How to access render layers? I'm rendering static images in Blender under Windows 10 and I want to have all the render layers available for post-processing, etc.
My problem is that the render layers are available only so long as the .blend file remains open after the render; once I save the .blend file and close Blender, then re-open the same .blend file, the render layers are gone.

Image/Read Render Layers (CtrlR) does not recall them.

Output/Cache Result is enabled, and while I have an cache folder path defined, that folder yet remains empty.

Meanwhile ever since enabling Output/Cache Result my .blend files have grown from a few dozen MBs to half a gig each, so I'm assuming the render layers I'm seeking are buried somewhere in the .blend file, but again: How do I access them?
Render your image to OpenEXR MultiLayer format and save the image after rendering.



When saving the image, ensure you have the composite node connected and not a viewer node connected, or the layers will not write.

Doing this, you can open the image at any time for further post processing or grading by simply adding an image node, and you will have access to all the passes and render layers from the image.