I've been heating it up on my gas stove for years. Heard a crack and saw a waterfall of yeast starter wort running down the stove. I'm careful with it and wrap with bubble pack when storing. TG I had no yeast in it. Guess I'll have to buy a larger pot to boil in.
As a data point, I had something similar happen a few years back. I always just blamed my less than careful treatment of the flask though. Interesting to see something similar with yours.
There's an old thread on breaking "Pyrex" flasks here... https://www.beeradvocate.com/community/threads/erlenmeyer-flask-broke-while-heating-wtf.224595/
Have been using that exact flask for years? I wouldn't think it's a weak point perse, as maybe it took a hit in storage at some point, probably on that lower corner, and the stress of heating cracked it. Even real pyrex isn't immune to that sort of thing.
