How to Make Buttermilk or Sour Cream With Leftover Milk

If your partially-used gallon of milk has just expired (or is about to), try making one of these easy, milk-based grocery staples that won't expire tomorrow. These leftover milk recipes feature two versions of buttermilk, some DIY sour cream, and easy condensed milk. Opt to make any of these ingredients at home to help you save money, waste less food, and give you one less item to pick up at the grocery store.

How to Make DIY Buttermilk

Never run out of buttermilk again by easily making it at home with only two ingredients.

What You Need:

• 1 cup room-temperature milk
• 1 tablespoon distilled white vinegar or lemon juice

Step 1: Combine With Distilled White Vinegar

For every cup of buttermilk your recipe calls for, combine 1 tablespoon of distilled white vinegar or lemon juice with 1 cup of room-temperature milk.

Step 2: Let Sit

Let it sit for about five to 10 minutes as it curdles and thickens.

Step 3: Store in Fridge

Once that's complete, your buttermilk can hold in the refrigerator for up to a week.

How to Make Cultured Buttermilk

If you're looking to make cultured buttermilk instead, the process is a little bit different.

What You Need:

• 4 cups milk
• ½ cup yogurt

Step 1: Heat Milk

Heat milk until it is almost boiling, then cool it.

Step 2: Mix With Yogurt

Combine it with yogurt (make sure it says "live and active cultures" on the label).

Step 3: Store and Let Thicken

Cover with a clean towel and store in a warm, dark area in your kitchen for eight to 12 hours until it has fully thickened.

Step 4: Refrigerate

Keep in the refrigerator for up to two weeks and use it to make fresh scones, sweet potato pancakes, or the best-ever fried chicken batter.

How to Make DIY Condensed Milk

Not only is this recipe a great way to use up milk before it goes bad, but you'll have this perfect-for-baking sweetener on hand for up to six months before it expires.

What You Need:

• 2 cups whole milk
• ⅔ cup of granulated white sugar

Step 1: Combine With Sugar and Heat

Combine milk and sugar in a small saucepan and warm on very low heat until the sugar fully dissolves, occasionally stirring with a spatula.

Step 2: Simmer

Once the sugar and milk are combined, bring the mix to a low, gentle simmer for 30 to 40 minutes and leave untouched. The mixture will darken into a light yellow color, begin to thicken, and reduce by half. If you notice foam accumulating at the edges of your pan, use a spoon to carefully skim off the layer, cleaning off your spoon in between each removal.

Step 3: Cool and Refrigerate

Transfer into a jar to cool. Store in the refrigerator for up to six months. Use your condensed milk to drizzle over fresh strawberries or to sweeten homemade ice cream.

How to Make DIY Sour Cream

What You Need:

• ¼ cup of room-temperature milk
• 2 teaspoons of lemon juice
• 1 cup of heavy cream
  

Step 1: Mix Milk, Lemon Juice, and Heavy Cream

Pour milk and lemon juice into a jar and mix, then add heavy cream.

Step 2: Shake

Close with a lid and give the jar a good shake to combine all of the ingredients.

Step 3: Let Sit Overnight

Remove the lid and cover it with a breathable cloth, like a cheesecloth or paper towel, and leave it on the counter overnight or for up to 24 hours. Your DIY sour cream will be good for two weeks in the fridge and is perfect for adding a dollop to your beef tacos or burrito bowl.