Sarah Chen
Senior Coffee Reviewer & Grinder Specialist
Q Grader Certified (CQI) | SCA Certified | 12+ Years Cupping & Grinder Testing
About Sarah Chen
Sarah Chen's coffee career started in the cupping labs of San Francisco's Blue Bottle Coffee, where she spent four years as a quality-control cupper before earning her Q Grader licence from the Coffee Quality Institute in 2014. That certification — one of the most rigorous in the coffee industry, requiring passing 22 individual sensory and technical exams — gave her a scientifically grounded framework for evaluating flavour, consistency, and equipment performance that she has carried into every review she has written since.
Specialising in grinder technology, Sarah has personally tested more than 100 burr grinders across consumer and prosumer categories, measuring particle-size distribution with a Kruve Sifter Pro and comparing grind uniformity using a calibrated digital micrometer. She has consulted for specialty coffee shops in the San Francisco Bay Area on equipment selection and has contributed grinder methodology pieces to Roast Magazine and Perfect Daily Grind.
Sarah joined The Coffee Locator in 2018 as Senior Reviewer. She holds SCA certification across the Brewing and Sensory modules and applies a structured 25-point grinder scoring rubric — covering burr geometry, static, retention, grind uniformity, and stepless adjustment range — to every grinder she evaluates. Her work is peer-reviewed by Michael Anderson before publication.
"Grinders are underrated. Most people obsess over the machine, but 70% of shot quality lives in the grinder. I test grinders the way a lab scientist would — with consistent inputs, measured outputs, and no emotional attachment to brand reputation. Numbers don't lie."
Professional Certifications
- Q Grader Licence — Coffee Quality Institute (2014)
- SCA Coffee Skills Programme — Brewing & Sensory modules (2016)
- Certified Cupping Judge — Specialty Coffee Association
Key Achievements
- Passed all 22 Q Grader exams — Coffee Quality Institute (2014)
- Personally tested 100+ coffee grinders with particle-distribution analysis
- Published grinder methodology in Roast Magazine and Perfect Daily Grind
- Consulted for specialty coffee shops in the San Francisco Bay Area
- 12+ years of formal specialty coffee cupping and sensory evaluation
Career Timeline
- 1
Quality Control Cupper
Blue Bottle Coffee, San Francisco CA
Conducted daily production cuppings; developed tasting vocabulary and sensory calibration across single-origins and blends.
- 2
Q Grader Certification
Coffee Quality Institute
Passed all 22 Q Grader examinations including olfactory, triangulation, grading, and roast identification modules.
- 3
Equipment Consultant
Independent — San Francisco Bay Area
Began advising specialty cafés on grinder and brewer selection; developed first structured grinder scoring rubric.
- 4
SCA Certified — Brewing & Sensory
Specialty Coffee Association
Completed SCA Coffee Skills Programme Brewing and Sensory modules.
- 5
Senior Coffee Reviewer
The Coffee Locator
Joined as lead grinder specialist; expanded methodology to 25-point grinder scoring rubric using Kruve particle-size analysis.
- 6
Contributing Writer
Roast Magazine & Perfect Daily Grind
Published peer-reviewed grinder methodology pieces reaching a combined audience of 400,000+ coffee professionals.
Testing Methodology
Each grinder is tested over a minimum of 30 days with at least 5 kg of coffee across three grind-size ranges (filter, espresso, and coarse/pour-over). Static retention is measured by weighing the hopper before and after each grind cycle. Particle distribution is analysed with a Kruve Sifter Pro using a six-sieve stack. Grind uniformity scores are derived from the bi-modal ratio — the proportion of fines vs boulders relative to the target sieve size. All results are recorded in a standardised spreadsheet and averaged across three separate test dates before a score is assigned.
Testing Equipment Used
- Kruve Sifter Pro — particle-size distribution analysis
- Digital micrometer — burr gap calibration verification
- Acaia Pearl scale — 0.1 g resolution for retention measurement
- VST Refractometer — extraction yield for grind-comparative brew tests
- EK43 reference grinder — baseline uniformity benchmark
- Still Air Box — static charge measurement environment
Published In
- ›Roast Magazine — "A Measurable Framework for Evaluating Burr Grinders"
- ›Perfect Daily Grind — "Particle Distribution: What It Means for Home Brewers"
- ›The Coffee Locator — Lead reviewer, 100+ grinder evaluations
Consulted For
- ›Sightglass Coffee, San Francisco CA
- ›Ritual Coffee Roasters, San Francisco CA
- ›Verve Coffee Roasters, Santa Cruz CA
- ›Multiple independent specialty cafés across the Bay Area
Guides by Sarah Chen
How to Choose a Burr Grinder
Expert guide to choosing the perfect burr grinder — burr types, grind settings, pricing, and essential features for better coffee.
