Is chrome incognito mode cache stored on the disk or in the ram, and is it encrypted?
Chrome does store most of the data in the virtual memory (RAM) and therefore not stored on your disk BUT not all off the data is stored in RAM, some such as SESSIONS are stored in exactly the same place as if not in Incognito.You can open the Resource Monitor tool within Chrome, go to disk, sort the image column under the disk activity section, then open and incognito session and go to any website. You should see a few lines of your harddrive writing data to ...\chrome\user data\default\ even in incognito mode.
You can find out more about this here: https://www.magnetforensics.com/computer-forensics/how-does-chromes-incognito-mode-affect-digital-forensics/
Also if your interested in how incognito works and other steps you should take to stay anonymous online, take a look at this:
Hope I could help.