The Best Way to Drink Cold Drip Coffee: Recommended Single-Origin Coffee Beans and the Unique Characteristics of Cold Drip Black Coffee

Before we know it, September has arrived again. Our friends in the southern regions are likely still battling daily with the passionate sun, as the weather remains quite hot. For coffee lovers, the first refreshing beverage that comes to mind is undoubtedly iced coffee. When you visit FrontStreet Coffee, you'll immediately notice a coffee vessel that resembles a chemistry experiment apparatus. Many curious customers approach to investigate what it is. Actually, this vessel is used for making cold drip coffee. In this article, FrontStreet Coffee will explain what cold drip coffee is and how to make it.

The Origin of Cold Drip Coffee

It is said that cold drip coffee was invented by the Dutch, which is why it's also known as Dutch-style drip coffee. Unlike other brewing methods that require hot water, cold drip coffee is characterized by using ice water to extract coffee. This low-temperature extraction requires more time to dissolve the aromatic substances from the coffee.

Therefore, using a dropper similar to those in chemistry experiments, ice water drips drop by drop, slowly moistening and permeating through the coffee grounds. In traditional cold drip coffee makers, the dripping speed can usually be adjusted.

What is the Extraction Principle of Cold Drip Coffee?

Cold drip coffee is a type of coffee that requires time to develop. Coffee brewed with different water temperatures will yield different flavors. At low temperatures, the astringent substances in coffee are less likely to be extracted. Using ice water for long-term extraction, and then fermenting it in the refrigerator after extraction is complete, results in cold drip coffee with a subtle fermentation aroma and a richer mouthfeel. Since it's not extracted through high temperatures, fewer impurities are extracted from the coffee, and the caffeine content is slightly lower.

What's the Difference Between Ice Water Extraction and Hot Water Extraction?

Temperature affects the breakdown rate of oils, acids, and sugars in coffee. Depending on how quickly this process occurs, the aroma, flavor, and texture of coffee can vary significantly, so different extraction methods can produce coffee with distinct flavors and mouthfeels. High-temperature extraction causes tannic acid in coffee to quickly break down into pyrogallic acid, creating sour, sweet, and bitter flavors—what FrontStreet Coffee often refers to as the process of releasing coffee flavors. Excessively hot water can cause coffee flavors to be released too quickly, followed by the release of woody fiber flavors from coffee beans, resulting in what we commonly call off-flavors or unpleasant woody tastes.

Low-temperature extraction involves prolonged contact between water and coffee grounds at cold temperatures. Only smaller flavor molecules, such as floral and fruit aromas, are extracted, while larger flavor molecules like smoky and roasted flavors are difficult to extract. Therefore, cold brew coffee better showcases the inherent flavors of coffee beans, with a smooth mouthfeel, distinct layers, and noticeable aftertaste.

Tips for Making Cold Drip Coffee

1. Grind Size

Similar to pour-over coffee, the grind size for cold brew requires attention. Too fine a grind creates dense channels, leading to over-extraction and bitter flavors; too coarse a grind increases the likelihood of channel effects, resulting in under-extraction and bland coffee. FrontStreet Coffee recommends using a slightly finer grind than pour-over coffee. FrontStreet Coffee uses a #20 standard sieve with a 75-85% pass rate as reference, which is similar in coarseness to sugar granules.

2. Coffee-to-Water Ratio

FrontStreet Coffee suggests using a 1:10 to 1:12 ratio for cold drip coffee. Coffee extracted within this ratio range can be consumed directly or diluted with ice cubes to achieve a moderate concentration for tasting.

3. Please moisten the coffee grounds before dripping, and remember to place filter paper on top of the coffee grounds layer.

Moistening the coffee grounds ensures they are in a water-saturated state before extraction, facilitating the drip extraction process. Also remember to place a piece of filter paper on top of the grounds—this filter paper helps distribute water droplets evenly across the coffee grounds. Otherwise, the resulting coffee might be too weak!

