Can coffee make you feel drunk, or is it just extraction?

Coffee cannot make you drunk in the alcoholic sense. What people describe as feeling drunk is usually the result of extraction differences: the same beans brewed as cold brew and as iced pour-over taste like two different coffees. Cold brew's low-temperature slow extraction gives rounder acidity, a fuller body and light fermentation notes, while hot or iced pour-over keeps more aroma layers.

A controlled test with Huakui 8.0 beans showed the split clearly. The iced pour-over carried strawberry and citrus notes with creamy, honeydew-like sweetness and a refreshing entry. The cold brew showed berry and citrus aromas, softer acidity, a thicker mouthfeel and a hint of fermentation. Caffeine content, not alcohol, explains any jittery or lightheaded feeling.

Many coffee enthusiasts have wondered: why does cold brew and iced pour-over made from the same coffee bean taste so different? Front Street Coffee once conducted a comparative experiment with Huakui 8.0, and the results were surprising. This article will systematically analyze the core differences between cold brew coffee and pour-over coffee from the perspectives of extraction water temperature, extraction method, and concentration changes, explaining why low-temperature slow extraction brings rounder acidity, a fuller body, and unique fermentation aromas, while high-temperature fast extraction preserves richer aroma layers. If you also want to understand the essential difference between these two brewing methods, read on.

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Many friends at Front Street stores always like to order a cold brew, plus an iced pour-over made with the same beans, wanting to compare the two themselves and see exactly how they differ. Almost every time, they are surprised to find that although the beans are exactly the same, the two taste like completely different coffees.

So where exactly does this difference show up? Front Street once conducted a controlled experiment, using the same Huakui 8.0 coffee beans to make cold brew and iced pour-over separately (considering that the temperature difference between hot pour-over and cold brew is too great for direct comparison, only iced pour-over was used as a reference). The specific extraction parameters can be seen in the figure below:

The production steps are skipped here, but after the cold brew coffee is completed, it needs to be filtered and two ice cubes added, after which tasting can begin.

In the tasting, the iced pour-over Huakui presented strawberry and citrus fruit notes, accompanied by creamy and honeydew-like sweetness, with a refreshing entry, full body, and quite rich aroma layers (of course, still slightly inferior compared with hot pour-over); while the cold brew Huakui showed berry and citrus aromas, rounder acidity, a thicker mouthfeel, and a hint of fermentation.

It can be seen that even with the same beans, the final coffee produced will still be clearly different. The reason is not complicated — just like the same ingredient, steaming, frying, and stewing produce different flavors, and the same is true for coffee. Cold brew and pour-over use different extraction processes, so the coffee they make naturally has its own characteristics.

Some may ask: the difference between espresso and pour-over is not this big, so why is the difference between pour-over and cold brew so obvious?

Where is the difference between pour-over and cold brew?

This brings us to the most fundamental difference between the two during extraction — water temperature.

Pour-over coffee, whether hot or iced, uses high-temperature hot water for extraction. Hot water can quickly dissolve the flavor substances in coffee, so a pot of pour-over usually takes only 2 to 3 minutes to complete. But high temperature also means aromas are lost faster, and it needs to be drunk as soon as possible after brewing.

Cold brew coffee is completely the opposite, using low-temperature cold water for extraction. The dissolution rate of ice water is very low, so cold brew cannot be completed as quickly as pour-over; instead, it needs a greatly extended extraction time to achieve sufficient extraction. Generally speaking, cold brew needs 8 to 12 hours, and some methods even steep it for 24 hours.

The longer the steeping time, the higher the coffee concentration usually is. Cold brew coffee kept at low temperature can be stored for about 5 days. As storage time lengthens, the flavor expression gradually declines, but the fermented taste increases accordingly.

However, note that the extraction water temperature affects not only the extraction time, but also directly relates to the extraction rate of different components in coffee.

As is well known, coffee contains many substances such as quinic acid, amino acids, tannic acid, caffeine, and oils, which together make up the taste of coffee. The degree to which these substances dissolve is affected by water temperature; the lower the water temperature, the harder it is to extract certain substances.

Take caffeine as an example; it is one of the main contributors to coffee's bitterness. When the water temperature is too low, caffeine is difficult to dissolve out (the dissolution speed is slower). Therefore, even if the extraction rate is comparable, cold brew coffee will have much fewer bitter substances than pour-over (the influence of concentration will also be mentioned below), even if the extraction time is extended. And flavors balance one another — a cup of coffee is mainly composed of sour, sweet, and bitter tastes. When bitter substances decrease, the proportion of sour and sweet flavors is amplified. This is why cold brew does not taste so bitter.

In addition, the different extraction methods also cause flavor differences. Pour-over uses drip extraction, that is, water passes through the coffee bed and brings out the coffee's flavor substances; while cold brew belongs to immersion extraction, in which coffee grounds and water are mixed and steeped for a long time, allowing flavor substances to slowly dissolve out (Front Street has also often mentioned the difference between these two recently).

Coffee extraction relies on the concentration gradient: soluble substances diffuse from inside the coffee grounds (high-concentration area) into the water (low-concentration area) until the concentrations of the two reach equilibrium. Because drip extraction constantly refreshes the liquid concentration, coffee substances continue to be released outward, and the extraction efficiency is relatively high. But because the coffee grounds are often extracted unevenly, some more and some less, the coffee shows richer layering.

In immersion extraction, because the liquid sits still for a long time, the concentration cannot be refreshed, and after equilibrium is reached, the extraction efficiency decreases. But because all the coffee grounds are in the same environment, although the coffee made by immersion extraction is less layered, it tastes more balanced and has a thicker mouthfeel.

In addition, cold brew coffee increases its fermented flavor through resting, so its difference from pour-over coffee is further widened.

Oh, I almost forgot the difference in concentration! Although iced pour-over and cold brew have the same coffee-to-water ratio of 1:10, the purpose of using ice cubes differs between the two, resulting in different coffee concentrations. Adding ice cubes to pour-over is mainly to lower the temperature, achieving rapid cooling through contact with the hot coffee liquid. But because the temperature difference is too large, the ice melts more, and the coffee concentration is naturally diluted more noticeably;

The ice cubes used in cold brew are mainly to maintain low temperature while appropriately diluting the concentration. Because the temperature difference between the coffee liquid and the ice cubes is not large, the ice melts very slowly, so the coffee concentration is not greatly affected. Concentration also affects the intensity of coffee flavor and mouthfeel. Therefore, even if cold brew coffee and pour-over coffee use the same coffee beans, they will still differ significantly for the reasons above.

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