Today, at noon, we tested the results of the Low Temperature Oven.
The meat, a 6.1 pound Top Round piece of beef, has cooked for 2.5 days (60 hours). It started at a temp of 200 dF for 3 hours. then switched to a setpoint of 140 dF. Because of a high deadband (134 - 146) due to the 'dusk-to-dawn' (DTD)limitations, I later lowered the setpoint to 137 (131 - 143).
We just had lunch with the meat.
The meat was cooked to a perfect medium rare. The meat itself was tender, but most of the gristle had not been converted.
The meat was not overcooked anywhere. There was at most 1 Tbsp of fat drippings in the pan. As noted previously, this is a very, very lean cut of meat. It therefore did not have any fat to carry flavor, which resulted in the meat being bland.
The test itself is a successful test of the concept and the equipment. Because it was a test, we used the cheapest cut of meat we could find, a tough, very lean piece of Top Round. It is not a cut of meat I ever intend to use again by itself. It may make good Philly Steaks, and/or sandwiches. We intend to cut thin slices and make sandwiches with some of the remaining meat.
Will conduct a later test, I intend to use a better cut of meat with more fat in it, cook it at a higher temperature (this was a little too rare for our likes), (I'll try 145) but not for a longer time.
Because this is a oven with no air circulation going on, it does not transfer heat to the meat as fast as a Sous Vide water immersion bath does, so it takes considerably longer to tenderize the meat. This same cut of meat cooked in our Sous Vide cooker would have been fork tender, and all of the gristle would have been converted.
The crust on this was too dried out. It was just tough, not a 'crust'.
So, results: equipment worked great. Bad choice for a meat cut. Temperature a little low for our tastes.