Tracking TDS in your brew is an accurate way to evaluate how much of the coffee grounds have been extracted into your brew. The TDS reading helps you evaluate the strength and balance of your coffee. It may seem complex, the process is simple when equipped properly.

To get started you will need a refractometer, which is a precision tool that measures the degree of light deviation in a fluid. The angle of light deflection changes based on the concentration of dissolved substances in the liquid. In coffee brewing, those substances are mainly the flavorful, water-soluble elements from the beans.

Before you start make sure your refractometer is accurately adjusted. You’ll usually find a calibration solution, usually distilled water. Place a few drops on the prism, gently clamp the housing, and use the built-in calibration protocol to set the zero point. Clean the optical plate with a non-abrasive cleaning tissue after each use to avoid residue buildup.

Then brew your coffee following your standard recipe. Once it’s ready, wait until it stabilizes at 20–25°C. The measurement is temperature-sensitive, so it’s important that the reference liquid and your brew are at matching ambient conditions, ideally around 20 to 25 degrees Celsius. If your refractometer has temperature compensation, it will adjust automatically. But manual models require you to align both samples exactly.

Via a sterile transfer tool, place two to three microliters of liquid onto the prism. Press down evenly to ensure full contact across the surface. Check the LCD readout, depending on your device. Your instrument will output a reading in percent or Brix, which represents the total dissolved solids as a percentage of the total weight of the coffee.

To make sense of the number, you can use a TDS-to-extraction chart or brewing guideline. A typical espresso might show a TDS between 8 and 12 percent, while a filter coffee commonly displays from between 1.2% and 1.5%. The TDS value by itself doesn’t indicate if the coffee is well-extracted or off. But they give you an objective reference.

Pair your TDS value with your grounds-to-water proportion to calculate extraction yield, which tells you what percentage of the coffee grounds were dissolved.

Consider this scenario: if you used 20 grams of coffee and 300 grams of water, your ratio is 1:15. If your TDS is 1.4 percent, your you’ve extracted roughly 21% of the grounds, پارتاک کافی which is widely accepted as perfect for drip methods. If you’ve under-extracted, your coffee may feel acidic and thin. Should extraction exceed the target, it might taste bitter or overdone.

Tracking dissolved solids enables you to make repeatable, data-driven improvements. It replaces intuition with metrics and permits consistent duplication of perfect results. With practice, you’ll learn how particle distribution, heat level, and steep duration affect the numbers, and you can fine tune your process for consistently exceptional results. While not necessary for casual drinkers, it’s a powerful tool for those pursuing brewing excellence.