- The precise answer to the question "How long does powdered sugar last?" depends to a large extent on storage conditions - when properly stored and kept free from contaminants, powdered sugar (also known as confectioners' sugar or icing sugar) has an indefinite shelf life.
To maximize the shelf life of powdered sugar, store in a cool dry area and keep tightly sealed after opening.
How long does powdered sugar last at room temperature? When properly stored and kept free from contaminants, powdered sugar has an indefinite shelf life.
To prevent powdered sugar from hardening once opened, place sugar in a covered airtight container or cover original package with a heavy-duty plastic bag and seal.
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