Homemade whey is needed to produce fermented foods and the authentic old fashioned fizzy drinks. It is healthy and you can have fun with it. Whey can be used in multiple ways as with other cultured milk products. This is the stuff that REAL Kimchee is made with... not vinegar.
Regularly adding beneficial cultures to your diet will aid your digestive tract by providing "good" bacteria. Whey made from fresh raw milk or fresh yogurt - is the best possible method. So use fresh, raw, and organic when ever available. I hope you enjoy the ever so slight sour bite to the finished yogurt product, and to the whey.
Keep everything sterile and cleaned with vinegar water - NO DISH-SOAP!! Rinse with filtered water, not muni-tap because the chlorine will kill your main product rendering it contaminated and useless. Store your whey in a glass [mason] jar. I personally have several methods and various cultures. Piima, and Villi to name a few [Fil Mojlk is my favorite butter-milk]. This recipe here will be the easiest to prepare. The ingredients you can purchase from the local natural foods market. I am brand specific because of the health factor. You need to start with live fresh cultures, and healthy WHOLE RAW if possible milk. Baby it isn't gonna work with highly advertised, flavored, sugared, fancy pansy yogurt and fractionated [homogenized] milk, no no no!!! Please buy the Voskos Greek un-flavored yogurt and Raw whole milk by Organic Pastures, Claravale Farms, or what ever Raw Organic milk you have available in your area. You almost want to hear it MoOOoooOOoo.
My finicky Supplies list:
sauce pot, thermometer capable range around 104 degrees, 1/1/2 quart glass bowl, 1 yard cheese cloth folded to an 18" square, a strainer, wooden spoon, 1 quart wide mouth mason jar or tall glass pitcher, stove/oven/or yogurt maker (my Yogurmet came from a thrift store 8 bucks), and patience... wait for it.... wait for it. ok go!
I don't know if I can value the nutritional calculations here regarding the Whey because I don't think they can calculate Whey separate from Milk. The value they will provide will probably be for the secondary product - the yogurt.