Right after harvest, it is best to clean the snap peas, then when partially dry (not fully dry but not dripping with water either), place them is a paper bag then into the freezer. The paper, will allow them to freeze naturally, you also might want to consider placing a small amount of follage from the snap peas also in the bag, just prior to freezing, and do not nover stuff the bag, give the peas a little room to expand and breath during the process, this will ensure a tasty meal when thawed.