Have you ever sipped an espresso at a café and thought it was just heavenly? One of the behind-the-scenes secrets to that perfect cup is TDS, or Total Dissolved Solids. Today, we're going to demystify TDS and see how it helps make that flawless espresso. Ready? Let’s dive in!
What is TDS?
TDS stands for Total Dissolved Solids, which refers to the combined content of all inorganic and organic substances present in a liquid in molecular, ionized, or micro-granular suspended form. Imagine pouring hot water over coffee grounds, and the water extracts all the flavors, aromas, and other magical elements from the coffee. These extracted substances are what we call TDS, which stands for Total Dissolved Solids. TDS can be measured with a nifty little tool called a refractometer, which tells you how much "good stuff" is dissolved in your coffee, usually expressed as a percentage or in parts per million (ppm).
The Ideal TDS Range for Espresso
For espresso, the ideal TDS range is generally considered to be between 8% and 12%. This range is determined based on the balance between strength and extraction:
- Strength: This refers to the concentration of coffee solids in the brew. Higher TDS means a stronger coffee with more dissolved solids, which is key for a rich and bold espresso.
- Extraction: This is the process of pulling flavors from the coffee grounds into the water. Proper extraction ensures your coffee is neither too sour (under-extracted) nor too bitter (over-extracted).
Factors Influencing TDS in Espresso
- Grind Size: Finer grinds increase the surface area of the coffee exposed to water, leading to higher TDS. However, grinding too fine can cause over-extraction and a bitter taste.
- Brew Time: The longer the water is in contact with the coffee grounds, the higher the TDS.
- Water Temperature: Higher temperatures generally increase TDS by promoting more efficient extraction of coffee solids. However, excessively high temperatures can result in bitterness.
- Coffee-to-Water Ratio: Using more coffee relative to water increases TDS, making for a stronger brew.
- Pressure: Espresso is brewed under high pressure (typically around 9 bars). Proper pressure ensures efficient extraction, contributing to the desired TDS range.
To achieve the perfect espresso TDS, these factors need to be balanced to match your personal taste and the characteristics of the coffee beans, resulting in a consistently enjoyable coffee experience.
Works Cited
23 Degrees. “Chasing strength and flavour in your brew” June 21, 2023, www.23degrees.com.au/blogs/news/chasing-strength-and-flavour-in-your-brew
