I just received an old and pretty clean glass carboy from my grandfather who did some brewing some decades past. The only thing problematic is some white stain at the bottom which seems hard to remove. First I tried a mixture of rice, baking soda and water (read that one on another forum). That didn't work so I bought and used some PBW, put about 1 oz of it and filled the 2,5 gallon carboy to the brim. I let it do its magic for 30 minutes then rinsed, but no apparent effect after drying. I have also tried to brush it as well as I could.
I followed the PBW instructions from the site where I bought it. Should I use more or let it sit longer?
Picture below. Thanks for the help!
I followed the PBW instructions from the site where I bought it. Should I use more or let it sit longer?
Picture below. Thanks for the help!