Question and Answer Forum

MISCO Refractometer Q&A Forum

Find answers to many common questions concerning applications, operation, calibration, and maintenance of refractometers:

Beer (3)

Can your digital refractometer be used to determine balling (sugars) in distillers mash? The standard has been to use a balling hydrometer. Also would there be one to determine alcohol in the fermenting mash? The max is around 9% by volume.

Our Palm Abbe digital refractometer is ideal for measuring the sugar content of mash for beer makers. You can use either the Brix scale or the balling scale for this. Once fermentation begins a refractometer cannot be used to “directly’ measure either the sugar content or the ethanol content since they will interfere with each other. However, there are some indirect methods using the Brix scale to monitor fermentation.

We are a California manufacturer of a carbonated low-alcohol beverage and are looking for a relatively low-cost way to test samples to make sure alcohol is below 0.5%. Would your refractometer work for this?

Unless your beverage is just ethanol and water, a refractometer will not be able to directly measure the alcohol content. This is because sugars in the solution will conflict with a reading of alcohol and vice a versa. Probably the best way to test this is by distilling the beverage and measuring the distillate with a Palm Abbe digital refractometer equipped with an ethanol scale.

We use your Palm Abbe PA201 digital refractometer for making sorbet, and love it! But we’re confused as to how it operates on solutions that contain sugar and alcohol in combination: the readings don’t seem to make sense. Is there a way to compensate for this?

Unfortunately it is not possible to measure sugar contents and alcohol content in combination in a sorbet or other solution using a refractometer. Refractometers are very good at measuring binary solutions (two-part), such as water and sugar, where water is a constant and sugar is a variable. However, a refractometer is not very good for measuring multi-component solutions such as water, sugar, and alcohol. When there are several different components in a solution, such as water, sugar, and alcohol, it is difficult to tell what the contribution is that each component makes to the total refractive index. So, if the refractive index changes, it is impossible to say, with any certainty, which of the component parts changed. A refractometer only measures the total refractive index of a solution and cannot selectively read the refractive index of one particular component. All water soluble fluids look the same to the refractometer. So, depending on the concentrations of the other constituents, it may be difficult to get an accurate reading of any one component.