When the manufacturer recommends you passivate with something like Star San, does that mean fill the entire 20g kettle? Or just maybe 4g and apply with a sponge to the rest? Just wondering if I need a big bottle of Star San.
Passivation - fill the entire kettle?
- Thread starter pretzelb
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Don't fall for the idea that starsan is an appropriate for passivation. Get some Citric acid. The ratio is 1 LB of citric acid per 2 gallons of 150F water. It should be in contact for about an hour which either means filling it all the way or running it through a CIP ball.
Not everyone has CIP. There must be other ways, especially for larger kettles. Even for a 10 gallon kettle, that's still a lot of acid.
How about mopping the citric acid solution on, continuously, keeping the surface wet?
Or laying the kettle on its side in a trough or lay a soaked rag on the "bottom" and keep rotating?
Now the citric acid solution can be recovered and stored for reuse, but 20 gallons of it?
Yeah, tipping it against something so that the entire side is submerged will do it. You'll spend half a day of it, and will have to keep reheating, but it will work.
pretzelb
Well-Known Member
Since I don't have any, and I don't have CIP, that would mean 10 lbs of citric acid. Fwiw, the ones recommending Star San is As Brewtech in their instructions.
RPh_Guy
Bringing Sour Back
Read this for thorough and accurate information regarding passivation:
https://modernbrewhouse.com/wiki/Passivation
Filing the kettle is probably the only practical way to passivate since you don't have CIP.
NO Star San.
https://modernbrewhouse.com/wiki/Passivation
Filing the kettle is probably the only practical way to passivate since you don't have CIP.
NO Star San.
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I'm aware that SS recommends using StarSan but that won't passivate. It's not worth spending up all the starsan to be honest. Just give it a good wash out with dish soap or hot PBW. If you get any spot rusting at any of the kettle welds, hit those with Bar Keeper's Friend.
You can get 10# of Citric Acid from Alpha Chemicals for $14.50 plus (quite reasonable) shipping.
The used passivation liquid can be stored for repeated (future) use, I doubt it will go bad at that strength. I had some "white clouds" (looking like suspended cotton wool balls) form in a bottle of (odorless) photographic Stop Bath concentrate, but it still worked fine, as was the pH of the working solution. It may have been buffered somewhat.
The used passivation liquid can be stored for repeated (future) use, I doubt it will go bad at that strength. I had some "white clouds" (looking like suspended cotton wool balls) form in a bottle of (odorless) photographic Stop Bath concentrate, but it still worked fine, as was the pH of the working solution. It may have been buffered somewhat.
RPh_Guy
Bringing Sour Back
Do you guys successfully store your citric acid solutions for a year or more? Citric acid is a nutrient for microbes.
I don't recommend BKF in surfaces that will contact wort/beer, for reasons explained in the article linked above.
I don't recommend BKF in surfaces that will contact wort/beer, for reasons explained in the article linked above.
I have a new kettle on the way and was going to use StarSan, as per instructions, to passivate.
Do you mind giving a little more instruction on why it won't work? Given that the manufacturer says we should, it'd be super helpful if you could explain why this simply won't do what we think it does... thanks!
RPh_Guy
Bringing Sour Back
Apologies, I missed that. Thanks for responding!
You can get a big bag of citric acid crystals from Amazon inexpensively...
Cheers!
Cheers!
This article is great. The website also has a good article on cleaning stainless
https://modernbrewhouse.com/wiki/Cleaning
I have a SS kettle that I've always used kitchen steel wool and dish soap on... maybe I'll give it some TLC, and I certainly won't do this to my new fermenter!!
I think just keeping all surfaces wet, by occasionally sloshing the citric acid around, should do it. 5% citric acid (just like lemon juice, but as somebody pointed out, if you need more than a cup then making your own 5% solution from citric acid makes sense economically) at 140F for an hour should be plenty, if I remember correctly.
And just to be clear, the citric acid removes the free iron from the surface; the actual passivation, formation of chromium oxide, happens afterwards, upon exposure to air.
And just to be clear, the citric acid removes the free iron from the surface; the actual passivation, formation of chromium oxide, happens afterwards, upon exposure to air.
RPh_Guy
Bringing Sour Back
There's a lot of scientific evidence that says high temp improves effectiveness.
