Step 1

Melt the unsalted butter in a saucepan over low-heat. Place ⅓ cup (75 g) of unsalted butter into a saucepan. Turn the heat up to low, and wait for the butter to melt; you can stir it occasionally with a spoon or rubber spatula.Do not use margarine or salted butter, as the resulting heavy cream won't taste right.

Step 2

Stir 1 tablespoon (15 mL) of the melted butter into the cold milk. This is known as "tempering" and is very important. If you pour all of the melted butter into the milk at once, the milk will heat up too fast and curdle.Whole milk will give you the best results, but you can use 2% milk as well.Do this in a separate container; a large measuring cup would be ideal.You are using the entire 3⁄4 cup (180 mL) of cold milk for this step.

Step 3

Pour the milk into the rest of the butter and cook it over low-heat. Pour the tempered milk into the saucepan containing the rest of the butter. Turn the heat up to low and wait for the milk to heat up, stirring it often with a whisk. Once the milk starts to steam, you are ready for the next step.Do not let the milk come to a boil.

Step 4

Mix the cream until it thickens. A blender will work the best, but you can use a food processor, an electric mixer, or even a hand-held mixer. How long it takes for the cream to thicken depends on which tool you use; expect it to take a few minutes, however.You are looking for a thick, creamy consistency--just like heavy cream.This recipe will not thicken into a whipped cream consistency.

Step 5

Keep the cream in the fridge and use it within 1 week. Allow the mixture to cool to room temperature first, then transfer it into a lidded container and put it into the fridge. You can use this as a substitute for most recipes that call for heavy cream.The cream will separate over time. If that happens, simply give the container a good shake. You can also reheat it over low-heat, then give it a stir.