The good news: keeping a mug clean takes almost zero effort if you do a few simple things regularly.

Rinse it right after use.
This is the #1 rule. Don't let coffee or tea dry inside. A 5‑second rinse under hot water right after you finish saves you from scrubbing later. Do it every time.

Wash with soap daily.
Even if it looks clean, bacteria can grow in leftover moisture. Use warm water, a drop of dish soap, and a sponge. Pay attention to the inside bottom and the rim — those spots get touched by your mouth and collect oils.

Deep clean when stains show up.
Brown coffee or tea stains are stubborn. Here's a quick fix:

• Sprinkle some baking soda on a damp sponge and scrub — it acts like a gentle abrasive.

• Or fill the mug with hot water and drop in half a denture tablet. Let it fizz for 10 minutes, then rinse. Works like magic.

• For really tough stains, mix equal parts vinegar and water, fill the mug, microwave for 1 minute (if it's microwave‑safe), let it sit for 5, then scrub and rinse.

Don't forget the lid and crevices.
If your mug has a lid, a sipper, or a rubber seal, those are bacteria hotels. Pop them apart regularly and wash separately. A small brush (like a straw cleaner) helps get into tight spots.

Skip harsh bleach or abrasive powders.
They can scratch the surface, making it easier for germs to hide. Stick to baking soda, vinegar, or mild dish soap.

Dry it completely before storing.
Wet mugs left upside down can still trap moisture inside. Turn it upright and let it air dry fully before putting it away. Or wipe with a clean cloth.

When to replace it.
Cracked ceramic? Chipped rim? Scratched plastic? That's where bacteria love to hang out. If you can't get the smell out even after deep cleaning, it's time for a new one.

That's all. A clean mug makes your coffee taste better (seriously) and keeps you from drinking yesterday's stale residue. Five minutes a day — worth it.