Water temperature is one of the most misunderstood variables in home coffee brewing. Most people either boil their water and pour immediately, or let it cool to room temperature by accident. Both extremes hurt your coffee.
The Extraction Sweet Spot
Water between 90°C and 96°C extracts coffee optimally for most roast levels. This range dissolves the right balance of acids, sugars, and aromatic compounds that create a flavourful, balanced cup.
- Below 85°C: Under-extraction — sour, flat, underdeveloped coffee
- 85–90°C: Acceptable for very light roasts, but generally too cool
- 90–96°C: The sweet spot for most coffee
- 97–100°C: Over-extraction — harsh, bitter, can scorch delicate compounds
Light vs Dark Roast
Roast level affects how easily compounds extract. Light roasts are denser and require higher temperatures (93–96°C) to extract fully. Dark roasts are more porous and extract quickly — use slightly cooler water (88–92°C) to avoid bitterness.
The Simple Rule: Boil and Wait
You don't need a thermometer. Bring water to a full boil, then let the kettle sit off the heat for 30 seconds before pouring. This reliably drops temperature to around 93–95°C — right in the sweet spot for medium roasts.
For dark roasts, wait 60 seconds. For very light roasts, pour almost immediately after boiling.
Why a Gooseneck Kettle Helps
Temperature matters more for pour-over brewers, where precise control over where and how fast you pour directly affects extraction. A gooseneck kettle lets you pour in slow, controlled circles — which is more important for V60 than the temperature difference of 2–3 degrees.