Flac and tags

I added a 11MB cover art to a 23MB FLAC file with Mp3tag, so I got a new 34MB FLAC file.
Then I removed the cover art but the FLAC file size didn't change (it's still 34MB).
Why? And how I can recover the initial file size without re-ripping the file from my CD?
Thank you

Once you removed the cover did you resave the file?

How to decrease the tagsize after deleting coverart

Yes I did...thank you

Thank you...