4. Cold drip coffee tastes better after being stored in the refrigerator overnight.

FrontStreet Coffee typically soaks it overnight for about 12-14 hours, so the next day we can remove the coffee grounds and obtain the extracted coffee liquid. FrontStreet Coffee once forgot and left it soaking for more than a day—the resulting coffee liquid was bitter and harsh, so everyone needs to pay attention to controlling extraction time to avoid waste. Additionally, the storage space for coffee can absorb various odors from the air. If we store it in a home refrigerator, FrontStreet Coffee recommends choosing a container with good sealing to avoid flavor contamination.

Why Should Cold Drip Coffee Be Fermented in the Refrigerator for Over 12 Hours After Drip Filtration? Is This Process Really Called Fermentation?

Actually, rather than calling this step fermentation, it's better to describe it as an oxidation process. Just like freshly roasted coffee beans, which contain about 2% carbon dioxide by weight. As these large amounts of carbon dioxide are released depending on storage environment, equipment, or methods, the pressure in the packaging becomes higher than atmospheric pressure. This pressure helps aromatic substances and oils to merge, bringing all aromatic substances inside the coffee beans to a state where they can be easily extracted.

The same applies to cold drip coffee. Due to the long extraction time, many flavor molecules are extracted but not fully released. Therefore, when cold drip coffee extraction is complete, placing it in a sealed bottle and letting it sit in the refrigerator for 12-24 hours creates carbon dioxide pressure inside the bottle, allowing flavor molecules to be released. This is also why cold drip coffee becomes more concentrated the longer it stays in the refrigerator. Of course, FrontStreet Coffee doesn't recommend storing cold drip coffee for a week—after all, there are bacteria in the air or bottles, making it difficult to guarantee the state of coffee after prolonged storage. The recommended consumption period for cold drip is within 72 hours. After 72 hours, don't feel it's a waste to discard it—coffee stored for that long offers no benefits when consumed!

Which Coffee Beans Are Suitable for Cold Drip Coffee?

At this point, many people might think they should just choose a flavor they like—and that's absolutely correct! Just use your favorite coffee beans to make it. Due to the low-temperature extraction characteristics of cold brew and cold drip coffee, they can highlight the wine-like aromas and fruit fermentation notes in coffee, making them very suitable for flavor-profile coffee beans. FrontStreet Coffee believes that medium and medium-light roast beans that present rich floral and fruit aromas or fermentation notes are suitable for cold drip, such as Costa Rica Musician Series or Honduras whiskey barrel-treated coffee beans.

At FrontStreet Coffee, baristas typically use two different coffee beans blended together to make cold drip coffee to better highlight and balance the flavors of each cold drip coffee. The purpose is to emphasize certain flavor characteristics—one bean provides aroma, while another provides flavor. This time, FrontStreet Coffee will demonstrate making cold coffee using a blend of Costa Rica Mirasu Estate Geisha and Honduras whiskey barrel-fermented Sherry.

FrontStreet Coffee Brewing Parameters:

Coffee grounds: 60g (20g Geisha blend: 40g Sherry)

Coffee-to-water ratio: 1:10

1:1 ice-water mixture totaling 600ml

1. Place a circular filter paper at the bottom of the ground cup, moisten it with water to fit the cup wall, and add the ground 60g coffee grounds (FrontStreet Coffee uses China standard #20 sieve with 78% pass rate). Then shake to level the coffee surface, or use the weight of the tamper itself to lightly press the grounds layer to make the surface even.

2. Place a piece of filter paper over the coffee grounds layer. Because the tension of the filter paper allows water to distribute evenly across the surface of the grounds layer for extraction. Without filter paper, prolonged water dripping would create a pit in the coffee bed, affecting subsequent extraction.

3. First, evenly moisten the entire coffee grounds layer with water for "pre-soaking." This step is similar to the blooming in pour-over coffee and can improve extraction efficiency and consistency of the final product.

4. Add a 1:1 ice-water mixture to the upper pot, then adjust the valve to achieve a dripping speed of approximately 7 drops per 10 seconds. The cold drip apparatus should be placed in a cool, dry location and avoid human collisions.

5. Pour the finished coffee liquid into a sealed glass bottle and place it in the refrigerator to oxidize overnight, allowing the coffee flavors to meld together for a better taste.

For professional coffee knowledge exchange and more coffee bean information, please follow Coffee Workshop (WeChat public account: cafe_style)

For more specialty coffee beans, please add FrontStreet Coffee's private WeChat account: qjcoffeex

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473