If you haven’t tried cooking beef at low temperatures, you should.
Calpains denature at about 40°C/105°F and cathepsins at about 50°C/122°F. Slow cooking for extended periods below these temperatures gets the enzymes working breaking down the muscle tissue to give tender meat.
At about 50°C/122°F (“rare”) the protein myosin begins to coagulate, which solidifies the meat and forces moisture out.
At about 60°C/140°F (“medium”), collagen shrinks and the meat gets firmer and more moisture is pushed out.
At about 70°C/160°F (“well done”), the collagen begins to dissolve into gelatine. It takes a while for all the collagen to dissolve at this temperature (and up to 82°C/180°F), but eventually it will result in drier and tougher meat.
By cooking beef below 50°C/122°F for an extended period of time, it’s possible to achieve excellent flavour and tenderness. (Cook only the outside of the meat to kill of bacteria before doing this – a blow torch is best.)
The rib eye below did go a little over 50°C/122°F, but it took a while to get there. Many home ovens can’t maintain these low temperatures – a water bath is a better option. Paired with some onion relish below, it was still moist, with a tender texture and good flavour.