New Delhi, Dec. 18 -- Cleaning a coffee maker is one of those things we all quietly skip. Not because we don't know better, but because it feels optional. You rinse the cup, toss the used grounds, and move on. Surely that's enough. After all, boiling water runs through the machine every single morning. Steam, heat, strong coffee, what could possibly survive in there?Turns out, quite a lot.Research has shown that the inside of coffee machines, especially the water tank and hidden pipes, can collect yeast, mould, and bacteria over time. These are places you never see and rarely think about. Add daily water use to the mix, and mineral deposits start forming too. The result? A machine that heats more slowly, brews unevenly, and slowly messes ...