How do I index a custom added field?
I think this is the expected behavior: Content is marked to index when you update it, and the next cron run will reindex your items.

You need to enable the checkbox "Index items immediately" for this to be a immediate operation. Be aware this is a costly operation.



If your field type is custom, you might need to expose the value you want to entity API. Check out how to do this in Describe field properties to make custom fields work with Entity Metadata Wrappers.