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bpdevlin
03-11-2016, 09:27 PM
Is anybody here using just citric acid as a descaler / caustic neutralizer in fermenters?

I've been using it for minor passivation & cleaning jobs (in a spray bottle), and it seems to remove minerals reasonably well. I will follow each acid rinse with PAA, so I assume there won't be any flavor left on the beer.

lthendricks8
05-01-2016, 08:50 AM
Is anybody here using just citric acid as a descaler / caustic neutralizer in fermenters?

I've been using it for minor passivation & cleaning jobs (in a spray bottle), and it seems to remove minerals reasonably well. I will follow each acid rinse with PAA, so I assume there won't be any flavor left on the beer.

I use it for passivation, but only because I can't get my hands on nitric where I am without going through a ridiculously ornate and overly complex licensing process. It's relatively inexpensive, but you have to use about five times as much or run everything at a higher temperature/longer times. I use it in conjunction with phosphoric for acid rinses on my equipment post caustic every few cycles. But I'd much rather have nitric.

Tim DHBC
05-31-2016, 04:24 PM
I came across this article from NASA about passivating 304 Stainless with Citric Acid. From what I could understand it seams that a 4% solution at 140 for 2 hours worked well. Anyone else have any information on this?

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110001362.pdf

dick murton
06-01-2016, 02:20 AM
I found an article by or on behalf of ASME (or some such) and also this one http://www.bssa.org.uk/topics.php?article=68

But I think the original question was about caustic neutralisation. I have not used citric acid for this role, but acid detergents, whether nitric or phosphoric based, are a blend of acids and surfactants etc, so will do the job more effectively than simple non blended acids of any sort. Nitric and phosphoric detergents may also be combined with sanitising agents, so although you have to rinse, you don't have to use PAA or similar, so you save time, water and perhaps a little reagent money (oh, and they are a little easier to handle than PAA). I would have thought that straight citric acid usage would mean it is actually more expensive to use overall, but obviously I can't confirm that from experience.

roc-craven
06-03-2016, 10:26 AM
I know the NASA engineer in the report. If you have any specific questions I can ask him for you.

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