Buildup on boil kettle lid

[catman]

I’m mid brew and just noticed this strange buildup on the lid of my kettle. I tried soap, soft scrub, and barkeepers friend and nothing can get it off (though it was brown and is now less so). What is this? Any tips on how to get it off?

 

[IslandLizard]

though it was brown

Could it have been rust from somewhere else, that dripped on it, perhaps?
Is that the inside of a kettle lid? Stainless steel?

I tried soap, soft scrub, and barkeepers friend

If BKF doesn't remove it, it's probably etched. Does it feel rough-ish?
Look at it through a magnifying glass.

Any chance it could have been Chlorine (bleach) that leaked onto it?
Or some other corrosive (to stainless steel) product?

But... I doubt that "corrosion" is going to harm anything. Just keep it clean.

 

[catman]

Could it have been rust from somewhere else, that dripped on it, perhaps?
Is that the inside of a kettle lid? Stainless steel?

I don’t believe it’s rust but I guess it could be. It’s the cheap kettle that came with my first starter kit, so i think aluminum.

If BKF doesn't remove it, it's probably etched. Does it feel rough-ish?
Look at it through a magnifying glass.

It does feel a little rough

Any chance it could have been Chlorine (bleach) that leaked onto it?
Or some other corrosive (to stainless steel) product?

I don’t think so

But... I doubt that "corrosion" is going to harm anything. Just keep it clean.

That’s what I figured—it’s not like the wort really touches the lid anyways, especially post boil

 

[MaxStout]

Perhaps something alkaline got on it. Strong alkalis can corrode aluminum.

 

[IslandLizard]

so i think aluminum

That lid is waaay too shiny to be aluminum.
Perhaps the lid is chrome plated steel? It's so shiny! Does the kettle resemble the shininess of the lid?

That’s what I figured—it’s not like the wort really touches the lid anyways, especially post boil

Yeah, just keep it clean (and shiny) and an eye on it.
Just let it dry or dry it off well after cleaning. And never lid a wet/damp kettle when storing.

 

[day_trippr]

Could easily be an aluminum lid - I have one with a lid that bright that we use for steaming lobsters - in which case that could be corrosion.
Got a magnet?

Cheers!

 

[IslandLizard]

Could easily be an aluminum lid - I have one with a lid that bright that we use for steaming lobsters - in which case that could be corrosion.
Got a magnet?

Aluminum self-oxidizes in air. It's the oxide that provides protection to the metal underneath.

Aluminum could be plated, too.

 

[Broken Crow]

From the picture, while the rivet is definitely aluminum, the lid looks to me like it could well be 200-series Stainless.. I've got a few pieces of that in kitchen and though that kind of 'fogging' did come clean with BKF, it was very resistant and took a lot of scrubbing using the BKF and the white scrub pad (Though I may have resorted to the green one...it's been a while.)

 

[catman]

My mistake—it is, in fact, stainless steel (5 Gallon Brew Kettle in Stainless Steel). Does this change anyone’s opinion on what the buildup/discoloration might be?

 

[day_trippr]

Yes - I'd more likely think that you're looking at a mineral deposit, not etching or corrosion...

Cheers!

 

[catman]

Yes - I'd more likely think that you're looking at a mineral deposit, not etching or corrosion...

Cheers!

So would the recommendation be to BKF it until it comes off? Any other tips to move a stubborn deposit?

 

[IslandLizard]

Does this change anyone’s opinion on what the buildup/discoloration might be?

Nope...

Yes - I'd more likely think that you're looking at a mineral deposit, not etching or corrosion...

That's why I suggested to look at it with a magnifying glass. If they're pits it was something corrosive to that stainless alloy, and ate some of the surface away. If they're mineral deposits, keep scrubbing with BKF and a fine grit (Scotch-type) fiber pad.

I have an older stainless kitchen pot that has similar looking "etches" on its bottom's inside surface. But it's all shiny (and very clean) now, after some polishing work with BKF.
IIRC, that pot had contained an oxalic acid solution that was forgotten about after a wood (furniture) restoration project over 3 decades ago...

 

[whattabrau]

Can you gently scratch it larger with your fingernail? The photo looks like a plastic protective film has started degrading. Of course I've never accidentally used something for years with a plastic protective film still on it, but I heard it happened to friend of mine.