(Yesterday, 19:26)cyrusct82 Wrote: 92°C
Ratie 1:3 (așa beau de obicei)
![[Image: WOEK9a2.jpeg]](https://i.imgur.com/WOEK9a2.jpeg)
This screen is from a **WPM Primus** showing a **pressure/flow profiling graph** for espresso extraction. Here’s what the curves represent:
## The Axes
- **Left (Red scale 0–10):** Pressure in bars (standard espresso pressure)
- **Right (Blue scale 0–4):** Flow rate in mL/s (or similar flow metric)
- **X-axis:** Time (55-second total shot window)
## The Curves
**Blue Line (Flow):**
- **0:00–0:10:** Rapid ramp to 9.5–10 bar equivalent flow (actually this is the pump pushing water; the spike suggests a pre-infusion bypass or initial pressure surge)
- **0:10–0:18:** Sharp decline as the puck saturates and resistance builds
- **0:18–0:35:** Bottoms out near zero (pressure builds, flow chokes)
- **0:35–0:55:** Gradual recovery to steady 2 mL/s extraction
**Red Line (Pressure):**
- **0:00–0:15:** Delayed start (pre-infusion phase where pressure is held low/closed)
- **0:15–0:35:** Ramp up to peak 9 bars (full extraction pressure)
- **0:35–0:55:** Gradual decline to 5 bars (pressure tapering/declining profile)
## What This Profile Does
This is a **"pressure-profiling"** shot, likely:
1. **Pre-infusion (0–15s):** Low pressure saturates the puck evenly (red line stays flat/low while blue shows initial water delivery)
2. **Ramp-up (15–35s):** Pressure climbs to full 9 bars for extraction
3. **Decline/Taper (35–55s):** Pressure bleeds off while flow stabilizes, reducing channeling risk and smoothing the finish
**Result:** A 55-second "long" shot designed for high extraction with controlled acidity—common for light-roast specialty coffee where you want to extend contact time without over-extracting bitter compounds.
The flat white line at 1.5 on the right axis likely represents your **target flow rate** or a reference line for the profile.
