Firefighters had to quickly dig a protective channel to prevent yeast spilled from a truck reaching Lake Taupo.
Police Sergeant Fane Troy said a truck and trailer unit failed to take a moderate bend on a road that intersected with State Highway One in the town at 1am yesterday.
The truck rolled and slid off the road before stopping when it hit a tree.
It was carrying a variety of goods including two containers of liquid yeast which spilt and flowed toward the lake.
The crash closed a section of SH1 until mid-morning.