Wait, don't dump that milk! It may have a slightly sour smell and be expiring tomorrow, but you can still put it to good use by making sour milk jam.
Sour milk jam is made by cooking down the expiring milk with sugar and then adding crème fraîche. The pleasantly sour flavor of the crème fraîche will overcome the potentially unpleasant flavor of the milk to create a dessert topping that is as delicious as it is unusual.
Please note that if your milk was purchased from the grocery store (meaning it was ultra-pasteurized) and is way past the date (use your nose to judge how far gone it is) on the bottle or carton, you should not use it—even for this preparation.
Condensed milk is a combination of milk and sugar. According to Serious Eats, condensed milk is reduced to 60% of its original volume. The texture of condensed milk is thinner than cream but thick enough to coat a spoon. It is syrupy and very sweet, and commonly enjoyed in coffee or drizzled over desserts.
Sour milk jam, on the other hand, is not as sweet as condensed milk. The sour flavor of the crème fraîche complements the caramelized sugars in the milk, but neither the sweetness nor the sourness is overpowering. Sour milk jam is also thicker in texture than condensed milk. After refrigeration, the sour milk jam turns into more of a spreadable consistency, while condensed milk remains thin and pourable.
It is easy to tell dulce de leche and sour milk jam apart by their color alone. Dulce de leche has a deep caramel color and may even be mistaken for caramel itself. This is because dulce de leche is composed of milk and sugar cooked down slowly until the sugars are completely caramelized. The texture of dulce de leche is thick and gooey, so it makes a great topping for rich and creamy desserts like ice cream.
Sour milk jam is white because it has very little caramelized sugar. Sour milk jam may thicken slightly in the fridge, but it never becomes sticky nor gooey. It is also much more mellow in its sweetness than dulce de leche. Sour milk jam adds a light, creamy sweetness atop ice cream, but it also pairs well with a simple cup of fruit.
In a medium saucepan over medium high heat, stir the milk and sugar together until the sugar is dissolved.
Turn the stove down to low. Cook the milk and sugar mixture down for about 20 to 25 minutes, stirring occasionally. Make sure to keep a close eye on the pot during the first 5 minutes, as the milk may want to boil over. If it starts to do so, remove the pot from the heat and stir until the milk sinks back down. Then, continue cooking.
The milk will start to thicken in stages. Don't be alarmed when small clumps form; just keep cooking and stirring. Eventually, the milk will thicken into a paste-like consistency. It should reduce to about one-quarter of the volume of milk you started with.
Transfer the cooked milk mixture into a medium bowl. Let it rest until cooled to room temperature.
Whisk in the crème fraîche until the sour milk jam is smooth. There should be no noticeable clumps.
Sour milk jam pairs excellently with cake, stone fruits like peaches or plums, toast with jelly, and ice cream. It is sweet enough to only need a little but light enough that you will still feel good after eating it.
Sour milk jam should be refrigerated in a sealed container, such as a mason jar or Tupperware. It should be used within two weeks of making it.
Cows worked hard to produce that milk in your fridge, so make the most of it by turning your old milk into sour milk jam. Christine Muhlke from Bon Appétit even makes use of her unfinished, expired half and half to make sour milk jam. You're only 30 minutes and a cup of crème fraîche away from one of the best dessert toppings you'll ever have.