Time and temperature for converting collagen to gelatin in chuck roast cooked sous vide?
This depends on the end result you are looking for.  At some point, if you leave it in the bath too long, the texture will probably go too mushy for most peoples' liking, but here are a few observations: Baldwin states that 131F (55C) is the lowest temperature for collagen conversion, and that at higher temperatures the denaturing happens more quickly.  So, you could increase the temperature. Since you cooked at 55C, you probably want it on the pink side.  You could go as high as 57C or 58C (though now we are getting into "medium" territory) and still have pink meat. Chefsteps has a recipe for chuck roast, and provides a time and temperature guide.  They cook for 18 hours with temperatures ranging (depending on your desired outcome) from 54 - 72C (129-162F). I am guessing that 18-24 hours produces something that resembles a more traditional roast in the end.  If you are looking for a softer texture, I would go slightly higher on the temperature, and longer on the cook, maybe even 48 hours.