Passivation of SS fermenter

[Braufather]

I am thinking about upgrading to a SS brewbucket( again) and noticed there seems to be a bit of prep before first use- what do people use to cleanse and passivate?


Cleaning - it says Tri-Sodium Phosphate (TSP) - no idea what this is- can you use PBW instead?


Passivating - looks like star san would work out expensive at that concentration - does anyone use citric acid?


https://ssbrewtech.zendesk.com/hc/e...hat-acids-can-I-use-to-passivate-my-Stainless.


Also while we are on the subject does anyone passivate their kettle or cornies as well?

 

[Clint]

I asked when I bought my two kettles from maltmiller. ..he said give them a good clean with oxi;rinse and they're good to go.

 

[terrym]

It is my understanding that you do not need to actively passivate good quality stainless steel. It will self passivate in the presence of air or aerated water (say out of the tap). If the passivation layer is removed by mechanical damage it will re-pasivate when exposed to air again. The brewing process itself will not corrode SS assuming the equipment is manufactured from the correct grade e.g type 304L
If SS shows signs of rusting then the base metal is contaminated with carbon steel, and that implies poor quality SS has been used. In that case chemical treatment to remove the CS inclusions may be necessary, but when that is done there is no need for further treatment.
That said I would not use chloride/chlorine based cleaning fluids with type 300 SSs because chlorides can, under certain conditions, cause corrosion.
Anyone know different?

 

[foxbat]

Oxi will probably work. TSP is recommended because it's a strong degreaser that'll definitely get rid of any engineering grease residue left over from manufacturing. You can get it as a powder on ebay. I use it once-only on SS kit when it arrives. I did passivate my SS kettle with Bar Keeper's Friend (Oxalic acid) because I had some under the sink. Maybe it's not necessary but it only took 5 minutes.

 

[-Bezza-]

I don't "know" different but was, by coincidence, looking into some aspects of stainless steel today as I was ordering a big stock pot to do some BIAB.

I was starting my research by understanding what 18/10 and 18/8 meant and whether I needed my pan to have this. Short answer is yes, this is the good quality stuff and also the 304 stuff you refer to and the stuff the SS Brew Bucket seems to be made of.

See here: https://www.bssa.org.uk/topics.php?article=91
And here: https://mightynest.com/articles/stainless-steel-all-about-food-grade-304-188-and-1810

This link confirms that Terrym says above, i.e. that passivation occurs naturally in the high-grade stainless steel: https://www.bssa.org.uk/topics.php?article=68

Which also seems to be supported by the Brewtech link you have provided

Remember that passivating stainless steel is a way of renewing the corrosion resistance performance of the base metal and improving its longevity.

So on the basis that 304 steel sorts itself out and you only need to introduce the acids when performance is deteriorating.

In terms of chlorine-based treatments, I found this: https://www.bssa.org.uk/topics.php?article=38

There's a lot of reference to 316 steel, which is the highly-resistant outdoor stuff. I do however infer from this that diluted chlorine-based products that are only temporarily in contact with the stainless steel would be effective.

I'll also ask if anyone knows any different as I don't want to mess up my 304 SS pan?

 

[aamcle]

Scrub it, dry it, any cleaner (nearly any) will do when it's clean and dry leave it to "Air" for a couple of days and atmospheric Oxygen will have done the job.

aamcle

 

[Sadfield]

Bar Keepers friend should both clean and passivate. Quite cheap at £2.50 a bottle.

http://beersmith.com/blog/2017/01/0...rosion/?utm_source=dlvr.it&utm_medium=twitter

 

[Dutto]

..............

If SS shows signs of rusting then the base metal is contaminated with carbon steel, and that implies poor quality SS has been used. .............

... or someone has used a non-SS wire brush or non-SS wire pad to clean the vessel.

The favourite mistake is to use a Brillo Pad because it is readily available and has an inbuilt detergent that will remove the surface grease/oil which lubricates the mould used to shape the SS vessel.

The problem is that minuscule carbon steel fragments get trapped in the surface cracks and blemishes of the SS and then turn rusty.

How do I know this? I once used a non-stainless steel brush to clean up some of the TIG welds that held a stainless steel canopy frame together on my boat. They all looked perfect until the rust started to form at which time a mate of mine pointed out the error of my ways; luckily before I started welding up the boat's railings!

