Medium rare has a quite large range when you consider sous vide (129 - 134) because you can select any of them and get a medium rare steak in all cases. When t

Medium rare has a quite large range when you consider sous vide (129 - 134) because you can select any of them and get a medium rare steak in all cases. When testing my sous vide device, I noted that the device is off by one degree. Not sure if that's intentional, but makes sense considering 130F is pasteurization temp, and you'd rather be over than vs under. Since I have kids, I try to stay over 130 - I think I end up dialing it in around 131 F for 1.5 hours (which should be 132-ish, around the middle of the range), and I increase the time depending on the thickness. Fist size filet mignons get 2 hours, and I did a prime rib once for 24 hours. And for your plastic bag question, there exist reusable silicone bags for sous vide. I can't promise you'll be able to do the prime rib in one of those, but for a single steak, most definitely.