How to make kidney beans tender

I have done a lot of cooking with beans and I will usually soak them overnight and then slow cook them for an additional 5-7 hours. If I forget to soak them, I will usually have to put them on the stove and boil them on high heat for almost 2 hours stirring constantly.

As far as Chili goes, I have always preferred a mixture of Red Kidney Beans, Black Beans, And "Great Northern Beans" (white beans)

If you are going to be canning this for long term storage you will need to be pressure canning it, and as that will mean some pretty high heat you'd be better off not cooking you beans too long before canning. I'd add them in a few minutes before the end of cooking just to get them warmed up in preparation for canning it as a half hour of cooking plus pressure canning would probably mean mush.