Agreed titanium step bit is the way to go. Made short work of my kegels. Like tripper said your bit is dull or you've hardened your stainless. Get a new bit cutting fluid and go slow
Yes agreed you can taste without boiling if you use a commercial culture. The only way I wouldn't taste without boiling is if I harvested the lacto from grain
You should soak the cubes in whisky or vodka for at least 24 hours to kill unfriendly organisms maybe this is the root of your problem. Did you do this last time as well