You enjoy a cup of coffee almost every day, but do you know how to correctly brew and serve to get the most out of your beans?
Coffee at the wrong temperature is not only an unpleasant experience but can also affect the taste. A bitter flavour might come out of what was once a nicely roasted bean while a scorched aroma may ruin a perfect blend.
How temperature can affect the taste of coffee
The taste of coffee changes due to chemical reactions that can be traced back to variations in temperature.
Coffee aroma compounds are produced in large quantities during the roasting process, when the heat of the roasting process causes sugars and other compounds found in green coffee beans to break down.
Roasting coffee beans causes their compounds to break down, producing volatile compounds that can change into gases.
These gases and volatile compounds are responsible for the taste and aroma we experience when drinking coffee.
Optimal Coffee Serving Temperature
There’s no clear answer here, and much of it does come down to personal preference.
Coffee is often served at around 80 degrees celsius. At this temperature, we get the satisfaction of drinking a hot cup of coffee, but may miss out on many of the more subtle flavours.
According to a study conducted by researchers at the University of Texas “hot beverages such as tea, hot chocolate, and coffee are frequently served at temperatures between 71.1 degrees C and 85 degrees C.”
Thus, hot beverages must be served at a temperature high enough to create a “satisfactory sensation” for the drinker.
However, as part of the research, they conducted a survey of a population of 300 subjects and found the preferred drinking temperature of coffee is around 60 degrees C.
While this may seem on the cooler side, it’s not uncommon for specialty coffee drinkers to consume their brew in this temperature range.
Coffee’s notes shine between 120°F and 140°F (49°C and 60°C), which is why we prefer this temperature. The subtle flavors noted by the roaster will come out within this range, creating a delightful cup. – Driftaway Coffee
Worth noting also is the optimal coffee serving temperature will vary depending on the brew method.
The above temperatures are from American studies so relate to American style filter coffee, so what about serving temperatures for flat whites and lattes?
Anyone who drinks coffee from specialty coffee shops or cafes will have noticed that the serving temperature has dropped slightly over the past 10 years or so. According to research conducted by The Daily Telegraph, “…it has fallen five degrees in the past few years because a growing number of people pursue fuller flavours.”
This phenomenon is not just a change in tastes, it’s occurred as coffee drinkers have switched from darker roasts to more lightly roasted arabica beans, often single origin.
Single Origin head trainer Hugh McDonnell reckons the ideal flat white should be served at 58C. – The Daily Telegraph
Single origin, and specialty coffee types of beans often have a delicate, fruity or nutty flavour profile that is best perceived at lower temperatures.
Barista feedback was that if you make coffee that’s too hot (above 68C), you lose its natural sweetness, but if it’s too cool, then you don’t develop the flavour as much.
However, consumers continue to vary widely in their preferences, and most would still consider a 58C coffee as lukewarm and unacceptable.
Optimal coffee brewing temperatures
Now that we’ve covered coffee serving temperatures, let’s take a look at optimal brew temps. This is the temperature you want your water to be at when it combines with your freshly ground coffee to perfectly extract the desired flavours and aromas.
Most coffee enthusiasts agree that water at a temperature of 96 degrees Celsius (205 degrees Fahrenheit) makes the best coffee.
This includes all the manual brewing methods such as plunger/french press, pour-over coffee, Aeropress, and drip coffee.
Above this temperature, you risk over-extraction. Brewing coffee at too high a temperature can result in bitter, unpleasant-tasting coffee.
Likewise, making coffee using water that’s too cold can prevent the full flavour of the coffee from being extracted.
For espresso, a similar brew temperature is required.
The optimal brewing temperature for espresso is between 90 and 96°C. At a hotter temperature you may end up with more extracted coffee but it may taste burnt and bitter. Cooler temperatures, on the other hand, extract coffee at a slower rate and potentially lead to under-extraction and less flavourful espresso.
Cold brew is usually brewed in the fridge at temperatures around 3C, but can also be brewed at room temperature.
If you’re short on time and want a smooth cup of cold brew, then choose room temperature instead of the fridge.
Cold water extracts flavours slower, so if you’re brewing in the fridge, you’ll need even more time (12-16 hours).
The best temperature for steamed milk
For espresso and milk based coffee, the barista or home brewer must take into account the temperature both of the espresso itself, as well as the temperature of the steamed milk.
In specialty coffee, milk is generally steamed to between 55 and 62°C. This can be measured using a thermometer however most baristas will use their hand on the milk jug to determine when it has reached the desired temperature.
According to The Daily Telegraph research mentioned earlier “Steaming the milk beyond 68C robs milk of its velvety texture and natural sweetness — compromising the full taste of coffee beans.”