How the simulator models French Press extraction

French Press in the simulator

The French Press is the full-immersion method in the simulator. Ground coffee rests in direct contact with hot water for several minutes, with no paper filter to retain oils or fine particles. The result is a fuller-bodied drink with more texture than the V60, with a rounder profile.

The simulator models the French Press with three basic parameters: grind, ratio and steep time. Temperature is an optional advanced parameter (default 93 °C).

Model note: the simulator does not measure real extraction, but a heuristic index (0–100) that combines the brewing variables. That index determines both the position on the extraction map and the shape of the flavor radar. It is not a TDS percentage or a real extraction yield (EY).

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Simulator variables: French Press

Grind (0–100)

In the French Press, grind has the highest extraction weight (up to 28 points in the model), but its dynamics differ from espresso or V60. Without a paper filter, too fine a grind has two consequences:

1. It increases extraction, quickly pushing toward over-extraction.
2. It adds astringency to the radar, since the model applies an astringency bonus for fine grinds (grindAstringency = (1 - grindN) × 8, inverse: coarser grind reduces this bonus).

The recommended grind for French Press in real practice is coarse. In the simulator, values of 20–50 represent coarse to medium grinds, more suitable for this method.

Ratio (1:10–1:18)

The simulator range for French Press is 1:10 to 1:18 (water-to-coffee). The usual standard is 1:14–1:16.

• Low ratio (< 1:12): more concentrated and fuller-bodied cup. The model boosts body for low ratios (up to 18 bonus points).
• Standard ratio (1:14–1:16): typical working zone.
• High ratio (> 1:16): more diluted and lighter cup for a method that already produces full-bodied drinks.

In the model, ratio does not only dilute the drink: it also increases the extraction index by extending the water–coffee contact. A longer ratio means more water in contact with the same coffee bed during the steep, extracting more solubles even at equal grind and time.

Total steep time (seconds)

Total steep time is the duration of the immersion. The typical range is 120–360 seconds (2–6 minutes). The default in the simulator is 240 s (4 minutes).

• More time: more extraction. Up to 14 additional points in the model (time normalized over 300 s).
• Less time: less extraction, more acidic and lighter cup.

Unlike the V60, time in the French Press has no independent bloom phase: the infusion is continuous and passive. The simulator does not calculate any internal bloom for this method.

Temperature (advanced, 80–96 °C)

Temperature is an advanced parameter in the French Press. The model range is 80–96 °C, wider than the V60 (90–96 °C), because the French Press can be brewed at lower temperatures without severely penalizing extraction, thanks to the long steep time.

• High temperature (> 90 °C): increases extraction and raises bitterness in the radar.
• Low temperature (< 85 °C): less extraction, more perceived acidity, softer profile.

The default is 93 °C. If advanced mode is disabled, the engine always uses 93 °C.

Water hardness: GH and KH (advanced)

Behavior is analogous to other methods:

• High GH: more body and sweetness.
• High KH: reduces perceived acidity.

In the French Press, body is already naturally high (due to the absence of a paper filter), so GH has less perceptible impact than in the V60.

Roast and process

The effects of roast and process are the same as in other methods: roast shifts state thresholds and adds biases to the radar; process modulates the sensory radar without affecting extraction.

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How it reflects in the extraction map

The map positions the recipe in the grind-ratio space, just like other methods. For the French Press:

• The balanced zone is reached with low-to-medium grinds (20–55) combined with standard ratios (1:13–1:16).
• Very fine grinds with long time quickly push to over-extraction.
• Steep time is a visible secondary modifier: more time shifts the point toward more extraction.

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How it reflects in the flavor radar

The radar does not represent isolated flavors, but the overall balance of the simulated extraction. Each axis reflects how the extraction index and the modifiers for roast, process and advanced parameters combine in the specific French Press you have configured.

The French Press radar has a distinctive profile compared to V60 or espresso:

• Higher body base: the engine starts with a body base of 35 (vs. 15 for V60 or 25 for espresso). The absence of a paper filter is encoded in this higher base.
• Lower acidity base: the acidity starting point is 60 (vs. 75–80 for other methods). Full immersion extracts fewer volatile acids than filter methods.
• Astringency sensitive to fine grind: the model adds a specific astringency bonus when grind is fine, which does not exist in other methods.
• Sweetness bell peaking at E=48: slightly lower than espresso (52) or V60 (50). French Press reaches peak sweetness at a somewhat lower extraction.

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Typical combinations and common readings

| Scenario | Symptom | Why it happens | Suggested adjustment | |---|---|---|---| | Acidic, watery cup | Under-extracted | Coarse grind or short time → low index → high acidity | Grind finer or increase steep time | | Strong bitterness, dry texture | Over-extracted | Fine grind or long time → high index | Grind coarser or reduce time | | Marked astringency | Very fine grind + long time | The engine applies an explicit astringency bonus for fine grind in French Press | Grind coarser | | Low body for a French Press | Very high ratio | High ratio reduces the engine's body bonus inherent to full immersion | Reduce ratio to 1:14 | | Soft, round profile | Balanced with medium roast | Medium roast maximizes sweetness and reduces extreme biases in the radar | Target zone |

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Balanced, under-extracted and over-extracted in French Press

Under-extracted: extraction below 38. Acidic, light cup without the characteristic body of the method. Radar with high acidity and low body.

Balanced: extraction in the optimal zone (38–65 for medium roast; 38–70 for light; 38–60 for dark). The radar shows prominent body, moderate sweetness and contained acidity. A balanced French Press is a round, textured cup without sharp edges.

Over-extracted: extraction exceeds the high threshold. Bitterness and astringency rise. Over-extraction in French Press is particularly unpleasant because oils and fine particles are unfiltered: excess extraction is accompanied by dense, dry textures.

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Technical section: how the simulator models the French Press

General heuristic

extraction = 10 + grindN×28 + ratioN×20 + tempN×8 + timeN×14

Where:

• ratioN = (ratio − 10) / 8 (range 10–18)
• tempN = (temperature − 80) / 16 (range 80–96)
• timeN = min(time / 300, 1)

Temperature has the lowest weight of the four drivers (8 points) because in the French Press the long contact time drives extraction far more than temperature does. Time, in contrast, has the highest weight in this method (14 points), reflecting that steep duration is the most important lever.

Sensory projection

The most significant difference from espresso and V60:

• High body base (35): explicitly encodes the no-filter effect. In espresso it is 25, in V60 it is 15.
• Low acidity base (60): full immersion extracts more uniformly; volatile acidity is not lost as in pour-over but neither concentrated as in espresso.
• Fine-grind astringency bonus: grindAstringency = (1 − grindN) × 8. This term is exclusive to the French Press and models the effect of fine particles that pass through the metal filter.

Simplifications and limits

• The model does not reproduce sedimentation of the grounds or the effect of the plunger. Steep time is treated as linear up to 300 s, without modeling concentration changes during sedimentation.
• The default temperature of 93 °C applies when advanced mode is disabled. The 80–96 °C range allows exploring cooler brews, although in real practice the difference between 85 and 93 °C in French Press is less perceptible than in the V60.
• The model does not differentiate between a small French Press (2 cups) and a large one (8 cups). The dose is always fixed at the simulator value (18 g base).

The model prioritizes interpretability over physical precision: the goal is for the user to understand how to adjust variables and develop extraction intuition, rather than exactly reproducing the behavior of a real French Press.