Creative Ways to Use Your Leftover Whey

Ricotta Cheese on wooden board and spoon

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If you've made your own Greek yogurt, labneh, or even other cheese, you're left with a bunch of whey. This thin liquid that's leftover is from the coagulation of proteins and fats in milk and cream during the cheese-making process. Before you pour it down the drain, hold off. Whey is actually pretty useful stuff.

First, determine which kind of whey you're working with. Sweet whey is the whey that comes from things made with rennet, like most cheeses. Acid whey comes from products that have used bacterial action to acidify the food, like goat cheese, yogurt, sour cream, and labneh. As the name implies, acid whey is higher in acid and therefore has different applicability. 

It's also important to note whether you added salt to your dairy before straining. Salt in the whey may limit its use as well. 

Sweet, Unsalted Whey

Try these uses for the sweeter whey:

  • Make ricotta: True ricotta cheese is made from the whey that's left over from making mozzarella and other cheeses. To make ricotta, the whey is heated, often with fresh milk and citric acid added. Then the curds are harvested. 
  • Heat the whey: If you're making mozzarella, you must stretch the curds in hot water. You can use the whey instead of plain water. 
  • Make butter: Left to cool for a few hours or overnight, the cream present in whey will rise to the top and can be used to make butter
  • Pest control: Strain the whey well, and dilute 1:1 with water. Then spray on plants to keep powdery mildew at bay.
  • Amend soil acidity: If you're growing plants that need more acidity, like tomatoes, or if you want to turn your hydrangeas blue, bust out the whey! 

Acid, Unsalted Whey

Use the more acidic whey in these methods:

  • Drink it: No kidding. Whey is full of probiotics and has a bracing acidity. It may not be palatable on its own, but try it in smoothies, or even cocktails. Just be aware that whey does have lactose in it still, so if you're intolerant, steer clear. 
  • Make lacto-fermented soda: A dash of whey can be used to make a refreshing, effervescent beverage. 
  • Kickstart lacto-fermentation: Since acid whey comes from lacto-fermented foods, it's already got a bunch of the good bacteria in it you need to get a good ferment. Add a tablespoon or two to a new ferment to get it bubbling. (Salted can be used as well.)
  • Whey up your beauty regimen: The acidity of whey tones skin, so add it to your bath water or swab on with cotton for dewy skin. 
  • Condition your hair: If you're using an alkaline shampoo (such as the no-poo method), whey acts as a balancer, neutralizing the pH. Even with regular shampoos, rinsing your hair with whey can make it smoother and shinier. 
  • Feed it to animals: This is an age-old practice in Emilia-Romagna. The whey from the production of Parmigiano Reggiano is fed to the pigs that ultimately become prosciutto. Don't have pigs? Add some to your dog's diet, or backyard chickens. 

Salted Whey

The richer saltier whey can be used for the following:

  • Soup stock: Whey adds a deep flavor as a base in soups and stews, much like a stock. 
  • Bake with it: The acidity of whey has a softening effect on glutenous bread and pizza dough. Adjust your salt in the recipe accordingly. 
  • Soak nuts and grains: Why use water when you can soak nuts and grains in whey? It adds flavor and probiotics to the nuts or grains.