Written by Joe AimonettiSome users have reported that occasionally Safari will automatically delete all cookies when the user quits the browser. Upon reopening Safari, no cookies remain.
Cookies are small pieces of text stored in your browser that identify information about your history with regards to the sites you have visited, including site preferences and settings. When these cookies are deleted the user is required to re-enter all of their information--an annoying task for even moderately heavy Internet users.
If you find that Safari is automatically deleting your cookies, you can most likely suspect the cookie preference file has been corrupted. To test this:
1. Navigate to: MacintoshHD > Users > username > Library > Cookies
2. Move the "Cookies.plist" file to your Desktop.
3. Open Safari, navigate to a couple popular sites.
4. Close and Reopen Safari. Check your cookies (Safari Preferences > Security > Show Cookies).