The Science
Clarity in Every Cup
Stiir was developed through controlled laboratory testing and refined with performance specialists.
Clarity in Every Cup
Stiir was developed through controlled laboratory testing and refined with performance specialists.
We measure what you actually drink — not what sits in the bean.
Controlled Extraction Protocol
18g
Ground coffee
90°C
Water temperature
5 min
Steep time
250ml
Final brew volume
Three independent batches were brewed under controlled conditions and analysed using a validated chemical assay at Sheffield Hallam University.
Independent Laboratory Verification
271.7mg
Mean Total Polyphenols
Standard deviation ±5.0
185.3mg
Mean Natural Caffeine
Standard deviation ±5.1
Download the full independent lab report: Download PDF →
Methodology Matters
Polyphenol testing can be misleading depending on how it is conducted. Some brands measure antioxidant content in the raw, unbrewed coffee bean.
Raw Bean Testing
Measures compounds present in dry ground coffee. Does not reflect what is absorbed once brewed and filtered.
Brewed Cup Testing
Measures compounds in the final liquid you actually consume. Accounts for extraction, dilution and real preparation.
You don’t eat coffee grounds. You drink brewed coffee. That is what we measure.
The Role of Caffeine & Polyphenols
Caffeine
In calibrated doses, caffeine enhances alertness, reaction time and endurance. Precision matters more than exaggeration.
Polyphenols
Chlorogenic acid and related compounds provide antioxidant support linked to cardiovascular and metabolic health.