With raw material prices rising (especially cream), dairy processors want to make sure they are using everything they buy. It is painful to watch high-priced inputs literally go down the drain. And to add insult to injury, dairies pay discharge fees to boot.
Product recovery systems (PRS), or pigging systems, are designed to recover valuable product that would otherwise be lost to waste. Blue Bell Creameries uses a pigging system on the chocolate coating line at its plant in Brenham, Texas. The ice cream maker uses four different chocolates (including milk chocolate and dark chocolate) in production of its novelties. At the end of each flavor run, the ice cream processor pigs the line so that the previous flavor (vanilla, for example) does not contaminate the next flavor (dark chocolate).