Out Of Whole Milk? Just Use Sour Cream Instead
It's hard to think of a more common staple in the refrigerator than a carton of milk. It's such an everyday commodity that its price is often reported in the news as a bellwether of the economy. There are times, however, when you need a little bit of milk for cake or a bowl of pasta, only to find that the container is empty, or even worse, what's left has gone bad. Still, an unexpectedly empty carton of milk shouldn't stop you from making a recipe. As long as you have a container of store-bought or homemade sour cream sour cream, you can substitute it in most recipes that call for milk, even pastries, and it will still come out great.
If you're in the middle of making a batch of mashed potatoes, a loaf of banana bread, or a box of macaroni and cheese, and you're all out of milk, substitute a little sour cream. Not only will you get all the richness and milky flavor you need, but you'll also get a little extra tangy flavor. Most of the time, all you need to do is substitute the sour cream at a one-to-one ratio for the milk.
Savory swaps for sour cream
Milk is essential to many savory dishes like mashed potatoes, creamy sauces, and thickened soups or gravies. There are times when you need the liquid volume of actual milk, like for making grits or corn chowder. However, most of the time, when it comes to savory dishes, milk could just as easily be swapped out with sour cream to get an even more delicious result. In fact, you can substitute sour cream for milk almost anytime the recipe calls for less than a cup of milk.
One of the most common ingredients to use milk with is potatoes. Spuds love dairy, so if a recipe calls for milk, sour cream almost always works in its place. If the recipe isn't super dependent on milk for moisture, as with whipped or mashed potatoes, you can use a one-to-one ratio for making a sour cream substitution. If your recipe needs the water in the milk, that's okay, too. Just whisk a little bit of water into your sour cream to thin it before you use it for something like scalloped potatoes. This is true with most other savory recipes that call for small volumes of milk, including cheese sauces for pasta.
Baking with sour cream
Baked pastries and savory dishes don't follow many of the same rules when it comes to dairy, but that doesn't mean that sour cream isn't just as useful in the mixer as it is in the skillet. The most important thing to remember when you're making substitutions during baking is that you don't want to upset the delicate balance of a recipe's moisture and leaveners like baking soda and powder. Baking is a little bit of a science, and you have to follow the rules if you want your cake or muffins to rise properly.
The good news is that you can swap sour cream into baking recipes like banana bread at the same one-to-one ratio you would use for savory recipes, but you'll also need to make other adjustments. For each cup of sour cream, instead of milk, add an extra teaspoon of baking soda and reduce the baking powder by a teaspoon. Also, if you're using butter or shortening, as with biscuits, you can scale the fat back by ½ a cup for every cup of sour cream, as it has a higher fat content than liquid milk. Once you make the adjustments, stir in your sour cream and make your recipe as usual.