Learned the hard way: Stale water in my kettle breeds more than just bad taste
I've been using the same kettle for my pour-overs for months (you know how it is, busy mornings and all), and I got lazy about emptying it after each use. Last Tuesday, I poured water for my brew and noticed a faint, off smell. When I looked inside, there was a thin, white layer stuck to the bottom. I realized it was limescale and maybe bacteria from sitting water. I fixed it by boiling a mix of vinegar and water, then scrubbing it out. Now, I always dump the leftover water and let it air dry. If you use a kettle, don't skip this step, or you might end up with more than just weak coffee.