dodgy batch of beer, this is ok if you learn from your mistakes and become a better brewer.

Rob.