Well I think I have found an answer and dropping it to 200. It doesn't have to be done when I get home if I need to leave it in longer. Everything went in hot.

I was actually just reading about this in an old Cooks Illustrated magazine this morning. They said for the most tender beef roast, it's best to roast at 130 degrees for 24 hours or something like that - but they realize that most people aren't going to do that, so they tried to find alternatives. Their recipe settled on 225 degrees and they didn't bake for more than a couple of hours. I think 200 degrees will probably be fine. Or if your oven goes lower, I would probably shoot for something between the 130 and 200.

Thank you Bluebell. I don't remember what the lowest my oven goes to but I will check.

You want to keep the temp above 160 for sure....to be safe! I would say 200 is great....under the boil...but hot enough to not grow stuff in the parts that are not cooked yet.
It will be wonderful!

My oven goes to 170F, so it's always in the "safe" zone, I guess. If I were going to cook the roast for 7 hours, I'd still go for 225F, probably. I'm assuming it's covered and being braised, not roasted? And it also depends on how large the "large" roast is. 5 lbs? 7 lbs? Bigger? Smaller? It depends on the roast, of course, but I figure about half an hour per pound at 350, so if you have a 10 pound roast, that's going to be 5 hours at 350F, and longer at lower temperatures.

So my answer is......depends on the size of the roast!

Annie

If your oven has a delay start/stop timer on it, use that and do your normal thing. Since the oven will not be opened until you get home, the heat will stay in and it will stay safe.

The roast is perfect as always but it's hard to go wrong with a nice chuck roast.

Fully done at 4:30 when I got home, so 6.5 hours at 225. Thanks everyone!

I'm glad it came out well, bumblebeez. You're right, it's hard to go wrong with a chuck roast if you're cooking it for a long time. I've had them get stringy, but they were still pretty good!

Annie

I have had them stringy too although it has been many years. I've stuck with the same method of cooking it for so long that even a slight deviation made me concerned it wouldn't be perfect.

Bumble, what shape was your roast and did it have a bone? Can you slice it or do you cut it in chunks to serve? My grandmother made the most delicious roasts in cast iron in the oven, but I never knew how she did it. Thanks.

Sheesh, this is a chuck roast which is thick and flat and has great marbling, I never serve it the day I make it but separate the liquid from the meat and the next day, slice the roast, although it will still fall apart some, and degrease the liquid. I package mine up in containers for the freezer too.

Thank you. I have one in the freezer, about 6.5 lbs, will make it soon. It is a 7-bone.