Today I noticed the slanted top of one of my 6.5 gallon glass carboys is significantly dented, as if it is sagging downwards toward the beer.
The altered shape is noticeable enough that I doubt I would have missed it the last time I sanitized the carboy and brewed and poured the beer which is currently in the carboy three weeks ago, but it is possible.
I have no idea how glass can be reshaped without very high temperatures. Has anyone else ever experienced warped carboy glass before? Can the pressures and or temperatures of brewing over weeks somehow contribute to this? Seems doubtful, but I am really very lost for a rationale here and am wondering if anyone out there has any insight whatsoever. Very perplexed :?