We had a water incident in the kitchen recently. A large amount of smelly brown water was discovered in the bottom of the cabinet under the sink. Turns out that the sink basket, the part on the underside that holds the strainer, was rotted away.
Sami said it was rusted away but my opinion is that it was chemically eroded. And the chemical was hot coffee.
We have issues around here with residual dish detergent due to inadequate rinsing. Without mentioning any names, one of us in this marriage insists that hand washing is more effective and results in a cleaner dish than using the dishwasher. That's all well and good, but using a vast amount of liquid detergent to work up a good soapy sponge also calls for a thorough rinse, and that's where it all falls apart.
How many mornings did I pour out the first cup into my 32 oz. Turkey Hill insulated cup and be met with a layer of soap bubbles? Very many. And it's not those coffee brewing bubbles, either. It's genuine soap that smells all perfumey. So I dump it out and pour out more from the pot.
I realized long ago that if I pour the soapy coffee onto the bottom of the stainless steel sink, it makes it look dirty and has to be cleaned away. There's only so much wastefulness a person can tolerate before 7am, so to avoid running even more water down the drain, I took to moving aside the strainer basket and pouring the coffee directly down the chute.
So I'm pretty sure - based on my long-time experience of working in dialysis units and rotting out plenty of pipes there by pouring 1:10 dilutions of bleach water into the sinks without rinsing it away - that this is what caused the problem in my own kitchen. Coffee is fairly acidic, is it not? It just takes a longer to wear through metal than bleach does.
I suppose a prudent person would avoid this whole soap bubble/ coffee down the drain thing by careful rinsing of the dishes in the first place, but that's not how we roll around here.
[footnote: And now that I think about it, how safe am I from the perils of drinking soap bubbles in restaurant cappuccino? Friends and acquaintances accept my idiosyncrasy of refusing to drink out of restaurant coffee cups if they are not white. How do I know that the cappuccino cups - white or not - have been thoroughly rinsed under all that milk foam? Now it occurs to me that I have had perfumy cappuccino here and there. This line of thinking needs further development.]