Beer tastes tangy/ sharp

Hi
I have just done a 'Make Your Own' homebrew kit with 10 day primary fermentation and 10 days secondary. I have just transferred to a cool dark place but decided to try a half filled bottle as it had already cleared. The taste was OK but was a bit sharp/tangy....my wife said it tasted a bit like beer with pipe cleaner in it! Have I done something wrong or will the taste improve if I leave it for a few more weeks?
Thanks
Chris

What temp did you ferment at?

I have a heating belt and it kept it at about 22-24 degrees centigrade