In steam-and-water distillation the plant material is packed into the still pot sitting on a grill or perforated plate above the boiling water. The capacity of the still pot volume is reduced but it may be possible to achieve a high packing density because the plant material is not suspended in the water. The advantages of steam and water distillation are as follows:

• Higher oil yield.
• Oil component less susceptible to change due to wetness and thermal conductivity of the still from the heat source.
• The effect of refluxing is minimised.
• Oil quality more reproducible.
• Faster process so more energy efficient.