This question is a good-ass question. First of all, NEVER put super-hot glass on something cold. When glass gets hot as shit (in an oven, in a microwave, or on a stovetop, etc.), it undergoes thermal expansion. When it gets cold, it contracts. Ovenproof glassware is meant to be resistant to expansion, but it’s not totally immune to the laws of physics.
If your kettle was hot enough to have boiled off all the water, it must have been pretty fucking hot (thermal expansion can be enough to shatter glass, so it’s a minor miracle that you didn’t have that problem on your hands). When you poured cold water on it, you created a new problem: uneven temperature. Parts of your kettle had reached close to maximum expansion, and now you were forcing whatever parts were in contact with the cold water to contract. Cold water would normally cause contraction, but the speed of contraction (and stress on the glass) was compounded by the drastic change in temperature, from hot as shit to cold as fuck. Furthermore, the coldness was unevenly distributed (limited to where cold water was in contact with the kettle), so some parts of the kettle were expanding while others were contracting. That’s how shit shatters.
In the future, you might try:
- Using a steel kettle, though you can still damage steel by taking it from hot to cold. Steel typically warps, which is better than shattering.
- Letting your hot shit cool down on its own before you expose it to cold shit. Probably best, when removing a glass kettle from heat, to put it on a a wooden (not metal) trivet, so the contrast in temperatures is minimized.
- Not ignoring some shit that is cooking on your stovetop while you watch Golden Girls re-runs.
Yeah, bro. You’re lucky that all your shit is still intact.
Also, a disclaimer: I don’t really know shit about this. If you follow my advice and get glass in your ball-sack, I’m not going to court for it.