Hi David
David
>The following recipe is one of several recipes I have followed to make my >own bread. But it is the recipe I have used most >often. Keep in mind: I have >neither bread machine nor dough mixer; I use muscle power.
>My problem is that my bread is always {heavier / more dense / less filled with >holes / smaller holed / less tall} than it ought >to be This is especially true of bread I bake on a cookie sheet rather than in a >loaf pan; it spreads rather than rises, but >even my loaf bread rises >inadequately.


You are following the standards of the British Bread baking.Their kind
of breads are supposed to be heavier than American type breads of the
same genre. One major factor is that British flour has slightly lower
gluten content that typical American breadmaking flours.

The recipe looks okay...but the way you are making it maybe what makes
the difference.
First...did you knead the dough until fully developed...? really
smooth? Following the timing is not enough....people have different
physical fitness and the kneading process can affected by that
also...An underdeveloped dough can lead to heavier loaves with lesser
volume.
Did it pass the window pane test?

Is the dough wet appearing...or slack. If that is that way then its you
have to reduce your water content slightly.
A firmer dough is not likely to flatten out during rising.
Did you mold your bread tightly... ? that is a factor that can
influence the bread to flatten during proofing....which is the result
of loose molding.It takes some time to be proficient in bread molding.

>The taste is OK and the crust is chewy (too chewy) but the bread is not as light as professional bread

What is your basis for the so called professional bread..? It is the
one you can buy from nearby supermarket...? or from specialty artisanal
bakeries...?
If you are looking for the former then you will have difficulty in
getting it to rise to the lightness....These folks are using additives
to enhance the bread volume....
Meanwhile artisanal breads are not necessarily light nor
heavy....however it depends upon the kind of bread also.
One way to improve the crumb texture is to add diastatic malt as that
will open up the crumb grain and improve oven spring...the malt can be
in syrup or in powder form..
Another thing that improves volume and symmetry is to increase the salt
by half a teaspoon but first bulk ferment it twice.
Most UK professional bread contains 2 tsp salt per 500 grams of flour.
By then the dough is really stable and can withstand better with
increased rising time which results is bigger loaves.

Ferment one and a half hour then knock it back and let it rise more by
quarter of an hour then divide it let it rest for 15 minutes then mold.

Allow it to rise properly and check by using the indent test before
you bake it.
Push your fingertip into the dough and if it retracts immediately it
needs more rising...
If the indentation slowly springs back....then its right for baking
Try these things and let us see the result