To Reconstitute powdered milk to fresh milk click here.
Sour Milk: To sour reconstituted milk, just add a little vinegar to it, and stir it up. For instance, if a recipe calls for 1-cup of sour milk or buttermilk, then measure a tablespoon of vinegar into a measuring cup. Add reconstituted milk to reach the 1-cup mark. Stir the milk gently. In a moment or two, it will sour. This can replace soured milk or buttermilk in baking recipes.
Buttermilk: To make your own buttermilk, you have to start off with 1/2-cup of fresh, store-bought buttermilk and a quart (4-cups) of reconsitituted milk. Combine the fresh buttermilk and reconstituted milk in a pitcher or jar. Mix it really well. Allow it to stand at room temperature overnight, or for about 8 hours. The milk will have thickened up and cultured into regular buttermilk. Refrigerate or chill and use anywhere fresh buttermilk is called for.
Evaporated Milk: To make evaporated skim milk you only need dry milk powder and water. Measure 1-1/3 cups water into a jar or bowl. Add 1 cup of instant dry milk powder. Stir or shake to combine. This is the equivalent of a 12-ounce can of evaporated skim milk. To make evaporated whole milk, you will need to add some fat to replace the milk fat in whole milk. Do this by preparing evaporated skim milk and then adding 2-tablespoons of vegetable oil to the milk. Stir it up vigorously to emulsify the fat with the milk. It will separate on standing, so mix it really well right before using it. This is best used in cooking and baking. A spritz of nonstick spray will help the emulsification process.
Sweetened Condensed Milk: On the stove, bring to a boil 1/2-cup of water, 1-cup of sugar and 3-tablespoons of margarine or shortening (butter flavored shortening is good). Add a dash of salt. Stir the mixture every now and then. When it comes to a full rolling boil, remove it from the heat. Allow it to cool slightly. Add a cup of instant dry milk powder. Use a whisk to stir it smooth. A fork or a spoon will not get the mixture smooth, you really need a whisk, or egg beaters. There, you are done. This is the equivalent of a can of sweetened condensed milk. This will keep unrefrigerated for a day or two because of the sugar. I have never kept it longer than that without refrigeration. In the fridge it will keep for 2 weeks. For longer storage than that, I freeze it.
Quick Whipped Topping: This recipe is best made if you have electricity. Put 1/2-cup of water into a large bowl and place it in your freezer. When it has ice crystals forming around the edges, remove it from the freezer. Add 1/2-cup instant dry milk powder. Whip the mixture with electric beaters until it is light and fluffy. This will take a couple of minutes. Add 2-tablespoons sugar, 1-teaspoon of lemon juice, and 1/2-teaspoon of vanilla. Beat until thick enough to spoon like whipped topping. Use immediately.