How to set default PyCharm interpreter?

My PyCharm installation has two interpreters available:

• Python 3.3.2 (/usr/bin/python3.3m)
• Python 2.7.5 (/usr/bin/python2.7)

Whenever I open a new project it sets the interpreter to Python 3. Since I work mostly with 2.7, this means in most cases I have to reconfigure it. How do I change it to use 2.7 by default for new projects?

Update: After setting the default interpreter to Python 2.7.5 in File → Default Settings → Project Interpreter and removing the .idea/misc.xml file, the interpreter is now not set at all in misc.xml. Better than setting it to Python 3.3, but still...

File | Default Settings | Project Interpreter.

This configuration sets the default interpreter for the new projects, note the Default Settings menu, it's not the same as File | Settings which sets options for the current project.

If there is no open project, you can access this menu from the Welcome Screen (Configure | Settings).

Please note that it affects Open Directory option. Once you open a directory with your files, a new project will be created with the default interpreter that you have configured using the above steps. New Project option will show you the list of configured interpreters in default order and you will have to choose which one to use. There is a related request to suggest the most frequently used interpreter first.

This has now changed in the newer versions of PyCharm (I've got 2018.2). It's now called Preferences for New Projects: