A year's supply of dry yeast, baking powder, and baking soda are essential in preparing baked foods. At high altitudes, less leavening is needed. Below is a recipe that can help you extend your yeast supply.

Everlasting Yeast

1 qt. warm potato water (Strain excess water after boiling potatoes; refrigerate water in air-tight container.)
½ yeast cake or ½ tbsp. dry yeast
1 tsp. salt
2 tbsp. sugar
2 cups white or whole wheat flour

Stir all ingredients together. Place mixture in a warm place to rise until you are ready to use it for baking. Leave 1 cup of everlasting yeast for a start for next time. Between uses, keep leftovers in a covered jar in the refrigerator until a few hours before you are ready to use them again.

For the next baking, add the same ingredients, except yeast, to the everlasting yeast start. By saving some of the everlasting yeast each time you use it, you can keep yeast on hand indefinitely.