Summary for edta attack stainless Discussion
EDTA attack stainless is the core question from a hobby brewer who wanted a non-toxic, closed-loop sanitizer for a small microbrewery and worried that strong EDTA might strip chromium oxide or create pores in stainless steel by attacking the iron. In the reply, the answerer says that a mixture of citric or gluconic acid at 2-3% with EDTA at 0.5% is widely used to clean stainless steel heat exchangers, implying that this combination is considered suitable for stainless cleaning. The answer also notes that if a deeper clean is needed, a hot solution of 10% sodium permanganate and 3% caustic soda can be used first. The excerpt does not directly state whether EDTA alone will attack stainless, but it suggests that EDTA in the cited cleaning mix is commonly used on stainless equipment.
February 25, 2013
Q. I have a little personal microbrewery I built. There are a lot of Stainless parts to keep clean: 3-way valves, integral chiller, tubing, connectors, vessels etc.
I’ve been thinking that my cleansing and sanitizing regimen would be so much more relaxed if I were able to close the system up after a washdown with some non-toxic sanitizing agent in it and just rinse that away on brew day.
A strong aqueous solution of EDTA would definitely stop anything from growing. But would it also strip away the Chrome Oxide or create micro pores in SST as it attacked the iron?
Cliff R [last name deleted for privacy by Editor]
hobby brewer – North East USA
March 1, 2013
A. Hi Cliff,
Have you tested citric or gluconic acid (2-3%) and EDTA (0,5%)? It is widely used to clean stainless steel heat exchangers to use this combination.
If you must clean thoroughly (and the first option is not enough), you can use: First a hot solution of 10% sodium permanganate and 3% caustic soda ⇦liquid caustic soda in bulk on
Amazon [affil link]
(both toxic, but very effective cleaning stainless of everything), then rinse with tap water and then wash with the solution of EDTA and citric or gluconic acid. This is not a non toxic solution to your problem but will do the trick!
The citric (or gluconic) acid renews the chrome oxide layer so your equipment doesn’t deteriorate.
Hope this helps you with your brewery! Next year I hope to be joining the brewing community ;)
Regards,
Daniel Montañés
– Cañuelas, Buenos Aires, Argentina