Strange Stubborn White Residue/Film on Inside of Glass Carboy

[BDough]

Hi All,

Looking for any advice on taking out a very stubborn coating on the inside of my 6-Gal carboy. Haven't brewed in this vessel since the coating first manifested, but looking for any guidance. See pictures below.

Further Information:

• I have tried the following means of removal
  • 5 Star PBW
  • CLR Lime and Rust remover
  • Dish Soap
  • Hot tap water
  • Moderate concentration Vinegar solution
• I have not tried
  • DI/Distilled Water
  • Typical Organic chemical solvents (Isopropanol, acetone, Peroxide, etc.)
• Each method I've tried has exacerbated the extent to which the vessel is coated with this film/residue.

Any assistance is greatly appreciated.

 

[D.B.Moody]

Now before I answer I just have to say that I am impressed by your vocabulary and your ability to post a coherent question.
Secondly I have to remark upon your restraint in asking for help as this is only your third posting since you joined in 2019.
Answer: YIKES! That is some serious crud.

I assume I am seeing brush marks that indicate it can be dislodged. Usually white residue is a mineral thing, and, unfortunately, vinegar is a go-to for that.

What did you have in that when it showed up? From the pictures it looks like it came down from around where the bung would have been. Was there something in there that had a very aggressive fermentation and a strange make up?

 

[sibelman]

I've seen etching in a glass carboy (from dried Oxi or PBW) that simply can't be removed. But not in that kind of drip-from-the-rim pattern. Gotta be a story there. Some odd cap/plug/bung that releases, er, something nasty.

Are you saying that more has appeared as you've tried to clean it?

 

[khannon]

Have you tried attaching one of the bendable nylon brushes to a drill? Wetting the brushes or filling the carboy with any of the above and spinning?

How much time did you give said solutions? I'm not sure about mineral, but I've found a bleach solution, filling them, and leaving in the sun for a day or two works wonders for alot of things. Plenty of rinsing etc.. afterwards.

 

[Broken Crow]

I had a residue in a carboy that was nowhere near as bad as yours and I was gonna either get it out or toss it. I ended up using heated undiluted vinegar, repeatedly soaking overnight and then bending [to the point of destruction] a carboy brush. After three or days of repeating this, it was finally clean. I'm only guessing, but it is possible that yours may have began looking as mild as mine and some chemical reaction with a cleaning attempt has simply made it more visible. I can only offer my suggestion of patience, warm undiluted vinegar or citric acid, time & elbow grease... or just replace it..BUT since this may ignite a ton of recommendations on replacements, I will add my 2-cents that I love the Fermonsters for their easy hadling and cleanability.
Best of Luck.

 

[Dr_Jeff]

Carboy, meet Mr. 9mm.

 

[BDough]

Now before I answer I just have to say that I am impressed by your vocabulary and your ability to post a coherent question.
Secondly I have to remark upon your restraint in asking for help as this is only your third posting since you joined in 2019.

7 Years in Brewing and materials scientist, so I tend to be fairly resourceful on my own. I'd make more contributions on the forum, but honestly the community here is so quick and knowledgeable its hard to make an impact without looking like a parrot. Thanks for the accolades, though.

Answer: YIKES! That is some serious crud.

I assume I am seeing brush marks that indicate it can be dislodged. Usually white residue is a mineral thing, and, unfortunately, vinegar is a go-to for that.

Correct, those are from my nylon "L-Brush". That gives me hope that this is not a lost cause, but I remain heavily mystified without any industry grade diagnostic devices

What did you have in that when it showed up? From the pictures it looks like it came down from around where the bung would have been. Was there something in there that had a very aggressive fermentation and a strange make up?

The last brews I can recall that would have been suspicious would have been a heff (no frills. Pilsner and wheat grain bill with WLP300) or a low att (WY1318) strawberry ale for a friend's bachelorette party. Strawberry was admittedly artificial flavor

The thing I find strangest is that rimline at the top sits FAR above the bung, and I've let the solutions sit in both the upside down and right side up positions while bunged. Though the idea of stripped rubber from the bung is an intriguing theory.

 

[BDough]

I've seen etching in a glass carboy (from dried Oxi or PBW) that simply can't be removed. But not in that kind of drip-from-the-rim pattern. Gotta be a story there. Some odd cap/plug/bung that releases, er, something nasty.

Are you saying that more has appeared as you've tried to clean it?

Correct, it seems the more attempts I've made at removal, the more the residue diffuses along the glass. Does not appear to necessarily be a multiplication of material, but perhaps a spreading of existing material into a more dilute film. I'm finding the idea of stripped rubber from a bung/cap highly probable, so I thank you for the suggestion.

 

[hotbeer]

It's up on the part of your carboy that is very hard to get too even with a bent brush. And it does look like there are some brush marks in it. If it's actually soft, then put some ice cubes in it and some salt. Turn it over and swirl it around.

If you know you haven't put anything else in it that might be toxic, then I wouldn't worry too much about it.

 

[BDough]

Have you tried attaching one of the bendable nylon brushes to a drill? Wetting the brushes or filling the carboy with any of the above and spinning?

How much time did you give said solutions? I'm not sure about mineral, but I've found a bleach solution, filling them, and leaving in the sun for a day or two works wonders for alot of things. Plenty of rinsing etc.. afterwards.

Have not tried with a drill, but you can see some uh.... trivial success of brush marks of my nylon brush taking out a little bit of the residue. I gave every one of those solutions except the CLR 2 days + in the FL heat of to attempt to cut through the film, but to no avail. I only just tried CLR thinking it would not require significant time to demonstrate a notable effect, but as I had said, it seemed to only make the situation worse.

 

[BDough]

It's up on the part of your carboy that is very hard to get too even with a bent brush. And it does look like there are some brush marks in it. If it's actually soft, then put some ice cubes in it and some salt. Turn it over and swirl it around.

If you know you haven't put anything else in it that might be toxic, then I wouldn't worry too much about it.

Ah for an abrasive clean. Not a bad idea. Will update with any results.

 

[Homebrew Harry]

I'd try soft scrub with bleach. I might even cram a piece of 3M scrubbie in there too.

 

[kmmuellr]

OxiClean / Sodium Percarbonate?

I typically give mine a 140 degree soak w/ Sodium Percarbonate and that does the trick. Good luck!

K

 

[rushpapers]

Try muriatic acid.

You can find it at masonry supply houses and sometimes at chain hardware stores.

It appears to be calcium, like a hard water stain.

CLR is similar, but more expensive. I see you used it, but maybe not enough, and not long enough.