Once you get the hang of basic sourdough bread, it can be really fun to start branching out and getting creative with flavor. One of the simplest ways to get a different (and some would say 'better'!) flavor from your loaf is to let it rise slowly in the refrigerator overnight.
In baker's lingo, this is called "delayed-fermentation," and that is exactly what you're doing!
When dough is refrigerated, the yeast and bacteria go dormant, but the enzymes that have been breaking down flour starches into sugar keep on trucking. This gives you a much higher percentage of simple sugars in your final dough than you would otherwise. The final loaf will have sweet nutty flavors and the crust will get nicely caramelized.
Right after you shape the loaf, cover it with plastic wrap and put it in your fridge where it won't get bumped or jostled. The next morning, set it out on the counter and let it continue rising. Since it has to come up to room temperature first, it will take longer than normal for the loaf to be ready to bake. Allow for double the time estimated in the recipe for the final rising, and then bake as directed.
Since wild yeast is so hardy and long-lived, this technique works particularly well with sourdough breads. But give it a try with your next loaf of regular bread and you'll definitely notice a difference in your final loaf!
(Image: "Bread is Baked" by Peter Seal, $7.99 via AllPosters.com)
Martha Concrete Lam...

Oh I'm so glad you posted this! I only have one loaf pan so put half the dough in the fridge last night since I wouldn't have time to bake two loaves. Now I'll be able to compare the regular one and the longer rise one!
I love long-rise breads! They were a revelation. I started refrigerating pizza doughs for days, then tried it with rustic loaves too. So delicious!
You do start noticing any off tastes or staleness in your flour, though. Those tastes are masked in yeasty, quick-rise loaves, but in long-rise all you're tasting is the flour.