Here’s how you can create a macOS 10.15 beta Catalina beta USB Installer drive for clean installing the OS on your compatible Mac.

So, you’ve decided to use macOS 10.15 beta to its full potential. This means that you are going to perform the ultimate install of the brand new operating system which also happens to be in its pre-release phase. If that’s why you are here, then you need to create a macOS 10.15 Catalina beta USB Installer drive. It takes a little bit of patience, but at the end of the day you’ll have a USB stick at hand will prove itself quite handy in a number of places.

Before you begin the installation, please make sure that your Mac is supported by macOS 10.15. If your Mac is not on the list then there is no point in moving forward at all.First of all, grab hold of a USB flash drive that has at least 16GB of onboard storage. Make sure the drive is USB 3.0 compatible so that everything goes forward at a zippy rate of speed.Download the macOS 10.15 image file and save it to your Applications folder. You can find more details about it by going to this link: Download macOS 10.15 Catalina Beta on Your Mac [How to]Plug in the USB drive to your Mac and launch the Disk Utility application from Launchpad or Spotlight search.You are now going to erase your USB drive and format it properly. Set the name of the drive to its default which is ‘Untitled,’ set the Format of the drive to Mac OS Extended (Journaled), if it is set to APFS by default then let it be. Last but not the least, leave the Scheme to GUID Partition Map.Click on Erase.Assuming that your macOS 10.15 image file is in the Applications folder, launch Terminal and type in the following command exactly how it is shown below:

sudo /Applications/Install\ macOS\ 10.15\ Beta.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install\ macOS\ 10.15\ Beta.app

Hit the Return key on your keyboard and you will then be asked to enter your Mac’s password. Enter your password and hit the Return key once more.

The USB Installer creation process will now commence and it may take quite a while so be absolutely patient during the entire thing. I will suggest not doing anything else on your Mac while the wheels are in motion. Terminal will prompt you when the creation is complete after which you can remove your drive and store it, or keep it plugged in if you are going to perform a clean installation of macOS 10.15 right away.

Want to go back to macOS Mojave? Follow the guide posted below:

How to Downgrade macOS 10.15 Catalina to macOS Mojave [Tutorial]