Liquid basic detergent, comprising from 2 to 10% wt.-% of one or more anionic, amphoteric or nonionic surfactants, from 35 to 45% wt.-% of one or more alkali donors, from 2 to 10% wt.-% of one or more complexing agents and from 0.01 to 2.0 wt.-% of one or more optical brighteners and having an etching alkalinity of more than 25%, characterized in that - the one or more surfactant comprises or comprise alkylpolyglycosides, - the one or more alkali donor is/are selected from potassium hydroxide and sodium hydroxide or mixtures thereof, - the one or more complexing agent is/are selected from citric acid, glycolic acid, N,N-biscarboxymethylalanine, diethylenetriaminepentamethylenephosphonic acid and combinations thereof, - the one or more optical brightener is/are selected from ∘ disodium-2-[ -2-[4-[4-[ -2-(2-sulfonatophenyl)ethenyl]phenyl]phenyl]-ethenyl]benzenesulfonate, ∘ disodium-5-[[4-[(3-amino-3-oxopropyl)-(2-hydroxyethyl)amino]-6-(phenylamino)-1,3,5-triazin-2-yl]amino]-2-[ -2-[4-[[4-[(3-amino-3-oxopropyl)-(2-hydroxyethyl)amino]-6-(phenylamino)-1,3,5-triazin-2-yl]amino]-2-sulfonatophenyl]ethenyl]benzenesulfonate, ∘ tetrasodium-5-[[4-[(3-amino-3-oxopropyl)-(2-hydroxyethyl)amino]-6-[(4-sulfonatophenyl)amino]-1,3,5-triazin-2-yl]amino]-2-[ -2-[4-[[4-[(3-amino-3-oxopropyl)-(2-hydroxyethyl)amino]-6-[(4-sulfonatophenyl)amino]-1,3,5-triazin-2-yl]amino]-2-sulfonatophenyl]ethenyl]benzenesulfonate, and wherein the basic detergent, in the temperature range from -15 to +40 °C, is present as a stable clear solution without components remaining undissolved or precipitating and forms a dispersion or suspension, said solution, in the temperature range from 0 °C to 20 °C, having a viscosity of less than 300 mPa s. - the one or more surfactant comprises or comprise alkylpolyglycosides, - the one or more alkali donor is/are selected from potassium hydroxide and sodium hydroxide or mixtures thereof, - the one or more complexing agent is/are selected from citric acid, glycolic acid, N,N-biscarboxymethylalanine, diethylenetriaminepentamethylenephosphonic acid and combinations thereof, - the one or more optical brightener is/are selected from ∘ disodium-2-[ -2-[4-[4-[ -2-(2-sulfonatophenyl)ethenyl]phenyl]phenyl]-ethenyl]benzenesulfonate, ∘ disodium-5-[[4-[(3-amino-3-oxopropyl)-(2-hydroxyethyl)amino]-6-(phenylamino)-1,3,5-triazin-2-yl]amino]-2-[ -2-[4-[[4-[(3-amino-3-oxopropyl)-(2-hydroxyethyl)amino]-6-(phenylamino)-1,3,5-triazin-2-yl]amino]-2-sulfonatophenyl]ethenyl]benzenesulfonate, ∘ tetrasodium-5-[[4-[(3-amino-3-oxopropyl)-(2-hydroxyethyl)amino]-6-[(4-sulfonatophenyl)amino]-1,3,5-triazin-2-yl]amino]-2-[ -2-[4-[[4-[(3-amino-3-oxopropyl)-(2-hydroxyethyl)amino]-6-[(4-sulfonatophenyl)amino]-1,3,5-triazin-2-yl]amino]-2-sulfonatophenyl]ethenyl]benzenesulfonate, ∘ disodium-2-[ -2-[4-[4-[ -2-(2-sulfonatophenyl)ethenyl]phenyl]phenyl]-ethenyl]benzenesulfonate, ∘ disodium-5-[[4-[(3-amino-3-oxopropyl)-(2-hydroxyethyl)amino]-6-(phenylamino)-1,3,5-triazin-2-yl]amino]-2-[ -2-[4-[[4-[(3-amino-3-oxopropyl)-(2-hydroxyethyl)amino]-6-(phenylamino)-1,3,5-triazin-2-yl]amino]-2-sulfonatophenyl]ethenyl]benzenesulfonate, ∘ tetrasodium-5-[[4-[(3-amino-3-oxopropyl)-(2-hydroxyethyl)amino]-6-[(4-sulfonatophenyl)amino]-1,3,5-triazin-2-yl]amino]-2-[ -2-[4-[[4-[(3-amino-3-oxopropyl)-(2-hydroxyethyl)amino]-6-[(4-sulfonatophenyl)amino]-1,3,5-triazin-2-yl]amino]-2-sulfonatophenyl]ethenyl]benzenesulfonate,