Is there a way to list all the crawled properties associated with a specific search result?
I know a particular item was crawled. It is listed in the crawl log. Before mapping managed properties, before doing anything else, is there any way to know which crawled properties are associated with that item? Is there a way through the UI, PowerShell or api? This is an on-prem instance
If I read your question exactly, you want the available crawled properties for a search result. I don't think you can, but you can get the Managed Properties. Mikael wrote up the technique and it still works on perm and there is a workaround in the cloud: http://techmikael.blogspot.no/2014/03/debugging-managed-properties-using.html
Essentially there is a property that contains all properties: managedproperties(filter=600/0/*) that you can return in your search result.
The SharePoint 2013 Search Query Tool on CodePlex is great for exactly this purpose. Be sure to turn on the Experimental Features. https://sp2013searchtool.codeplex.com/
You can use Caml Query Builder. Connect to that list using that tool and fire a query. You will get list items, in header you will see column names for example: ows_Title. This ows_Title(and other column names listed as headers) will become crawled property after full crawl.
