Coffee Extraction Formula

Hi, I’m working on a thesis that want to create a coffee refractometer with light sensor and include with extraction calculator software in it. I wanna ask you all how to count the extraction if we already get the TDS%? I’ll use this formula for the extraction calculator software.


The extraction of the dose is equal to the TDS of the beverage. Extraction(Dose)=TDS(Beverage) or ED=TB.

If one brews a pourover with a 20 gram dose to produce a 350 gram beverage at 1.3% strength then:
E(20)=1.3(350). E=22.75%

That’s a simple way to calculate it anyway. The Coffee Tools app factors in a couple of other details but they make a small difference in the calculation.