Well, most people like to say "trim it to about 1/4" of fat..."
Me, I leave it all on and just trim off any that doesn't look right (yellowish or dried out, etc).
Until you know your way around a brisket, I wouldn't worry about trimming. You could trim too much in the wrong places.
Don't worry.
Throw it in, fat side up and all the fat will scrape off when it comes out.
When are you cooking?
------------------
Smokin OkieIt's done when it's doneCookshack BBQ Guide Page