Would a chuck roast shoved into a mason jar then sealed break in the oven if set at only 275 ?

Most likely. The boiling point of water is 212 F... some pressure raises that point... but a mason jar is glass and isn't rated for much pressure before it shatters.

would a chuck roast shoved into a mason jar then sealed break in the oven if set at only 275 ?Hello mark:

Of course it would.

But, if you want the same effect, you vacuum seal the roast, and put it in water set at the temp you want the food to be. That's called sous vide and it's the coolest new way to cook food.

excon

Hello mark:

Of course it would.

But, if you want the same effect, you vacuum seal the roast, and put it in water set at the temp you want the food to be. That's called sous vide and it's the coolest new way to cook food.

exconBut... sous vide isn't done in glass jars... thats done in vacuum sealed plastic bags.