The minimum percentages of crude protein and lactose and the maximum percent of ash must be declared on the label for WPC due to product variability in these respects. The liquid raw whey must be of good quality, and not too acid or over neutralized. Care must exist during the filtration process, and especially during the drying process as whey proteins are very sensitive to heat damage and denaturation. A brownish color and off flavors can develop and solubility is reduced. White to off white.
Solubility is more important than screen test.
Availability is generally linked to whey supplies and prices. Extensively used in milk replacers, early weaning pig feeds, pet foods and other specialty feeds.