Demo page for a fictional bakery (Kornblume, erfunden). Not a real business.
Short answer: store sourdough at room temperature in a paper bag for three to four days, and freeze sliced bread for up to three months. Do not use the fridge.
A sourdough loaf stays fresh for three to four days at room temperature in a paper bag or cloth. The natural acids slow mold growth, so it keeps longer than yeast bread. Slice and freeze what you will not eat within four days.
No. The fridge dries bread out and makes the crumb go stale faster than a kitchen counter does. Keep the loaf cut side down on a board or in a bread box, and use the freezer for anything beyond four days.
Yes. Slice the loaf first, wrap it airtight and freeze it for up to three months. Toast slices straight from the freezer, or thaw a whole loaf on the counter for two hours and refresh it for ten minutes in a hot oven.
Storage times are rules of thumb from the sources above.