What is TDS in Coffee and how to get?
If you are a beginner in coffee-making, you may have heard words in cafés or extraction competitions that make you wonder, such as coffee TDS or Shimmy Coffee Sieve. TDS and other pesky acronyms are sometimes long and confusing, but when you understand coffee TDS, you'll see that they're actually simple to grasp.
Let's start with TDS.
What is TDS?
Only 30% of the total mass of a coffee bean is soluble; the other 70% is made up of insoluble fibers and carbohydrates which form the structure of the bean. When the ground-up coffee beans are immersed in hot water, the soluble part of the coffee dissolves in the water, these parts are then called dissolved solids.
Coffee Total Dissolved Solids(TDS) represents the proportion of dissolved solids in a cup of coffee.In other words, it tells you how much material has been released from the coffee beans and entered your coffee.The substances released during the extraction process determine the flavors of your coffee, and the TDS determines the strength of those flavors.
TDS Number
The higher the value, the higher the concentration of "coffee" in your coffee. Unfortunately, higher coffee TDS values are not always better. About 20% of the soluble matter in the beans is delicious, and the other 10% tastes terrible. In order to brew the best tasting coffee we must strive to free up the good soluble matter while keeping the unenjoyable soluble matter locked in the beans.
For a cup of pour-over coffee, SCA counted habits of most people, It comes that 1.15 to 1.45%
TDS is usually considered delicious. For a cup of Prismo, people like the taste of 3.5 to 5% TDS.
We collected some TDS references below:
Pour--Over: 1.2—1.5% TDS
AeroPress® Coffee Maker: 1.4—1.7% TDS
French Press: 1.4—1.7 % TDS
Prismo: 3.5—5% TDS
Espresso: 8—12% TDS
When making your own coffee, TDS values may vary, depending on the extracted coffee, on the size of the grind, the brewing time and the brewing method. You can play around and find out which type of coffee you like best and determine TDS value of your preferred flavor.
If you record the size of the grind, the brewing time and method, you can also record the TDS value, then you can check which combination of techniques provides you with the optimal coffee experience.
How to measure TDS?
If you are a scientist or a lab technician, you can probably put the coffee on your gas chromatograph coupled to a mass spectrometer or other very fancy instruments. But for the average user who wants to enjoy a nice cup of coffee, this is very impractical.
Our portable TDS meter is way easier to use. It works like that: light rotated by different angle
as it passes through liquids of different concentrations. We can measure the degree of rotation
of light as it passes through the liquid, and then rely on a computer to derive the concentration.
So, not only can it determine the TDS value of your coffee, it can also help you find out about
the ingredients of other beverages. Amazing, right?
How to measure?
In order to measure the TDS, you need to prepare:
- A TDS refractometer
- Dropper
- Distilled water
- Paper towel
- Your coffee (of course!)
Before the actual measurement, you need to calibrate your coffee TDS refractometer with water.
Please see the instructions below.
After the calibration is completed, you can start the measurement. The steps of the measurement are as follows:
After the coffee TDS measurement is completed, please rinse the refractometer with clean water or distilled water for the next use.
DiFluid refractometers are all equipped with automatic temperature compensation, wherever you are, the automatic temperature compensation can depress affect of temperature. However, we still suggest you measure TDS after your coffee reach room temperature, which can help you get a more accurate result.
TDS and Golden Cup
About TDS number and connection with good coffee, SCA comes out a ‘Golden cup standard’, The chart is showed below. If you want to know deeper about Golden cup and how to use, please pay attention to other articles on our website.
How to buy?
In addition to coffee TDS meter,DiFluid also produces sugar meters for agricultural. We will produce more instruments for coffee in the future, please visit https://www.digitizefluid.com if you want to learn more!
