Anybody got any information on this? I've made up 15L of 5% solution for cleaning stubborn grime on some bottles. How long can I keep using it?
Caustic is unlikely to change over time!
It may well become diluted and have its pH changed by anything acid but caustic is caustic and stays a single compound!
Unlike Chlorine and Oxygen based products:
VWP and Bleach/Vinegar: The chlorine will come out of solution and its the chlorine that's the sanitiser
Oxybased cleaners like Lidl W5(perCarbonate) and perAcetic loose the mon-atomic oxygen very quickly. It is the O+ ion that is the sanitiser.
However your good old campden tablets are also a nice simple sanitizer that improves with age 9but again not dilution).
Campden tabs when disolved form a solution of Sulphurous Acid (H2SO3) this can oxidise to the much stronger Sulphuric Acid. This last para is a bit contentious these days but it was what I was taught!
Thanks Will. I've a lot of grimy bottles that need soaking so several rounds on the same batch of caustic is good news.
Is 5% enough to do much? Its 500ml caustic in 20 litres hot water for the caustic wash with CIP.
Quote from: Hop Bomb on June 07, 2014, 08:17:49 PM
Is 5% enough to do much? Its 500ml caustic in 20 litres hot water for the caustic wash with CIP.
Now that's another question and one I don't have an answer for!
5% caustic is not nice stuff - just ask your clothes or your fingers!
Seriously tho':
You can buy some VERY dangerous chemicals in the DIY stores:
Like Solid Caustic Soda pellets and also 90 odd% conc. Sulphuric Acid (Both sold as drain cleaners)
Unless you REALLY know what ye's doing with these Beware!
2% is the recommended dilution rate IIRC
A brewery would use a solution of 3% caustic for vessel cleaning so I wouldn't worry if it got diluted a bit for bottles. If possible and you get to much sediment in caustic solution then try de-sludge the bottoms. Also protect your eyes.
And your hands/arms-very handily takes a layer of skin off
(http://upload.wikimedia.org/wikipedia/commons/0/09/Sodium_hydroxide_burn.png)
OUCH! :o
That looks nasty. Where are your gloves & goggles?
Is brewers caustic & caustic soda different? 500ml brewers caustic per 20 litres here. 4 to 5 of those buckets to a 2000L tank for the caustic wash.
Quote from: imark on June 07, 2014, 07:43:05 PM
Thanks Will. I've a lot of grimy bottles that need soaking so several rounds on the same batch of caustic is good news.
you need some bottles, i could drop you down 30+ brown 500ml btls, all nice n clean.
Thanks for the offer but I've loads of them. The ones I'm scrubbing are my heavy gueuze bottles.
Yeah. They're the ones alright. Labels are a bitch to get off.
Quote from: imark on June 08, 2014, 11:17:27 PM
Yeah. They're the ones alright. Labels are a bitch to get off.
After a soak I use a stanley knife and plane off the label and glue in strips it works a treat. Sometimes it even works better on a dry label (gypsy labels particulary)