How to Brew Better Dark Roasts by James Hoffmann
I. Preparation and Freshness
- Freshness is Key: Dark roasts stale much faster than light roasts. While they degas quicker, they should ideally be used within two to three weeks of roasting for the best flavour experience.
- Filter Choice: Use a paper filter (like V60 or Chemex). Paper filters block the "fines" (tiny coffee particles) that add an extra layer of bitterness and sediment to the cup.
II. The Ultimate Recipe Adjustments
The goal is to coarsen the grind to reduce extraction of bitter flavours, then increase the dose to maintain strength.
| Element | Recommendation | Rationale |
|---|---|---|
| Grind Size | Grind notably coarser than you would for a light roast. | Dark roasts are more soluble (easier to extract). Grinding coarser reduces the surface area, pulling out less of the harsh, bitter compounds. |
| Dose (Ratio) | Use a higher dose, closer to 70 grams per liter (70g/L). | Because you are grinding coarser (which reduces strength), increasing the dose compensates for this by maintaining the overall strength of the brew. |
| Brew Temperature | Use a Split Temperature technique for best results. | If you only had one option, a lower temperature (80°C to 85°C) would produce a softer, gentler brew. |
III. The Split Temperature Technique (Recommended)
This advanced technique is designed to capture complexity (like from a higher temperature) without extracting the dominant bitterness (like from a lower temperature).
- Bloom with Boiling Water: Start the extraction with boiling water for the initial bloom. This helps maximise degassing and pulls out a bit more complexity at the start.
- Brew with Lower Temperature: Immediately drop the water temperature and brew the rest of the coffee at approximately 80°C.
This method results in a cup with:
- More complexity.
- Plenty of extraction, body, and richness.
- A cleaner, smoother aftertaste, avoiding the harsh bitterness.
Since you are using a coarser grind, you should expect a faster overall brew time.