What is the ideal water temperature for light roast?

Water temperature is one of the most critical variables in coffee extraction, acting as the energy source that drives the dissolution of flavor compounds. When brewing light roast coffee, the bean structure is more intact and dense compared to darker roasts, which have been broken down further by the roasting process. This density makes light roasts more resistant to extraction, requiring more thermal energy to unlock their full potential.

While traditional brewing advice often suggests a range of 90°C to 96°C, light roasts generally perform best at the higher end of this spectrum. Temperatures near 95°C or 96°C help to pull out the delicate floral and fruity notes that define high-quality light roasts. If the water temperature is too low, you will likely fail to extract the sugars, leaving the coffee tasting predominantly sour or 'grassy.'

It is important to note that temperature is not a 'set it and forget it' variable. As you brew, the water temperature will naturally drop as it hits the room-temperature grounds and the brewing vessel. Using a pre-heated kettle and warming your brewer can help maintain the target temperature throughout the extraction process. If you find your light roast tastes sharp or acidic, increasing your water temperature by a few degrees is often the first adjustment to make.

In practice, the ideal temperature can also depend on your specific brewing method and the roast level of the beans. A very light, high-altitude bean might benefit from the hottest water your kettle can provide, while a slightly more developed light roast might taste better at 93°C. Experimenting within this 93°C–96°C range allows you to fine-tune the balance of acidity and sweetness, ensuring you get the most vibrant flavor profile possible from your beans.