See Officers' servants for information about cooks for specific officers.
At least in February 1863, the company B officers' mess had a cook (Charles Leipold's testimony in Morris Kayser's court martial).
On 23 June 1863, Sinex ordered company cooks to be ready for duty in camp, and to be guards for the teams while on the march, but to be separated from the regiment only if the regimental commander thought the teams were far enough from the regiment to require that [circular, HQ 91st PA, 23 June 1863]. This is probably a response to a general order received by the regiment on 23 [?] June 1863, about arming company cooks.
Two men are listed as detailed as cooks in the September [?] 1864 list:
John Vanderslice (A), cook at Brig HQ, detailed by Col Gregory, 5 July 1864
Alexander Keeley (C), cook, detailed January 1864 by Sinex