To freeze the cooked barbacoa beef I shred the meat and let it cook down to nearly room temperature. Then I place the meat into either 1 gallon sized freezer bag or several quart sized freezer bags. Press the excess air out of the bags before sealing and lay them flat. I then write on the bags with a permanent marker the contents of the bag and the date and tuck them away in my freezer. The meat is best used up within about 6 months.