That's hot break: https://www.homebrewtalk.com/f163/hot-break-causing-off-flavors-149820/index2.html
It looks like egg drop soup, and will settle out in the fermenter.
You can filter it between the kettle and fermenter with a hopback, you can let it settle once chilled for 20-30 min. and leave it behind, or you can just let it settle in the fermenter.
It is allegedly preferable not to have too much of it in the fermenter, but I have no negative experiences, I try to leave it in the kettle.
So you siphon from kettle to primary then?
What are some good options to keep it out of the bottling bucket?