That's why I said 140F.
I found 150°F as the general recommendation.
Also, first rinse should be as mineral-free as possible, with DI recommended followed by RO water. After that any water will do...
Cheers!
Also, first rinse should be as mineral-free as possible, with DI recommended followed by RO water. After that any water will do...
Cheers!
RPh_Guy
Bringing Sour Back
From where?
Jeeze, that was some time ago, but I had wandered around for over a week in spare time looking for general and then specific recommendations, and 150°F came up as the sweet spot. Some of the sites were institutional, others were SS fabricators, that much I remember.
Anyway, that's what I've been using, along with 5% CA by weight. It did an amazing job on my SS IC after I had brutalized it while threading 1/8" thick SS wire through it in three vertical runs to gap the coil (which prior was basically a 10" diameter solid cylinder). Also treated my SS spider to it (fit right inside the IC) and it looked better than new...
Cheers!
Anyway, that's what I've been using, along with 5% CA by weight. It did an amazing job on my SS IC after I had brutalized it while threading 1/8" thick SS wire through it in three vertical runs to gap the coil (which prior was basically a 10" diameter solid cylinder). Also treated my SS spider to it (fit right inside the IC) and it looked better than new...
Cheers!
It's not the cheapest operation, but I will do both my kettle and new fermenter at once... so I can move the liquid back and forth, with the kettle being able to re-warm it as it cools. May try not making as much as keep it moving, but that makes me feel like it won't really work, just to save $10.
Now I just need to decide how I'll give my old kettle a nice deep clean before doing it. I have lots of OxyClean (works wonders to take pee smells out of clothes.. KIDS!!!), maybe I'll use that.
Now I just need to decide how I'll give my old kettle a nice deep clean before doing it. I have lots of OxyClean (works wonders to take pee smells out of clothes.. KIDS!!!), maybe I'll use that.
This might be a good document to look at: http://www.galvanizeit.com/uploads/resources/astm-a-967.pdf
Somebody (RPH?) posted a talk from a NASA dude who didn't agree 100% with the engineers in Conshohocken (not making this up, that's the name of the town; apparently it means 'pleasant valley').
I wouldn't go overboard with this whole passivation thing; unless you have a reason to believe your equipment was machined with the wrong tools that embedded a lot of non-stainless steel in the surface of your stainless, or some weird stuff happened while welding, stainless should just passivate itself.
I like to scrub my cooking and brewing pots once in a while with lemon juice while they are still warm, just because it makes me feel good. I don't think it's strictly necessary.
Sanitizing, on the other hand, I firmly believe is.
Somebody (RPH?) posted a talk from a NASA dude who didn't agree 100% with the engineers in Conshohocken (not making this up, that's the name of the town; apparently it means 'pleasant valley').
I wouldn't go overboard with this whole passivation thing; unless you have a reason to believe your equipment was machined with the wrong tools that embedded a lot of non-stainless steel in the surface of your stainless, or some weird stuff happened while welding, stainless should just passivate itself.
I like to scrub my cooking and brewing pots once in a while with lemon juice while they are still warm, just because it makes me feel good. I don't think it's strictly necessary.
Sanitizing, on the other hand, I firmly believe is.
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pretzelb
Well-Known Member
Well shoot. I bought some from Amazon but at about double that price.
RPh_Guy
Bringing Sour Back
You might want to check out the linked article I wrote ... I reviewed not only latest version of ASTM A967 (2017), but also all the relevant literature, including multiple scientific studies looking at surface chromium percentage.
I also describe the various reasons why it can be beneficial to passivate (with numerous expert and scientific references).
What's "necessary" is simply a matter of philosophy, but hopefully this article can help people make an informed decision with regard to passivation. I have led the proverbial horse to water.
Cheers!
If you can find a large heavy mass to put in the kettle, it would reduce the amount of liquid needed to fill it.
Trivot in the bottom, then a smaller kettle filled to the top with water.
Almost too simple, I was thinking along those same lines.
Another, somewhat smaller kettle, a large bucket or container. Heck, even a sturdy plastic bag filled with sand, gravel, or bricks, etc.
Maybe a full keg?
pretzelb
Well-Known Member
That might work since it would fit inside the round heating element. Would citric acid wear out the rubber / plastic bottom of a keg?
