Decreasing Extraction with a Fixed TDS
You determine a shot is a touch too dry and bitter, and you want to reduce extraction but maintain your TDS.
You are brewing on an 18–40g ratio with a TDS of 9%.
40g beverage weight at 9%TDS and 20% extraction yield
You increase the dose to 18.5g and you coarsen the grind (or decrease the temperature).
- This change will shift your extraction yield by 20% down to 19.5%.
40g beverage weight at 9%TDS and a 19.5% extraction yield
This is the opposite situation to the previous example. Increases of just one gram of coffee above your standard dose could increase your coffee bill by a little over $2000 per year. Using a typical cafe profit and loss scenario (10% net profit per annum, an average of 300 coffees per day at $20 per kilo wholesale) can mean $20,000 in sales are needed to compensate for this increase in dosage. Standard business practice should see espresso items on the menu priced 0.5g above the standard dose to allow for increases in dose when chasing TDS or extraction targets.