Method of operating an apparatus for providing a milk-air emulsion (MLE), the apparatus at least comprising: a) a milk line through which milk flows, b) at least one air feed system having an adjusting unit for setting an air feed amount for producing a milk-air emulsion (MLE) from the milk (M), c) at least one measuring unit for determining at least one physical material property of the milk-air emulsion (MLE), and d) a control and evaluation unit , which is designed for setting at least one control variable, e) wherein the device has at least two operating modes, f) wherein in a first operating mode, a milk-air emulsion (MLE) is dispensed, g) wherein, in the first operating mode, an addition amount of air is introduced into a supplied milk (M), wherein the control and evaluation unit sets the air addition amount on the basis of a data set which has been determined when passing through a second operating mode, h) wherein in the second operating mode, in the context of a self-adjustment, the data set is created by changing the physical material property by changing the supplied amount of air by means of the adjusting unit , and i) wherein the apparatus, in the first operating mode, enables dispensing of a beverage comprising a milk-air emulsion, wherein step i) is characterized in that , that it includes the following steps: A) presetting a milk-air emulsion (MLE) based on a manual selection of a beverage; B) executing the first operating mode while enabling a control panel for setpoint adjustment of the amount of air within a setpoint range set in the second operating mode; and C) dispensing of the beverage with the milk-air emulsion (MLE). a) a milk line through which milk flows, b) at least one air feed system having an adjusting unit for setting an air feed amount for producing a milk-air emulsion (MLE) from the milk (M), c) at least one measuring unit for determining at least one physical material property of the milk-air emulsion (MLE), and d) a control and evaluation unit , which is designed for setting at least one control variable, e) wherein the device has at least two operating modes, f) wherein in a first operating mode, a milk-air emulsion (MLE) is dispensed, g) wherein, in the first operating mode, an addition amount of air is introduced into a supplied milk (M), wherein the control and evaluation unit sets the air addition amount on the basis of a data set which has been determined when passing through a second operating mode, h) wherein in the second operating mode, in the context of a self-adjustment, the data set is created by changing the physical material property by changing the supplied amount of air by means of the adjusting unit , and i) wherein the apparatus, in the first operating mode, enables dispensing of a beverage comprising a milk-air emulsion, wherein step i) is characterized in that , that it includes the following steps: A) presetting a milk-air emulsion (MLE) based on a manual selection of a beverage; B) executing the first operating mode while enabling a control panel for setpoint adjustment of the amount of air within a setpoint range set in the second operating mode; and C) dispensing of the beverage with the milk-air emulsion (MLE). A) presetting a milk-air emulsion (MLE) based on a manual selection of a beverage; B) executing the first operating mode while enabling a control panel for setpoint adjustment of the amount of air within a setpoint range set in the second operating mode; and C) dispensing of the beverage with the milk-air emulsion (MLE). <EOS>