A fermented mash made from any of a number of ingredients, but most freq from the skimmings of boiling sugarcane juice, used directly as a beverage or distilled into moonshine; hence combs cane buck, corn ~, grape ~, persimmon ~, sugarcane ~.
1904 Thomasville Times–Enterprise (GA) 11 Mar /1 (newspaperarchive.com), A crowd of colored people had been drinking “cane buck,” and a quarrel arose. 1914 Times–Enterprise Semi-Weekly (Thomasville GA) 20 Jan /3 (newspaperarchive.com), They smashed about twelve stills this week. . . One of them would hold forty gallons of buck or booze. 1918 Herring Sat. Night Sketches 38 csGA, In a few days when the “skimmings” ferment—there is cane beer, delicious with its sweet-sour taste, and still later “buck” from the same stuff, now at a stage when only the initiated can appreciate it, ready for the hard drinker or the wildcat still. 1920 Daily Times–Enterprise (Thomasville GA) 14 Oct 6/4, We searched the premises . . and found in an old out house one barrel of grape buck and one tub of persimmon buck. 1921 New Smyrna News (FL) 14 Jan 1/3, The still, together with about 200 gallons of buck, was destroyed. 1933 Rawlings South Moon 91 FL, The boy was prowling around the wooden barrels of mash. . . “You git out o’ there, Lant!” Piety spoke sharply. “You’ll spile your Uncle Zeke’s buck.” 1938 Thomasville Times–Enterprise (GA) 5 Feb 4/5, Edmond Jones . . had imbibed too freely in corn buck and was evidently thrown from his bicycle when he struck a rut in the road. 1940 Sat. Eve. Post 6 Apr 55 seGA, neFL, Occasionally he’d drink a gourd of cane buck. . . [He] wondered if the buck made him say what he said then. 1955 AmSp 30.158, Other names [for sugarcane beer] . . are: buck or cane buck . . , Florida . . and sugar-cane buck, Georgia. 1966 News Tribune (Ft. Pierce FL) 22 Nov 5/8, Buck, it was explained, is a drink made of rice, corn, barley and yeast, or any combination of these ingredients. 1966–70 DARE (Qu. DD21c, . . Illegally made whiskey) Inf FL52, Shine, home brew, buck; (Qu. DD25, . . Nicknames . . for beer) Inf FL7, Swill (covers buck, i.e., homemade beer); GA19, Buck (beer moonshine is made from); GA26, Corn buck—beer that is made into moonshine; GA30, Buck—corn beer before moonshine is distilled; NC49, Buck—out of a barrel before it’s ready to run; (Qu. DD28a, . . Liquor other than beer, wine, or whiskey) Inf FL7, Cane buck; (Qu. DD28b, . . Fermented drinks . . made at home) Inf FL7, Beer, corn buck, mulberry wine; FL34, Buck—homemade beer; FL52, Buck—grapes and yeast; very local; GA7, Corn buck: corn, sugar, meal fermented—not distilled; GA26, Corn buck; SC26, Persimmon buck (beer). 1986 Pederson LAGS Concordance (Home-brewed beer or whiskey) 10 infs, chiefly nFL, sGA, Buck; 5 infs, 3 cs, swGA, Corn buck; 3 infs, cs, swGA, Cane buck; 1 inf, seGA, Buck beer. 2013 in 2017 DARE File—Internet sGA, Every year we make syrup my grandfather talks about how his daddy used to make “cane buck”. He was very young the last time he saw it made and was never told the recipe/technique.