About

Precision in brewing distinguishes a mediocre cup from an exceptional one. This tool is designed for baristas and home brewers who demand exact control over their Extraction Yield and Total Dissolved Solids (TDS). Unlike basic calculators, this engine accounts for Liquid Retained Ratio (LRR) - the water absorbed by the coffee grounds (approx. 2g per 1g of coffee) - providing a realistic estimate of the final beverage volume.

For Iced Coffee (Japanese Style), the calculator utilizes a thermodynamic displacement algorithm. It splits the total water volume into hot brewing water (for proper extraction) and ice mass (for immediate cooling and dilution), ensuring the final beverage retains the correct strength and prevents the "watery" taste associated with standard brewing over ice.

The system supports a vast database of methods, from the percolation dynamics of a V60 to the full immersion of a French Press, automatically adjusting the recommended ratio R and grind size based on global specialty coffee standards.

Formulas

The calculator employs the following logic to ensure extraction consistency:

1. Basic Ratio Logic:

m_water = m_coffee × R

2. Iced Coffee (Split):

m_ice = m_{total_water} × 0.40

m_brew = m_{total_water} × 0.60

3. Estimated Beverage Yield:

V_yield ≈ m_water − (m_coffee × 2.1)

Note: The 2.1 coefficient represents the absorption factor where coffee grounds retain approximately twice their weight in liquid.

Reference Data

Method	Ratio Range	Grind Size (μm)	Guideline
Espresso	1:1.5 - 1:3	200 - 400 (Fine)	High pressure (9 bar). Short contact time.
Moka Pot	1:7 - 1:10	400 - 600 (Fine-Med)	Steam pressure. Boiling water contact.
AeroPress	1:11 - 1:16	400 - 800 (Versatile)	Hybrid immersion/pressure. Highly variable.
Pour Over (V60)	1:15 - 1:17	600 - 900 (Med)	Percolation. Constant fresh water flow.
Chemex	1:15 - 1:16	800 - 1000 (Med-Coarse)	Thick paper filter removes oils/sediment.
French Press	1:12 - 1:15	1000+ (Coarse)	Full immersion. Rich body, more sediment.
Cold Brew	1:4 - 1:12	1200+ (Ex. Coarse)	Long contact (12-24h). Low acidity.
SCA Cupping	1:18.18	600 - 800 (Med)	Industry standard for grading coffee.

Frequently Asked Questions

The "Golden Ratio" typically refers to 1:16.67 (60 grams of coffee per 1 liter of water). This falls squarely in the SCA (Specialty Coffee Association) recommended range for achieving a Total Dissolved Solids (TDS) of 1.15% to 1.35% and an Extraction Yield of 18% to 22%.

When brewing iced coffee directly (Japanese method), you cannot simply brew a standard cup and add ice, as it will become diluted and watery. Our Ice Mode calculates a "Concentrate". It reduces the hot water volume (usually by 40%) so you brew a stronger liquid directly onto the calculated mass of ice. The melting ice then dilutes the coffee to the perfect final strength.

Coffee grounds are porous and absorbent. They retain approximately 2 milliliters of water for every 1 gram of coffee. If you pour 250ml of water over 15g of coffee, you will only drink about 220ml. This tool calculates that loss so you know exactly how much liquid ends up in your cup.

Yes. Ratio determines *potential* strength, but grind size determines *flow rate* and *contact time*. If you use a coarse French Press grind for an Espresso ratio (1:2), the water will gush through in 5 seconds, resulting in a sour, under-extracted shot. Match the grind to the method.