γ-Decalactone is an industrially interesting peach-like aroma compound that can be produced biotechnologically through the biotransformation of ricinoleic acid. Castor oil (CO) is the raw material most used as the ricinoleic acid source. The effect of different CO concentrations on the γ-decalactone production by Yarrowia lipolytica was investigated in batch processing, and 30 g L−1 was found to be the optimal oil concentration. Under these conditions, cells were able to produce lipase but at low activity levels, which might limit ricinoleic acid release and consequently, the γ-decalactone production rate. Thus, the enzymatic hydrolysis of CO by commercial lipases was studied under different operating conditions. Lipozyme TL IM was found to be the most efficient and the optimal hydrolysis conditions were pH 8 and 27 °C. The use of hydrolyzed CO in the aroma production allowed a decrease in the lag phase for γ-decalactone secretion.