A large-scale clean-up operation has been carried out after a tanker carrying more than 20 tonnes of waste yeast overturned on the M1.
The lorry, initially reported to be carrying Marmite, crashed and spilt its contents onto the carriageway at about 22:15 GMT on Monday.
Police closed the motorway in both directions between junctions 32 and 33 near Sheffield following the accident.
The Highways Agency said both carriageways had since reopened.
A spokeswoman for South Yorkshire Police said the tanker overturned after being involved in a collision with a motor caravan.
The tanker driver was taken to hospital but the driver's injuries were not believed to be serious.
The Environment Agency was called in to assist in the clean-up after fears that the yeast could pollute local waterways.
Environment Agency area incident controller Colin Atkinson said: "Brewers yeast can have a devastating impact on wildlife in watercourses because it strips the water of oxygen, suffocating the fish.
"Our incident team worked with the Highways Agency to create a bund to contain the yeast. This prevented it from flowing into nearby Ulley Brook and the River Rother which is an important coarse fishery and is used by many anglers.
"Tankers were brought in to take the yeast waste away and our environment officers are checking oxygen levels in the waterways to make sure no pollution has escaped."