@buckhorncliffs: Sodium Carbonate (not bicarbonate) It has an indefinite shelf life and it’s an important ingredient in our shelf-stable laundry cleaning formula. Mix 2 tablespoons in a quart of hot water for a powerful cleaner spray. Food-grade sodium carbonate can even substitute for lye in making pretzels. And you can make it yourself by baking regular baking soda for an hour at 300°F. Don’t keep it in the box. Store it in HDPE or glass, in a cool, dry place, and it’ll be ready whenever you need it.