Alkylene oxide capped secondary alcohol ethoxylates as fermentation foam control agents

A foam control agent of formula I:

• wherein R1 and R2 are each independently hydrogen or a linear or branched alkyl group containing from 1 to about 18 carbon atoms, provided that R1 and R2 together contain from about 8 to about 18 carbon atoms, and further provided that less than about 10 mole percent of R1 or R2 is hydrogen;
• R3 and R4 are each independently hydrogen or an alkyl radical containing from 2 to about 6 carbon atoms, provided that R3 and R4 together contain from 2 to about 6 carbon atoms;
• n is an average value ranging from about 3 to about 40;
• and y is an average value ranging from about 0.5 to about 5.