A "Quentchen" of luck is often exactly what one wants. The meaning is "a tiny little bit of luck".

The German word "Quentchen" is derived from the Latin "Quintus" (fifth). "Quint" was probably originally used as a name for the fifth part of a solidus or the hundredth part of a Carolingian pound. The unit of weight known as "Koelnische Mark" (in use from 1524 to 1857) was divided into 16 lots of 4 Quentchen, so one Quentchen equalled a weight of 3.654 grammes.