I think the brand matters. My health food store used to grind their own, either raw or roasted...
They used to sell it in small 4 oz. containers, and it wasn't bitter at all.
But one day, they were out, so I had to buy one of those ones you bought, the Joyva one. I was so disappointed, because it was bitter. I threw it out.
I found another brand, in a tall glass jar that was much better. I'm out now, and of course I can't remember the brand, but the next time I go to the health food store, I'll let you know.