In a word: No. They are cooked in ovens before canning. These pages
describe the process.
"A known process for canned baked beans includes the preliminary step
of cooking (baking) the beans and sauce in an oven for seven hours in
600 pound batches prior to the canning step. In an effort to shorten
this preliminary step in the process, it has been experimentally
determined that cooking the beans, in sauce, in a retort for 20
minutes at 250.degree. F. will shorten the oven residence time 43%, to
only three hours, but there still remains the disadvantages of loading
and unloading the retort, batch by batch."
United States Patent 4181072
2.5 Baked beans are tinned beans in tomato sauce. They are
particularly popular in the UK, although they are also available in
other countries. The main inputs to the manufacturing of baked beans
are beans (usually navy beans), tomato paste, vinegar, thickeners,
sugar, salt and spices, with steel used for packaging. The
manufacturing process involves making the tomato sauce by mixing and
heating the relevant ingredients; sorting and cooking the beans and
mixing and canning the final product. Baked beans may also have added
to them items such as sausages, chicken nuggets and black pudding."
A report on the completed acquisition of the HP Foods companies by HJ
Heinz Company and HJ Heinz Company Ltd
"Baked beans are processed in tomato sauce or brown sugar and
molasses, usually with pork, and cooked in ovens."
Canned and Frozen Vegatables
Agricultural Marketing Service
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