In a large bowl, mix warm water and yeast . With a wooden spoon, stir in the sugar, salt, sour cream, and canola oil. Add 2 cups of flour and stir until well combined.
Add enough of the remaining 1 cup flour to make a dough that holds together and follow the spoon around the bowl.
Turn dough out onto a lightly floured surface and knead for 10 minutes, adding more flour as needed until the dough is firm and smooth to the touch.
Place dough in a medium greased bowl. Turn dough over in a bowl so that the top is also lightly greased. Cover with clean cloth and let rise in warm, draft-free place for 1 hour.
Punch down dough in the bowl.
Turn dough out onto a lightly floured board and knead for 5 minutes or until the bubbles are out of the bread.
Shape dough into a loaf.
Place the loaf in greased 9 X 5-inch bread pan. Cover and let rise in a warm, draft-free place for 45 minutes or until doubled in size. Meanwhile, position a rack in the center of the oven and heat to 375 F. Brush the loaf with egg white if a glossy crust is desired.
Bake for 45 minutes or until bread is golden brown and sounds hollow when the top is tapped. Remove bread from the pan and let cool on a wire rack before slicing.