So far I've attempted it twice. The first time I cooked legs and thighs at 60C for an hour and a half; the second time I cooked two breasts at 60C for about 45 minutes. Both times the chicken came out really tough, and the muscle was really stringy. I assume this means I didn't cook the chicken long enough, am I correct? If so, how long should I be cooking the chicken, and at what temperature?
EDIT: I meant stringy, not sinewy as I had said previously.
Best Answer
You cooked it at too low a temperature.
Sous vide is intended for meat where you want the protein to remain tender. It shouldn't have any sinews. Think chicken breasts, or the long filet along the spine of a pig. This meat gets nicely cooked at 60-65°C (depends on the animal), and tough and dry above that.
Meat marbled with sinews has to be cooked at a temperature where the sinews (collagen) melt into gelatin. This happens at about 70°C at least, and takes hours. Since the muscle fibres are already toughened at that temperature, there is no reason to hold it low; you can put it at full boil in a normal pot and cook it there, you just have to wait long enough. In theory, you could do it in a sous vide bath too, but you won't get any of the benefits sous vide gives to tender meat.