Dark spots, ? beer stones in the bottom of my keg...What to do?

A while ago I had a beer that after while started tasting funny, like a little bit too sweet. Not sure if it was bad or not. The keg I used with that beer, I noticed had two small reddish rust color spots in the very bottom. Not sure if they were two spots of rust or beer stone. I Cleaned the keg with my key cleaner using PBW, And then sanitized it. Looked in and those two little spots were still there. Then I soaked it in PBW overnight and still there. Most recently I put beer stone remover near 100% strength and layered the bottom of the keg with it for several hours and then put my arm down there with a scrubber and scrubbed and it’s still there. Left the beer stone remover in it overnight and those two spots are still there. Not sure if these spots are beer stone or two little spots of rust and if it could possibly be a source of ongoing infection.? Any ideas?  I’m worried to put another beer in the keg now.

Try Barkeeper’s Friend.  Good chance it will remove the spots and repassivate the SS.

You might need an extended period of soaking.  I have soaked kegs a week to remove beerstone, which for me was more of a whitish scaly looking deposit.

An acid wash will remove beer stone.  I got some from a dairy supply store but you can also soak with a solution of Star San at a concentration of 1 oz. per gallon of water and see if that removes them.  The acid soak will also re-passivate the stainless steel.

Barkeepers Friend is oxlaic acid and would also work.  the problem is scrubbing it on the bottom of the keg and I do not know the ratio of the powder to water for uusing it as a soak (Denny?).  When I have used it on my keggles, I put it on a damp Dobie pad, scrub the stainless with it, and allow ity to sit on the stainless for about 5 minutes before rinsing it off.

$15 at a Tractor Supply. It’s good stuff.

This is timely because I just started getting medieval on my kegs.  My water is on the hard side and beerstone or just hard water deposits will accumulate.  I have not seen ‘red’… for me it’s white and rough like sandpaper.  If what you’re seeing is beerstone, something acidic should work… like Starsan.  What I have been doing is cleaning the keg out with the hose and then dropping 5 tbsp of LD Carlson EasyClean in there.  I find it to be much more effective than Oxi or PBW.  Then I boil 5 gallons of water and add that to the keg using a funnel and I leave it overnight.  I dump it out and then reach into the keg (I’m not exactly Mr. Universe) with some plain steel wool and scrub anything that seems to still be there.  It comes off easily.  I have 10 kegs and I have done this now on 4 of them.  When done, the insides of these kegs sparkle as if they were brand new.  I have also taken the pressure washer to a couple that needed some extra punishment.  If it’s rust you’re seeing, I might retire that keg.

You can’t really use BKF as a soak.  You need to scrub.  I have a long handled brush I use for scrubbing the bottom of kegs.

Try Craftmeister Alkaline and hot water.  That stuff will clean anything.

I mentioned elsewhere that I used EasyClean years ago and I noticed that it removed things that other cleansers didn’t seem to.  There were also warnings on the container about using impervious gloves and safety goggles when you handled it… which seemed a little scary.  Those warnings are no longer on the packaging but it still cleans very well.  I had a cobra tap with tubing that looked stained.  I tried using Oxi with hot water and PBW as well without luck.  I filled the sink with hot water and EasyClean and started a siphon into a bucket on the floor.  I watched as amber-colored flakes started coming off the inside walls of the tubing.  After 15-20 minutes of that the tubing looked brand new.  The guys on The Biergarten compared the ingredients to PBW and declared them the same but there is something different about EasyClean.

Well, that’s why I didn’t recommend Oxi or PBW.

I thought you were an Oxi fan.  For general-purpose cleaning I feel like it’s okay.  But if you have a tough cleanup job, I’m not sure it’s up to it.  I have always been focused on good sanitation but there are times when I’m looking at other things and I assume my cleaning and sanitation are fine.  A few weeks ago I closely examined an empty keg and noticed I needed to get a little more serious about keg conditions.

As far as the OP goes… if it’s beerstone Starsan should absolutely do the trick.  If you use whichever cleanser you prefer plus some boiling water (you don’t need much if the spots are on the bottom) and it still doesn’t come off, I think I might stop right there.  If you can get your arm all the way in and use some steel wool on the spots, you might learn more about what they really are.

Oxi is OK.  PBW is better. Craftmeister Alkaline kicks both their butts.

So you use the Craftmeister for general-purpose cleaning or only for tough jobs or what?  I feel like if you used it all the time then there would be no “tough jobs”.  :P  I’m digging this EasyClean but I’m always open-minded about good products.  Cheers.

Way back when it was said not to use steel wool on Stainless. You can deposit iron from the steel wool onto the stainless.

Is that only for kegs or stainless in general?  I have stainless appliances and a stainless cooktop and steel wool was mentioned as the only material to be used to clean it.  My wife occasionally uses a green pad on our cooktop and there are scratches from that.  When I used steel wool on stainless it always cleans beautifully without scratching or discoloring.  I should also mention that this routine of mine is not something I would do EVERY time I had an empty keg.  Just an occasional jolt to my regular cleaning routine.  Thanks for the information.

Kegs and fermenters was what they talked about. Iron in you beer, even if you don’t taste it, will cause stalling.

Ken Grossman talked about this in Portland IIRC. Sierra Nevada will do more passivation to get iron to lower levels.

This has a caution against vsteel wool, and a couple of other nice tips.

https://www.probrewer.com/library/used-tanks/the-care-and-feeding-of-stainless-steel/#:~:text=Never%20use%20steel%20wool%2C%20which,their%20beer%20in%20soda%20kegs.

And John Palmer’s $0.02 on it.
http://howtobrew.com/book/appendices/appendix-b/passivating-stainless-steel

Interesting and thanks again.  I will keep an eye on these kegs that I cleaned to see how they hold up.  Since Palmer suggested a green pad instead of steel wool, I feel like I could use that and get the same results without damaging the inside of the keg.

Also… to the OP:  my apologies for the thread-jack.  :wink:

I use Craftmeister Oxygen for “normal” cleaning.  I use the alkaline for rough stuff or if I don’t have hot water available.  The Alkaline works better in cold water than PBW works in hot water.