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.