Need help to make my bread fluffy
I've only recently started baking bread, and was given the following instructions/recipe:
4 cups warm water + 8 Tbs sugar + 3 Tbs yeast <- let rise for ~ 20 - 25 minutes
4 cups white flour + 2 cups wheat flour + 2 tsp salt + 1 cup sugar + 1/2 cup melted butter
Let this "sponge" rise for ~ 30 min
knead in ~ 4 - 5 cups flour (1/2 white, 1/2 wheat) - knead for ~ 30 minutes
Let rise for ~ 1 hour
take dough out of bowl, knead for ~ 20 - 30 minutes, then cut into two equal pieces, place into pans, and let rise for ~ 1 1/2 hours
Bake at ~ 160 C for 45 minutes
My problems: 1) When the dough rises, it gets to the top of the pan and just pours out over the sides - it doesn't rise "up" 2) When it's baked, it's dense and heavy (I want it to be light and fluffy) 3) The bread gets super crumbly after it's cooled <- I recently made one that was less crumbly, but still not how I want it.
Can anyone help me here?