Prison officials said they had to act after an increase in the amount of hooch circulating in the jail and described it as a "serious issue".
The problem was upgraded to a red alert issue at one stage, the Independent Monitoring Board's annual report said.
Illicit alcohol production is common in some prisons but can prove dangerous.
The Howard League's Mark Gettleson described the reduction in fresh fruit as a backward step for prisoners.
"Prison food isn't known for its nutritional value. By cutting further the small amount of nutritional food its inmates receive, Lewes prison is taking a backward step," he said.
"The management's focus should be on knowing what prisoners are up to, not on taking away one of the few healthy things that exist behind bars."
A spokeswoman for the jail said: "This is a serious issue, which is why we took immediate action to tackle it.
"Our staff are extremely vigilant and use a range of measures to stop prisoners making or having access to illicit items.
"Anyone caught with such items is dealt with severely."
The IMB report, which praised much of the work at Lewes, revealed that during the latter part of last year the rise in hooch-making prompted the security department to increase the risk threat to red.
Fruit portions were reduced and other products that could be used - including five-litre cleaning containers used to make the hooch - were either removed or moved away from inmates.
As a result, the perceived risk was reduced to amber in January 2013.
The Ministry of Justice said ministers would respond in detail to the report "in due course".
Prisoner welfare campaigners have criticised a decision by Lewes jail to cut fruit rations which are being used to make illicit alcohol.