What Coffee Made From: How Serving Temperature Changes Taste

Coffee is made from the roasted and ground seeds of the coffee plant, brewed with hot water. How it tastes depends heavily on serving temperature. Sweetness reads strongest near body temperature, bitterness grows as the cup cools toward room temperature, and sourness barely shifts. That is why hot pour-over coffee shows its most complete flavor between 35°C and 45°C.

Aroma drives most of what is perceived as flavor, so the fragrance vs aroma coffee distinction matters here. Freshly brewed coffee releases the fullest aroma; as it cools, those top notes fade. In a washed Geisha, jasmine and citrus dominate while hot, then give way to honey sweetness once cooler. Thermos storage and reheating both flatten aroma, so drink it hot or iced.

At what temperature does coffee taste most fragrant? This is actually closely tied to how our taste buds perceive flavor. The tongue's sensitivity to sourness, sweetness, and bitterness changes with temperature, and since aroma is released to different degrees at different temperatures, hot pour-over coffee has an ideal tasting range. From Front Street Coffee's perspective, this article explains how temperature affects flavor, analyzes why freshly brewed coffee shouldn't be drunk immediately, and answers related questions about thermos bottles, reheating, and iced pour-over. Finally, Front Street Coffee will also share its consistent advice on "drink it hot or drink it iced."

"Generally speaking, when drinking coffee, the temperature had better not exceed 55°C!" "Why is that?" "Because it'll burn your mouth."

Alright, enough joking around! Now it's time for some serious nonsense.

Front Street Coffee has pretty much figured this question out. What this friend really wants to know is: at what temperature does coffee show its best flavor, tasting most fragrant and most comfortable? To understand this, we can't start from the coffee itself. We first need to get to know our taste buds. The tongue can perceive five tastes, among which sourness, sweetness, and bitterness in coffee are the easiest for us to pick up. And coffee happens to be a mixture of sour, sweet, and bitter substances.

Generally speaking, when sour and sweet substances outweigh bitterness, the cup of coffee will show a sweet-and-sour fruity character, which is the flavor we like. If bitterness stands out, or sourness dominates alone, then it is not so appealing. Temperature also affects our perception of sourness, sweetness, and bitterness. Sweetness is strongest when the temperature is above and close to human body temperature. Bitterness becomes more obvious as the temperature drops (toward room temperature). As for sourness, our perception of it is basically unaffected by temperature.

On top of that, the main source of flavor when we drink coffee is aroma. Freshly brewed coffee has the fullest aroma, and after the temperature drops, the aroma also becomes dull. For example, in a cup of washed Geisha, when hot you can smell (and taste) rich jasmine and citrus flavors, while after it cools, the jasmine and orange aromas are no longer so prominent, replaced instead by the sweet fragrance of honey. This is not to say that coffee tastes bad once it cools, but that after it cools it is not as flavor-rich as when hot. Therefore, hot pour-over coffee is suitable for tasting in the 35-45°C range. Brewed with 90°C water, a cup of coffee can be made in about two minutes, at which point the temperature is around 65-70°C. Such a high temperature easily burns the tongue, and when it is too hot it is also hard to taste the flavor. So if the coffee is too hot, you might as well smell the aroma first; this is also part of tasting coffee.

Of course, you can also do as coffee professionals do and taste from high temperature all the way down to low temperature, experiencing how the coffee's flavor changes at different temperatures. Some friends also ask, if you put coffee into a thermos or reheat it, can you preserve the flavor? The answer is no. If you put it in a thermos and finish it within an hour, the impact is small, but if you leave it for a long time or let it cool and then reheat it, the aroma compounds that have already volatilized will not come back, so the previous flavor cannot be restored. Another friend may ask, you say the lower the temperature, the more obvious the bitterness, so why don't I feel that when drinking iced coffee? Here we have to talk about how iced coffee is made. The common iced pour-over method is to extract the early and middle stages of the coffee, then add ice cubes to cool and dilute it.

In other words, the relatively large amount of bitter substances in the middle and later stages is not extracted, so in iced pour-over, the sour and sweet flavors are enough to outweigh the bitterness, which is why it doesn't taste bitter. But if you compare the aroma of iced coffee and hot coffee, the difference between the two is enormous.

So guests often ask Front Street Coffee whether this coffee is better brewed hot or iced. Front Street Coffee's usual answer is: hot coffee gives a more complete flavor and sensory experience, but in the end, whether to drink it hot or iced must come down to your own preference.

The above content is compiled by CoffeeHunters, a coffee news website.