PBW residue or Brewer's(ing?) Stone

Hi everyone,

I have a stainless conical fermenter and over time this white residue has built up on the inside.

This fermenter is cleaned with PBW and is rinsed VERY well and scrubbed out lightly after the PBW cleaning. But I usually do not give it a real course scrub.

Whatever this stuff is if I really go at it with the course side of a soft scrub sponge it cleans up somewhat.

So does anyone know what this is? Is it PBW residue? I've read about brewers/brewing stone that is protien buildup on the inside of your equipment. Could that be it?

Am I doing something wrong that is encouraging this stuff to accumulate?

Thanks for the help! Any advice is welcome.

Brewing stone takes a while to develop. Does it feel "chalky"? If its PBW it should rinse right out. Brewing stone can be removed with a 1/10 acid solution or elbow grease. I dont think its brewers stone because it would develop (usually) on a flat horizontal surface.

Yes it is kind of chalky and rough. I've had the conical for a few years now and I've noticed it getting progressively worse, but only at this particular level in the fermenter. I noticed something similar on the dip tubes in my keg as well. Elbow grease seems to remove it.

I work at a brewpub and one of my duties is to clean the beer stone from the kettle after every brew. It completely covers the kettle and looks exactly like whats in your pics. I use an S.O.S. pad and elbow grease and it works great. Just dont use the ones that have the soap in them. Not sure what kind of soap it is so im not sure what it would do to the beer. Btw beer stone is a calcium buildup, not protein.

Undiluted vinegat should clear it right up!

A probrewer friend gave me some acid wash (from Five Star). I don't use it that often, but when I do a deep cleaning I do the alkalai wash first (PBW), rinse well, and then use the acid wash, rinse well. It cleans that up very nicely. He also told me that the acid wash is used for stainless passivation.

You can also buy stuff specifically formulated to remove beerstone, it's usually just called beerstone remover. Milkstone remover is apparently the same stuff, too. Or use acid cleanser in addition to your basic (PBW) cleanser and it'll go away.

Wouldn't StarSan solution (which is acidic) remove it? What do you use to sanitize?

PBW has chelating agents to prevent that type of build-up (Oxiclean Free does not) so I seriously doubt it's PBW.

Thanks for the help. I'll try some acid cleaner and see if it clears up.

I see this is very old but I wonder if CLR will work, I only have the typical brown stuff on boil kettle. CLR is advertised to clean coffee pot so thought that may work.

PS I suspect you have hard water to get that scale on a fermenter is my 2 cents.