Causic Shelf Life

[Finite]

Hey team,

Im in the process of packing all my brewing gear up for a move to a new unit and have a bottle of liquid caustic that I made up in high concentration from granule form. Its been kept in a sealed air tight container but hasnt been used for about 10 months. I use it for general cleaning of my equiptment.

Whats the word on the shelf life of this stuff, is it still usable?

 

[ausdb]

Hey team,

Im in the process of packing all my brewing gear up for a move to a new unit and have a bottle of liquid caustic that I made up in high concentration from granule form. Its been kept in a sealed air tight container but hasnt been used for about 10 months. I use it for general cleaning of my equiptment.

Whats the word on the shelf life of this stuff, is it still usable?

Do you have a pH meter or test strips?
I have left a sink full of bottles with pretty strong caustic in it (Originally I think I made it up at about 4-5%) for a long time about 6 months. I cleaned it out just before Chrissy and it was still at pH11-12 or more but it was hard to tell as it was pretty murky (using test strips), it was however strong enough to quickly get that soapy feeling on bare hands as it dissolves your skin h34r: .
Maybe one of the commercial guys could chip in here as I have been wondering the same thing. I have read in commercial food production situation where a caustic solution is used to peel stuff that it is recycled, the crappy bits get filtered out and it gets more caustic added to ring the pH back up but is not completely dumped all the time.

 

[Kai]

I don't think it would degrade much, however I'd be more concerned about transporting it. I hope you have a very well-sealed container. I'd be more comfortable just throwing it out and getting more. Caustic isn't expensive.

 

[newguy]

It should be okay. Commercial keg washers found in breweries will recycle their caustic so I don't think that storing it in solution will hurt it at all.

 

[dr K]

Pour it down the drain, its likely still very potent and as Kai said..don't transport it, $3 worth of NaOH in a concentrated solution can cause some bad shit if it spills !!

K

 

[MHB]

Actually Caustic degrades quite quickly if there is CO2 around (or it's exposed to air). Fortunately it converts from Caustic Soda to Washing Soda, another very useful cleaner. I think you will find that in small commercial applications Caustic is mostly a use it and loose it product, in large CIP systems great lengths are gone to, to avoid contact with CO2 - or the product does degrade.

A couple of other points to be aware of; over time it will dissolve glass so HDPE is the best type of container.
You definitely dont want to use a pH meter in Concentrated Caustic - some types of sensors will be attacked and will loose accuracy.

Similarly with indicator paper strong; Caustic can digest them, remember that the pH scale is logarithmic so the difference between a pH of 12 and 14 isn't 2 times as strong it's more like 100 times as strong.

Just be really careful with Caustic, I wouldnt take any risks to save a couple of dollars.
More importantly from the above I get the impression that before using hazardous chemicals, it's a really good idea to find out a bit about the products.

MHB

 

[Back Yard Brewer]

Actually Caustic degrades quite quickly if there is CO2 around (or it's exposed to air).

I can vouch for the air scenario. I had a kick arse big bag (10kg) It sat wraped up in my shed cupboard inside a meatkeeper and it did all soughts of wierd and wonderful things. It sweated,the vapours it let off in the cupboard formed into risidual white powder and generally just made a mess. I now have a lot of washing soda. Caustic is not all that expensive to buy from a hardware shop and it comes in a nice size sealable container.

BYB

 

[ausdb]

Actually Caustic degrades quite quickly if there is CO2 around (or it's exposed to air). Fortunately it converts from Caustic Soda to Washing Soda, another very useful cleaner. I think you will find that in small commercial applications Caustic is mostly a use it and loose it product, in large CIP systems great lengths are gone to, to avoid contact with CO2 - or the product does degrade.

A couple of other points to be aware of; over time it will dissolve glass so HDPE is the best type of container.
You definitely dont want to use a pH meter in Concentrated Caustic - some types of sensors will be attacked and will loose accuracy.

Similarly with indicator paper strong; Caustic can digest them, remember that the pH scale is logarithmic so the difference between a pH of 12 and 14 isn't 2 times as strong it's more like 100 times as strong.

Just be really careful with Caustic, I wouldnt take any risks to save a couple of dollars.
More importantly from the above I get the impression that before using hazardous chemicals, it's a really good idea to find out a bit about the products.

Thanks Mark most helpful post,