nostr:npub1ypfcrd4k5ryzlcg8jmdvgrlk29ladfe27z7c2aaq8lvmks6drwqqautsp5 Yes, you are correct. Here is an article that discusses that you need to remove the tannins. 

WebMD “Are acorns safe to eat?”
https://www.webmd.com/diet/are-acorns-safe-to-eat