☕️ Dialed In: The Anatomy of an Espresso Shot and How to Master It

☕️ Dialed In: The Anatomy of an Espresso Shot and How to Master It

by REL Coffee | The Chemist’s Journal

Espresso is small but unforgiving. When it’s right, it’s rich, balanced, and layered. When it’s off—even by a little—it’s sharp, bitter, or hollow.

At REL, we build every roast with espresso in mind. We think about extraction like a process: controlled, intentional, and repeatable. You don’t need fancy language or expensive tools—just an understanding of what matters and how to adjust it.

Here’s a full breakdown of what shapes an espresso shot, how to get the best from your machine, and what to do when something’s not quite right.

1. Coffee Origin — Start With the Right Bean

The region your coffee comes from affects how it behaves under pressure.

What to Expect by Region:

• Ethiopia: Bright, floral, delicate. Easy to under-extract (sour).
• Brazil: Chocolate, nutty, low acidity. Great for base espresso.
• Colombia: Balanced and clean. Performs well across roast levels.
• Guatemala: Cocoa, spice, and mild fruit. Very versatile.
• Sumatra: Earthy, low acid. Thick body but less clarity.

General Rules:

• High-acid beans → May need a longer shot time or slightly higher dose to soften edges.
• Low-acid, chocolatey beans → Work best with a shorter ratio or finer grind to boost flavor.

2. Roast Profile — Solubility and Flavor Go Hand in Hand

How a coffee is roasted determines how easily it extracts and what flavors show up.

Roast Levels and What They Mean:

• Light Roast
  • More acidity, less solubility.
  • Best for: longer shots (1:2.5 ratio), hotter temps (202–204°F), finer grind.
• Medium Roast
  • Balanced sweetness and clarity.
  • Best for: standard 1:2 ratio, 198–202°F.
• Dark Roast
  • Lower acidity, more body, easier to extract.
  • Best for: shorter shots (1:1.5), cooler temps (194–198°F), coarser grind.

Roast Correction Tips:

• Tastes sharp or sour? Go slightly darker or extract longer.
• Too bitter or burnt? Lighten the roast or reduce shot length.

3. Grind Size — Where Most Problems Start

Grind controls how fast or slow water flows through your coffee. It’s your most powerful adjustment tool.

General Rule:

• Too fine = slow shot → bitter, muddy, over-extracted.
• Too coarse = fast shot → sour, watery, under-extracted.

How to Adjust:

• Start with 18g in → aim for 36g out in 25–30 seconds.
• Shot pulling too fast (<20s)? Grind finer.
• Shot choking or stalling (>35s)? Grind coarser.

4. Dose and Yield — The Espresso Equation

The amount of coffee in (dose) and liquid out (yield) shapes your shot’s strength and texture.

Basic Recipe (Start Here):

• 18g in → 36g out
• Time: 25–30 seconds

Adjusting Ratios:

• Ristretto (short shot):
  • 18g in → 27g out
  • Tastes: dense, syrupy, intense
• Lungo (long shot):
  • 18g in → 45g+ out
  • Tastes: lighter, more bitter, less body

Correction Tips:

• Want more body? Use a shorter yield (1:1.5).
• Want more clarity or brightness? Go longer (1:2.5 or 1:3).

5. Pressure and Flow — The Hidden Hands

Most machines use 9 bars of pressure. It works—but flow rate and preinfusion (how fast water starts soaking the coffee) matter just as much.

Basics:

• Too much pressure or too fine a grind = channeling or choking.
• Too little pressure = flat, weak shots.

Home Barista Tips:

• If your machine allows:
  • Try 3-5 seconds of preinfusion before full pressure.
  • Watch the shot: steady flow, even color. Sudden lightening = over-extracted.

6. Water — The Quiet Variable

Espresso is 90% water. Bad water ruins good coffee.

Water Specs:

• Temp: 195–204°F (depends on roast)
• TDS (solids): 75–150 ppm
• Hardness: Moderate
• Avoid: Distilled or unfiltered well water

Taste Clues:

• Sharp or metallic? Could be water pH or hardness.
• Flat or chalky? Check mineral content.

7. Troubleshooting — How to Fix Bad Shots

Conclusion: Think in Variables, Not Magic

Espresso doesn’t need to be mysterious. It’s not luck—it’s a balance of inputs. When you understand how origin, roast, grind, dose, and pressure interact, you can fix nearly anything.

Start with a baseline:

• 18g in → 36g out → 25–30 seconds
• Adjust one variable at a time
• Keep notes (real ones—on paper or phone)

That’s what we do at REL. We test, adjust, and trust the process. Because coffee doesn’t need to be complicated—just cared for.

📌 Summary: Espresso Dial-In Cheatsheet