Thank you so much for your reply. However I guess I am confuse with part of your comment. You are saying: Cooking at temperatures between 60-70°C is of no value, as collagen has not been enzymatically degraded and will start shrinking at 60°C, squeezing juice out of the meat. Are you assuming that the ultimate tenderness and juice out of a meat is better found in Rare to Medium rare ? or below 60 Celcius Therefore If I understand correctly, all my cheeks should be done in the 55 to 60 range for the best tenderness. Your recommended range from 24 to 72 hours is huge. How to I establish the ideal time? trial and error? Is their some kind of ratio that I can refer to, for example, if I have a 100 gram cheek it should be 30 hours, if it is 150 gram it should be 40 hours etc... Thanks again for your help. I love to experiment but their is not point to try to re invent the wheel if someone already has the knowledge out there. Dan