system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does bathroom sink water seem to taste different than kitchen sink water?
gpt
Measure the temperature difference of the first 20 seconds of water. That can make a huge difference to taste. Ground water is often cooler than the extra house piping needed to reach the bathroom.

Aerators often found in bathroom taps to prevent splashing change the taste too (and get gross, they need removing & cleaning). 

Your kitchen faucet probably cost twice as much as the bathroom fitting, and is more likely to use ceramic valves and noble metals that don't impart a bad taste. As the most frequently used faucet it will hold fresher water too.