A Complete Breakdown of Random Variables in Pour-Over Coffee

Why do people call pour-over coffee “unpredictable”? Why can V60, Origami, or Kalita Wave produce completely different results with the same beans and recipe? The truth is simple: Pour-over coffee has too many invisible variables. At Vihi, we turn these unknowns into measurable engineering structures.

01｜Filter Paper Variables

filter paper, kalita wave, v60 filter, paper thickness

Angle inconsistency (especially Wave filters)
Paper thickness variations
Fiber density differences
Deformation from stacking/transport

These directly affect:

Flow rate
Bypass
Bed geometry

This is why V-Fold 38.3° exists — to eliminate paper randomness.

02｜Flow Rate Variables

flow rate, turbulence, bypass, dripper geometry

Wall-side flow is always faster
Center flow is slower
Turbulence varies with pouring height
Asymmetry due to pouring direction

Every pour is a different extraction.

03｜Grind Variables (Fines)

fines, grind size distribution, unimodal, burr design Most inconsistency comes from fluctuations in fines generation. Traditional hoppers force beans to compress each other, creating fines. G-Flow solves this with:

Motor-driven rotating disc
Slow-feed geometric channel
True single-bean/small-dose feeding

Resulting in cleaner, smoother extractions.

04｜Bed Geometry Variables

bed shape, cone dripper, flat-bottom dripper Different drippers = different extraction physics.

V60 — deep bed, vertical flow
Origami — prone to ring bypass
Kalita Wave — stable, shallow bed

05｜Pouring Technique Variables

turbulence, pulse pouring, continuous pour, blooming

Pouring height
Flow rate
Circle size
Pulse vs continuous
Blooming duration

Every small motion creates a different extraction curve.

06｜Why Pour-Over Feels “Unpredictable”

Because it contains:

Filter paper variance
Flow rate variance
Fines variance
Bed geometry variance
Pouring technique variance

07｜Vihi’s Mission: Turning Randomness Into Engineering

V-Fold — eliminates paper inconsistency
G-Flow — reduces fines, stabilizes grinding
Future — engineering-based dripper systems

We engineer the parts of coffee that people once thought were unpredictable.

This is the value of Vihi.