Manual vs Electric Grinders
Expert comparison of manual and electric coffee grinders — pros, cons, and best use cases for each type.
Burr vs Blade Grinder: Which Should You Buy?
Why burr grinders produce a better cup — and when a blade grinder might still make sense for your situation.
Coffee Grind Size Chart
A complete visual grind size chart for every brew method — espresso through cold brew — with dialling-in tips.
How to Pick Espresso Beans
How to choose perfect espresso beans — bean types, roast levels, freshness, and flavour profiles for amazing shots.
What Is Coffee Bloom?
The bloom (pre-infusion) stage explained — what CO₂ degassing does to your cup and how to get it right.
What Is Espresso Crema?
Espresso crema explained — what it tells you about freshness, extraction quality, and grind consistency.
Why Does Coffee Taste Bitter?
Root-cause guide to bitter coffee — identifying whether the problem is grind, temperature, extraction time, cleanliness, or bean age.
What Is Espresso? Expert Barista Guide
Everything you need to know about espresso — what it is, how it is made, and why it is the foundation of every café drink.
What Is a Ristretto?
Ristretto vs espresso vs lungo — what changes when you restrict the shot and why it affects flavour intensity.
What Is a Lungo?
The lungo explained — ratio, extraction time, and how it compares to an Americano in taste and strength.
What Is a Doppio?
The doppio — a double espresso shot — explained: how it differs from a single, when to order one, and how to pull it correctly.
What Is a Cortado?
The cortado: espresso 'cut' with an equal part of warm milk. Origins, ratio, how it differs from a macchiato.
What Is a Macchiato?
Espresso macchiato vs latte macchiato explained — the key ratio difference and why it matters for flavour.
What Is a Cappuccino?
Classic cappuccino: espresso, steamed milk, and microfoam in equal thirds. Origin, technique, and how to make one perfectly.
What Is a Flat White?
Flat white vs latte vs cappuccino — the milk texture and ratio differences that define each drink.
Flat White vs Cappuccino vs Cortado
Expert comparison of three milk-based espresso drinks — milk ratios, foam texture, calories, strength, and preparation technique.
Latte vs Cortado: Key Differences
Side-by-side comparison of latte and cortado — caffeine, flavour intensity, calories, and milk ratios explained.
Macchiato vs Latte
Expert breakdown of macchiato vs latte — espresso ratio, milk foam, preparation technique, taste, and calories.
7 Alternative Espresso Drinks to Try
Looking beyond lattes? Discover 7 espresso drinks that are stronger, less milky, or more adventurous — with expert barista guidance.
Coffee Drinks Differences: Beginner Guide
Types of coffee drinks explained for beginners — espresso drink differences, milk ratios, caffeine comparisons, and ordering tips.
Americano vs Espresso: Key Differences
How an Americano differs from straight espresso — dilution ratio, flavour profile, and when to choose each.
How to Make a Café Americano
The correct method for making an Americano at home — ratio, pour order, and hot vs iced variations.
How to Make Iced Latte at Home
Step-by-step iced latte guide — espresso ratio, milk choices, and how to avoid a watered-down drink.
How to Make Cold Brew Coffee
Step-by-step cold brew guide — grind size, ratio, steep time, and equipment recommendations.
Moka Pot: What It Is and How It Works
The moka pot explained — stovetop espresso mechanics, grind recommendations, and why it tastes different from a machine.
How to Use a Moka Pot
Step-by-step moka pot brewing guide — grind size, water level, heat setting, and common mistakes to avoid.
Pour Over Coffee: Complete Guide
Everything about pour over — bloom, grind, temperature, and pour technique for a clean, flavourful cup.
Drip vs Pour Over Coffee: Expert Guide
Drip coffee vs pour over compared — flavour clarity, control, equipment cost, and which suits your lifestyle.
Product Reviews by Sarah Chen(19)
Blue Bottle Coffee Three Africas Review
illy Classico Review
Intelligentsia Black Cat Classic Review
Lavazza Super Crema Review
Onyx Coffee Lab Geometry Review
BALMUDA The Brew Review
Fellow Aiden Review
Outin Mino Review
Baratza Encore ESP Review
Baratza Virtuoso+ Review
Comandante C40 Review
Turin DF64 Gen 2 Review
Eureka Mignon Specialita Review
Fellow Ode Gen 2 Review
Fellow Opus Review
KINGrinder K7 Review
Mavo Phantox Pro Review
Timemore Chestnut C3 Review
