It does happen to everyone. We never seem to have butter when we need it.
I think I've encompassed a few that are already here...
Handy Substitutions:
1 cup cake and pastry flour = 1 cup sifted all purpose flour less 2 tablespoons
1 cup buttermilk = 1 cup thinned plain yogurt (thin with milk) = 1 cup milk plus 1 tablespoon vinegar or lemon juice; let stand 10 min and stir
1 cup self rising flour = 1 cup all purpose flour plus 1 teaspoon baking powder and 1/4 teaspoon salt
1 ounce unsweetened chocolate = 3 tablespoons unsweetened cocoa plus 2 1/2 teaspoons butter
1 teaspoon lemon juice = 1/2 teaspoon white vinegar
1 cup milk = 1/2 cup evaporated milk plus 1/2 cup water
1 teaspoon baking powder = 1/4 teaspoon baking soda plus 1/2 teaspoon cream of tartar
1 cup cream cheese = 1 cup cottage cheese plus 1/4 cup butter or margarine
4 cups whole milk = 4 cups skim milk plus 3 Tbsp. cream
1 cup sour cream = 3 tbsp. melted butter plus plain yogurt to 1 cup
Juice of 1 lemon = about 2 tablespoons
Heavy cream = 2 percent evaporated milk
Sour cream = plain low fat yogurt
Mayonnaise = 1 part real mayonnaise blended with 1 part lowfat yogurt
Eggs = two egg whites
Egg yolks to thicken sauces = cornstarch, flour or arrowroot
Oil for sautéing = use stock, wine, juice or vegetable s
