Using a refractometer one can measure the amount of dissolved solids in fruits or vegetables, the “brix”. It’s a great way to measure the response of crops to soil or foliar amendments, by measuring sap before and after an amendment is applied. Ideally measurements are taken at the same time each day, after the plant has been exposed to at least 2 hours of sunlight.
It’s a great way to measure the quality of your produce. The Brix Chart is used for interpretation.
How to use an optical refractometer
Squeeze sap out of a plant.
Put 2 drops on the prism.
Close the prism cover.
Point to a light source.
Focus the eyepiece.
Read the measurement.
Where light & dark fields intersect is the brix number.
Using °Brix as an Indicator of Vegetable Quality
Linking Measured Values to Crop Management
Matthew D. Kleinhenz
Natalie R. Bumgarner
Department of Horticulture and Crop Science
The Ohio State University, Ohio Agricultural Research and Development Center