GT3 BREWVOL. 02
THE METHODOLOGY
A treatise on what is in the cup

The chemistry
behind the signal.

Coffee is not one substance. It is a system of compounds, inputs, environment, and time. GT3 Brew is built to control the variables most coffee ignores.

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Brewed in a controlled environment.
Measured by scale and refractometer, every batch.
§ CONTINUED ↓
01 / Selectivity

Hot pulls. Cold selects.

Every compound in a coffee bean has its own dissolution temperature. Hot water is indiscriminate — it pulls almost everything. Cold water is choosy. It dissolves the gentle, the aromatic, the structural — and leaves the harsh and broken-down behind in the grounds.

The bean has a thousand molecules. We extract the right ones.

HOT EXTRACTION
Indiscriminate
Aggressive solvent. Pulls the gentle and the harsh in the same pass. Heat fractures delicate compounds.
COLD EXTRACTION
Selective
Time replaces heat. The molecules that should reach the cup do. The ones that shouldn't, don't.
02 / Selection

What we preserve. What we refuse.

PRESERVE

What reaches the cup.

Compounds that survive cold extraction intact.

Caffeine
C₈H₁₀N₄O₂ · highly water-soluble
Extracted nearly fully — without the rough phenolics that ride alongside it in hot brew. Alertness without the edge.
Chlorogenic Acids
C₁₆H₁₈O₉ · the antioxidant family
Cold extraction keeps them whole. Hot brewing fractures a meaningful share into harsh quinic and caffeic fragments. We don't.
Citric & Malic Acids
gentle organic acids
Bright, structural, easy on the stomach. Their harsher cousins stay in the grounds.
Aromatic Volatiles
esters, aldehydes, terpenes
Heat-sensitive flavor compounds. Hot brewing steams them off. Cold leaves them dissolved — chocolate, fruit, floral, intact.
Trigonelline & Melanoidins
roast-formed antioxidants
Surface during roast. Survive cold extraction without degrading. Carry through to the cup.
REFUSE

What stays in the grounds.

Compounds we leave behind, untouched.

Quinic & Caffeic Acids
CGA breakdown byproducts
The harsh, sour, stomach-irritating acids that form when chlorogenic acids are cooked. Cold doesn't crack them open.
Oxidized Lipids
peroxides, aldehydes from rancid oils
Rancidity precursors that drive off-flavors and cloudiness. Paper-filter pulls minimize transfer.
Furan Compounds
heat-formed byproducts
A class of compounds formed at high temperature. Cold extraction doesn't reach the temperature required to create them.
Heavy Phenolics & Tannins
drying, astringent compounds
Mouth-drying, mineral-binding, bitter-finishing molecules of hot brew. The cup feels softer because it physically is.
Excess Oxalates
C₂H₂O₄ · dissolves more in heat
Pulled aggressively by hot water. Friendlier to oxalate-sensitive systems when extracted cold.
03 / Protection

For hours, the brew breathes.

Cold extraction has no thermal kill step. The brew sits in contact with its environment for hours. The air, the vessel, the light, and the temperature are inputs too — we treat them that way.

What reaches the cup is what we allowed.

Variable
What it does
How GT3 controls it
Airborne particles
DUST · SPORES · FIBERS
Anything floating in a kitchen — dust, mold spores, fabric fibers — will settle on an open vessel during a long brew window.
Filtered air. Sealed vessel. The brew window is closed to particulate.
VOCs & odors
CLEANING · COOKING · SMOKE
Volatile ORGANIC compounds dissolve into open vessels. The brew can take on the character of whatever is happening in the room.
Dedicated brewing space. No shared kitchen environment. The room itself is part of the recipe.
Light exposure
UV · VISIBLE SPECTRUM
Light degrades chlorogenic acids and aromatic compounds. Even ambient light slowly reshapes flavor over a long extraction.
Light-blocked vessel during the entire brew window. Stored cold and dark afterward.
Temperature drift
EXTRACTION KINETICS
Solubility curves are not linear. A few degrees changes which compounds extract and at what rate. Drift produces inconsistency.
Held within a defined cold range, logged across the brew. Stratification is prevented.
Cross-contamination
BATCH-TO-BATCH CARRYOVER
Yesterday's brew residue hosting today's microbes. Glass and stainless are inert; the surrounding system can still be the contaminant.
Glass-only vessels. Sanitized between every batch. No carryover allowed.
04 / Receipts

Measured, not guessed.

These are the process specs we hold every batch to. They aren't aspirations — they're the controllable inputs that make the output reproducible.

Lab-verified outcome claims will be added to this page after independent testing concludes.

Brew window
12–18HR
Cold extraction takes time. The window is the lever, not the temperature.
Cold range
CONTROLLED
Held within a defined cold range across the brew. Logged, not assumed.
Concentration
REFRACTOMETER
Every batch read for total dissolved solids. Variance flags it; release blocks until corrected.
Inputs
SCALE-WEIGHED
Coffee and water measured to the gram. Volume estimates don't ship.
Vessel
GLASS · INERT
Glass-first throughout the process. Nothing leaches in. Nothing carries over.
Additives
NONE
No flavorings. No emulsifiers. No preservatives. The bean and the water.
05 / The Commitment

Reproducibility is the product.

GT3 Brew is not built on vibes. Every batch is designed around controlled inputs, measured extraction, and repeatable sensory output.

Five levers. Held the same, every time.

01
Input
Bean origin, roast, grind, water. Specified, not estimated.
02
Process
Cold, slow, paper-filtered. The same protocol every time.
03
Environment
Air, light, temperature, vessel. All controlled inputs.
04
Measurement
Scale, refractometer, batch log. Every variable read.
05
Feedback
Honest taster signal in. Better signal out, next batch.

Test the signal yourself.

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