How do I erase a CD-RW or DVD-RW on a Mac using Disk Utility?
Launch Disk Utility. Disk Utility is found under Utilities in the Docks Apple menu. Select your disk from the list of disks and volumes on the left. Click on the Erase tab. Under Volume Format choose Mac OS extended (Journaled). If you want to erase the entire contents of the disk by writing zeros, click Security Options, then select the option you want and click OK. Click Erase.
