The crash was reported at 8:53 a.m. on westbound Highway 37 at Railroad Avenue in Vallejo.
The big rig, which may have been cut off by another vehicle, jackknifed and spilled grapes onto the roadway, according to the CHP.
Paulson said there were no reports of injuries.
Westbound Highway 37 has been shut down at Wilson Avenue, Paulson said.
