Any idea how long it will take a 4-lb. beef tenderloin to slow roast to med. rare at 225 F. degrees? I'm aiming for internal temp of 125-130 F.
At 275 it would take about 1 1/4 hour to reach 125-130. So I would start testing at that point and every 15 after. I assume at your lower temp that it could take another 30 min.