A prison warden in the Central Michigan Correctional Facility says prisoners are making homemade alcohol, mostly from oranges. Because of this, fruit is no longer allowed out of the kitchen, according to The Morning Sun.

“They can make alcohol out of almost anything,” Tom Birkett said. “We call it spud juice. They just let it ferment.” He says prisoners keep the alcohol in soda or water bottles that they can buy from the prison’s commissary.

Birkett told the newspaper the problem has eased since fruit has been banned. “But we’re never going to prevent it,” he added. A prisoner’s release date could be affected by a misconduct report related to homemade alcohol.