How Many Times Can You Rebrew Pour-Over Coffee? How Many Times Can You Brew Drip Bag Coffee? Can Coffee Be Brewed Multiple Times Like Tea?

Why Coffee Shouldn't Be Brewed Multiple Times

It can be said that regardless of the brewing method used, coffee grounds are used only once. After we brew a cup of coffee, the remaining grounds in the filter are directly discarded. That's why FrontStreet Coffee believes that many times, friends inevitably wonder: why can't coffee be brewed multiple times?

FrontStreet Coffee doesn't find it surprising that such thoughts arise, because like tea, coffee is a beverage that requires water as a medium to dissolve substances. Since tea leaves can be brewed multiple times, wouldn't the same logic apply to coffee?

Indeed! If we wanted to, a portion of coffee grounds could be brewed multiple times like tea leaves. This is because coffee beans consist of about 70% woody fiber and 30% soluble substances. These soluble substances are the primary source of coffee's flavor. They adhere to the cell walls of coffee beans, dissolve when exposed to water, and are extracted along with the flow of hot water! If we were to use tea brewing methods for coffee, then even with multiple or prolonged brewing, these coffee grounds would still release flavor. Due to low extraction efficiency, only a small amount of substances would dissolve each time, without complete dissolution. Even with normal extraction, we could perform a second brew for the same reason. Then some friends might ask: "FrontStreet Coffee, FrontStreet Coffee, since coffee grounds can be reused for brewing, why do so few people do it?"

The answer is actually quite simple: because coffee made this way is terrible to drink!

The Science Behind Single-Use Coffee Brewing

Why isn't multiple brewing recommended for coffee? We call the process of water dissolving coffee substances "extraction," and the percentage of coffee substances extracted by hot water relative to the total amount is called "extraction rate." Generally, the extraction rate for each cup of coffee we brew will be around 18%-22%. Because within this range, coffee exhibits excellent flavor characteristics. If we were to describe a cup of light-roast coffee, FrontStreet Coffee would say its performance would be pleasantly sweet and sour with a full body.

The reason we limit it to within 22% is because not all of the 30% soluble substances in coffee are desirable. A cup of coffee is primarily composed of four flavors: sour, sweet, bitter, and salty. These flavors have different dissolution rates due to differences in molecular size (note: while dissolution rates vary significantly, they dissolve simultaneously). The first substances to dissolve in large quantities are sour flavors, followed by sweet flavors, and finally bitter flavors. Because sour and sweet substances dissolve in large quantities during the initial extraction phase, when the extraction rate reaches 22%, the sour and sweet substances in the coffee are nearly depleted. And these, precisely, are the essence of a good cup of coffee. Therefore, if we continue extracting after reaching 22% of the soluble substances, the coffee liquid released afterward will likely only contain off-flavors and woody fiber.

If this portion of coffee liquid were added to the previously properly extracted coffee, it would make the coffee full of harsh and astringent flavors, and because this liquid's concentration is too low, it would also dilute the original coffee's concentration. If consumed separately, which is what we call secondary brewing, there's no point either, because this portion of coffee liquid tastes weak when consumed alone, with just a hint of off-flavors.

Conclusion

Therefore, we can understand that the main reason coffee isn't recommended for multiple brewing is that we have already extracted all the "essence" of the coffee in a single extraction. The remaining substances simply cannot justify our reason for repeated brewing. After all, there's absolutely no need to do so~

Important Notice :

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FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473