 

[-Bezza-]

Just sharing the link from How to Brew on cleaning stainless steel: http://howtobrew.com/book/appendices/appendix-b/brewing-metallurgy

Has some suggestions on specific cleaning products, including PBW as per @Braufather 's original question.

Having read that, I'm now minded to completely avoid anything chlorine-based so VWP is out!

 

[Braufather]

thanks for the replies. quite varied so still a bit unsure. i have bar keepers friend kicking about so might give that a try for passivating and pbw for cleaning . only thing with bar keepers friend is it can also remove the etchings if you are not careful i read.

 

[Dutto]

Chlorides only attack SS at higher temperatures; and even then they cause what’s known as “crevice corrosion”. If there was a major problem then almost all modern boats would sink due to the Chlorine in salt (NaCl).

 

[terrym]

Chlorides only attack SS at higher temperatures; and even then they cause what’s known as “crevice corrosion”. If there was a major problem then almost all modern boats would sink due to the Chlorine in salt (NaCl).

I thought marine grade SS was type 316 which has better corrosion resistance to chloride induced corrosion than type 304 more commonly used for brewing equipment.
In addition to crevice corrosion, chlorides will cause pitting corrosion, and stress corrosion cracking in austenitic SS under the right conditions.
A quick Google for 'chloride attack on 304ss' revealed this amongst others
http://nem.org.uk/rust2.htm
If I had spent a wodge of cash on shiny I would avoid chloride/chlorine based brewing liquids however minimal the risk, there's other products out there that do the job just as well
But for folks who own lots of shiny they will, undoubtedly, decide for themselves. :thumb:

 

[Dutto]

I have a 15 litre SS pot that I bought nearly thirty years ago to boil up the cockles, mussels and oysters that we collect out in France.

Here at home, I use it as a vessel to marinate Beef in brine (corned beef), steep Pork Belly in brine before smoking it to make bacon, marinate fish in brine before smoking it.

For the Corned (Salt) Beef the salt concentration is high enough to float an egg and the beef sits in there for a week before it is rinsed and boiled.

After 30 years of use there is no sign of any pitting or crevice corrosion so I also use it to mix up the LME whenever I’m doing a kit.

Plus, my home is littered with cooking equipment made from SS. Three-tier Steamer, Sauté Pan, Milk Pan etc and none of them are suffering from any corrosion or pitting despite using them with salt and occasionally cleaning them with bleach.

Yes, it can happen but I noticed in the article that showed the ruptured cheese pipeline there was no indication of the time it was in service or the temperature it was running at; both of which are critical corrosion factors.:thumb:

 

[cerberos]

Oxalic acid is available on ebay.

 

[-Bezza-]

I was reading Palmer on this, as edition 4 of How to Brew has a lot more info. He suggests it's ok to use chlorine-based products for short periods of time but seems to effectively be saying why bother when there are other more suitable things available. It's a point that was made in an earlier post and one that I think makes complete sense.

In fact, even from edition 1: "It is best to not use bleach to clean stainless steel and other metal. There are other cleaners available that work just as well without danger of corrosion. The percarbonate-based cleaners like PBW are the best choice for general cleaning."

 

[Clint]

My set of stainless pans is 21 years old;bought them when we bought the house. Apart from a few dinged lids they're as good as new...I cook most days using at least a couple of them. Some even go from hob to oven...and I forget they're screaming hot....

 

[Dutto]

This is my +30 year old SS pot.



I stuck the magnet on the side to show that it's "low grade" SS and still not cracked or pitted despite being used for all kinds of service (including salt) for over 30 years!

PS

Hopefully, by the end of this month I will be planning to take the pot to France for the Spring Oysters ...

... and by the time I get back in June the Premium Bitter (on the shelves at the back of the pot) should be fully conditioned and ready to drink! :thumb:

 

[-Bezza-]

Like the idea of the slate / chalk board strip on the front of the shelf! :thumb:

 

[foxbat]

Like the idea of the slate / chalk board strip on the front of the shelf! :thumb:

There's not much in the 'Premium bit' though. I think he needs to raise his standards :) :)

 

[djheaton321]

I used the TSP recommended by SS Brewtech, bought it off ebay. Barkeepers friend its ok but I don't use it on SS fermenters, it is a bit too abrasive. Be careful about using oxi cleaner if you have hard water, you will end up with deposits on the fermenter. I also use the PBW to clean it, not cheap but you don't have to do any scrubbing at all if you leave it to soak. Bleach products will pit the surface over time.