I just finished cooking beets sous vide along with my potatoes at 194 F.
Came out perfect! I peeled after cooking. So much easier! I cooked 90 minutes, it wasn't incredibly large, I would move to 2 hours if larger. Going to test 1 more time, because at work we have a turbo chef oven, no foil allowed. If this works, we can do beet salad like I have wanted to. I'm very optimistic it will work!