The present technology provides liquid quality assessment systems and methods for their preparation and use. The systems can include a light source configured to illuminate a liquid sample, a reflecting surface configured to reflect light scattered by the liquid sample, and a detector configured to detect light intensity, wherein the light source illuminates the liquid sample with a first incident light when the reflecting surface is absent; the detector detects a first light scattered by the liquid sample in response to the first incident light; the light source illuminates the liquid sample with a second incident light when the reflecting surface is present; and the detector detects a second light which is a combination of light scattered by the liquid sample in response to the second incident light and light reflected by the reflecting surface of light scattered by the liquid sample in response to the second incident light.