Coffee beans consist of 50% cellulose, which is not soluble at all. The soluble substances are only 36%, which is the maximum that can be extracted under laboratory conditions. When coffee is brewed with water, the acids are extracted first, then the sugars, and finally the bitter substances. Coffee tastes good when these substances are in balance with each other.
TDS is primarily influenced by two main factors: Ratio, which is the ratio of coffee to water: the more coffee, the higher the TDS and vice versa. Grind: The finer the grind, the higher the TDS.