I've done a search here and on google but I'm still not getting how cooking with sous vide is safe. Specifically getting the food out of the danger zone in ample time. I can see if it's a thinner cut of meat, but what about something like a roast or butt? I see where people cook them for like 8-16 hours at temps of 140-150. How does a larger cut hit that internal temperature in time to be safe?