A lighter loaf is generally attained by a combination of the kneading process which stretches the gluten and a slow first prove. Its best not to try and rush the proving process by setting the the dough in a place that is too hot. What you want to achieve is small bubbles of gas resulting from the fermentation process. Lots of small bubbles good! Once you have knocked back the dough after the first prove don't get into heavy kneading again. Knock back, cut the batch into appropriate weights for the tin size being used, fold the dough like a Swiss Roll, place it in the tin with 'seam at the bottom, press the dough gently at the sides so that the centre is raised and set for the second prove - again don't rush the process.
Try to ensure that the second prove when the dough is in the tin takes the mix above the lip of the tin. The trick is to catch it just as it reaches its max - it will be like a slightly wobbly jelly.
I always cover proving dough with a damp tea towel.
Try using milk rather than water or a half milk half water mix.
The other 'trick' for improving 'heavy' loaf if you are not getting what you want by the normal method is to put the bread into a rising oven rather than starting hot and reducing the temperature. The latter bakes the outside and does not let the interior expand, moisture gets trapped - hence the denser texture. Switch the oven on, leave for a few minutes then set to the final baking temperature and set the bread tins on the middle shelf.
I started baking my own bread more than 30 years ago when a Jewish baker in Edinburgh's Southside closed - they made Rye bread to die for. I find that its better to bake a batch of small loaves - keeps oven costs down - and freeze them or do bread and a decent batch of morning rolls. Adding a little oil or butter to the mix also helps them keep when frozen.
The Roux Brothers published an excellent book on bread, rolls, croissants and pastry. It is probably now out of print but worth asking your library if they can get it on loan for you. Nowadays you can scan the pages that you want to keep.
Persevere, its a bit like brewing good beer, once you have cracked the methodology its as easy as falling of a log.
