cellar rat
n.β Β«He will be at the winery for six months working as what is known as a cellar ratβsomeone who does odd jobs around the winery during the vintage.Β» ββJob winner as happy as a rat in a cellar” by Bernard Carpinter Stuff.co.nz Mar. 1, 2006. (source: Double-Tongued Dictionary)
Cellar Rat is a term which has been around for years within the wine / winery business. It’s a title not intended to be derogatory.