Different breads have a different shelf life. A rule of thumb being that the longer the fermentation, the longer the shelf life. Ciabattas, for instance, are good for at least 2 days and our sourdoughs for 3 to 4. This is staling. Spoilage (fungal growth) is a different matter.
The best way to preserve your bread is to freeze it.
To avoid both staling and spoilage you should freeze your breads. To defrost the sourdoughs, let them sit at room temperature until completely defrosted. This might take 4 hours or more depending on the efficacy of your freezer. If using in one go, reheat gently in the oven (5 minutes at 140C).
For the other breads (ciabatta, potato and rosemary and baguettes), defrost and then crisp up in a hot oven (200C). Arguably the ciabatta are at their best under this process
Reheating a loaf is a once off trick. They tend to dry out if the process is repeated.
Written by Adam Robinson of Glenwood Bakery