The all-wet process uses coconut milk extracted from raw coconut rather than dried copra. The proteins in the coconut milk create an emulsion of oil and water.  The more problematic step is breaking up the emulsion to recover the oil. This used to be done by prolonged boiling, but this produces a discolored oil and is not economical. Modern techniques use centrifuges and pre-treatments including cold, heat, acids, salts, enzymes, electrolysis, shock waves, steam distillation, or some combination thereof. Despite numerous variations and technologies, wet processing is less viable than dry processing due to a 10–15% lower yield, even taking into account the losses due to spoilage and pests with dry processing. Wet processes also require investment of equipment and energy, incurring high capital and operating costs.