This dough can be purchased fresh or frozen in 14 x 18 inch sheets, which must be handled carefully to avoid tearing. It is best not to thaw the sheets at room temperature since they easily stick together and become difficult to separate. Instead, defrost phyllo overnight in the refrigerator. Due to the thin consistency of this product, it dries out quickly, becoming brittle if not kept moist or if allowed to be exposed to air for long periods of time. Therefore, phyllo dough being prepared for use at room temperature should be kept moist by laying a damp towel over the sheets after they are removed from the refrigerator. Then, when working with the dough, make sure the prepartion is accomplished quickly, keeping the dough workable and not too dry which will hamper working with the dough. Each sheet being prepared can be brushed with olive oil, cooking oil or melted butter in order to keep the sheets from becoming brittle as they bake.
Phyllo dough can be stored for 2 to 3 weeks if it has not been exposed to air or only a few days if the package containing the dough has been opened. It can also be frozen and kept for approximately 4 to 6 months for best results. However, once thawed it should not be refrozen or it becomes brittle and difficult to use.