What is the Shelf-Life of Alginate?
Stored correctly, alginate will last a long time. The main things that cause alginate to degrade are moisture and heat. Our recommendation is to store your alginate at room temperature in a tightly sealed bag. Under these conditions, alginate will still be perfectly usable for 3 to 4 years.
If you forget to close the bag, the alginate will absorb moisture directly from the air and it will be unusable in a few weeks (depending on the humidity level). If you choose to store your alginate in a very hot room, it will also degrade the alginate quickly.
What you will notice, as your alginate begins to deteriorate is a longer setting time and a weaker "gel strength" when set. Our second recommendation is, "When in doubt, buy some more alginate".
If you choose to store your alginate in a refrigerator, it will probably last 10 years or more. Just be sure to let the bag warm to room temperature before opening it. If you don't the cool alginate will absorb moisture from the air very quickly due to condensation (not good).
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