Authentic French baguettes, made from nothing more than flour, water and yeast, have a vanishingly short shelf life. They are fresh and delicious for only about half a day after baking. By day two, they're not even fit for sale as "day-old bread," as muffins and pastries sometimes are. To keep a baguette fresh for more than a day, you have only one real option: the freezer.
Prepare a fresh baguette for freezing as soon as possible after purchase or baking. Let the baguette cool completely. Place it in an airtight freezer bag, squeeze out the extra air and zip it closed. If the baguette is too long to fit into the bag, cut it into pieces.
Store the baguette in the freezer until several hours before you need it.
Remove the frozen baguette from the freezer bag, wrap it in a tea towel and thaw it on the counter for two hours, or until fully thawed.
Heat the thawed baguette in the oven at 200 degrees Fahrenheit for a few minutes to warm it, if desired. Don't leave it in the oven for longer than a few minutes or it will dry out.
Keep a partially eaten baguette fresh for several hours by wrapping the cut end with aluminum foil. Do not leave the cut end uncovered. It will become dry and inedible quickly. Don't store the baguette in a plastic bag or container, as this will make its texture gummy.