Surging

Surging occurs in distillation when an volume of liquid is heated beyond its boiling point without the formation of bubbles. Eventually, when a vapor bubble does form it will be substantially larger than the typical bubbles formed. As a result of this large amount of vapor being formed, the still surges and expels a lot of distillate. Surging is problematic for reflux distilling because the increased vapor flow can overwhelm the column. For pot distillation, surging is problematic because in the super heated liquid, compounds with high boiling points (such as congeners) can easily be turned into vapor. The best way to prevent surging is the use of boiling chips and the reduction of heat to the still.