build up on carboy

[stadelman]

While cleaning my carboy a couple of fermentations ago, I noticed what appeared to be some sort of a build up toward the top of my carboy. It's white in color and looks kind of like hard water or mineral build up.

I soaked the carboy in oxyclean and tried to scrub it with a carboy brush. It didn't budge. So, I figured it was some sort of permanent mark and moved on.

After the next fermentation I, mistakenly, left the carboy sit with oxyclean in it for a couple of days. I noticed that most of the build up was gone. I tried to scrub the rest out and after a couple more days of soaking all of the build up was gone.

I'm about to rack out of the carboy again and I'm noticing the same build up.

I'd like to be able to clear up this build up without having to let the carboy sit for four days. Do I need to stop being cheap and switch back to PBW?

Is there anything else that can more easily and economically clean this sort of build up?

I was thinking about trying a strong bleach solution.

Thanks for the help!

[DannyW]

hit it with a mild acid like white vinegar or Star san and it should go away.

[stadelman]

I'm using Star San to sanitize and it doesn't touch it. I give vinegar a try.

[seanhagerty]

use a small bit of straight star san. The build up is exactly as you said, similar to a hard water deposit. To remove it you need a weak acid, like starsan or vinegar. Prob with starsan is once you mix it with your water, you dont know where the pH is gonna go. Try straight starsan, or the vinegar, or even the lime away stuff they sell. If you use lime away, make sure you rinse realy really really well.

Sean