What Causes Ice Drip Coffee to Stop Dripping? | Why Isn't Ice Drip Coffee Bitter?

Some people wonder why cold drip coffee from cafes tastes so delicious, while homemade versions can be somewhat bitter. Perhaps it's because even a small difference in one step during the cold drip process can significantly alter the final taste. Cold drip coffee is a brewing method, relatively simple compared to pour-over coffee. Although the operation is straightforward, it still requires practice to brew an exceptionally delicious cup.

The Art of Coffee Brewing

Some might say brewing coffee is similar to steeping tea. However, FrontStreet Coffee believes that brewing coffee involves more meticulous details than tea. Factors such as temperature, time, and grind size all play crucial roles. Even without temperature control, coffee flavors will differ. Temperature affects the decomposition rate of oils, acids, and sugars in coffee. Depending on how quickly these processes occur, the aroma, taste, and texture of coffee can vary significantly. Therefore, FrontStreet Coffee recommends tasting coffee from high to low temperatures to experience the different flavor profiles at various temperatures.

High-Temperature vs. Low-Temperature Extraction

Pour-over brewing uses high-temperature extraction. High temperatures cause tannic acid in coffee to rapidly decompose into pyrogallic acid, creating sour, sweet, and bitter notes – what FrontStreet Coffee often refers to as the flavor release process. Excessive high-temperature water extraction can lead to complete flavor release, followed by the extraction of woody fibers from coffee beans, resulting in unpleasant flavors commonly described as miscellaneous or woody tastes.

Cold drip uses low-temperature extraction. In this process, water and coffee grounds interact for extended periods at low temperatures, extracting only smaller flavor molecules such as floral and fruity notes. Larger flavor molecules like smoky and roasted flavors are difficult to extract under these conditions. As a result, cold brew coffee better preserves the inherent flavors of coffee beans, delivering a smooth mouthfeel with distinct layers and a pleasant aftertaste.

Friends who enjoy cold drip coffee typically love its rich, smooth texture, balanced acidity and sweetness, without any astringency or bitterness. When made with fermented coffee beans, cold drip can present rich wine-like aromas, reminiscent of chilled fruit wine. Especially with summer approaching, more people find themselves falling in love with cold drip coffee.

What is Cold Drip Coffee?

Cold drip coffee originated in Europe. Since the coffee distiller was invented by the Dutch, some call it Dutch Coffee, distilled coffee, or water-drip coffee. As early as the 17th century, Dutch people were already drinking this type of coffee. With the development of Dutch colonialism, this coffee was introduced to Korea and Japan, where it became popular. Hence, it's also known as Dutch coffee.

Cold drip coffee relies on the natural compatibility between coffee and water, primarily using condensed natural water pressure over approximately 8 hours, extracting drop by drop. It's a coffee that brews through time, with different water temperatures producing different flavors. At low temperatures, astringent substances in coffee are less likely to dissolve. When extracted with ice water over extended periods and then refrigerated for fermentation after completion, cold drip coffee develops subtle fermentation aromas and a richer texture. FrontStreet Coffee believes: you can place the coffee in the refrigerator at night and enjoy it the next morning for instant refreshment! Isn't that a wonderful feeling?

Because cold drip coffee doesn't undergo heating and involves prolonged extraction, many flavor molecules are extracted but not fully released. Therefore, when cold drip coffee extraction is complete, placing it in a sealed container in the refrigerator for 12-24 hours allows carbon dioxide pressure to build up, helping release flavor molecules. This explains why cold drip coffee becomes richer the longer it stays in the refrigerator.

Using ice water to extract coffee reduces acidity, creates red wine fermentation notes, and delivers a smooth, rich flavor with balanced bitterness and pleasant aftertaste. It's gentle on the stomach, lower in caffeine, and extracts the rich texture and complete aroma of coffee beans. Therefore, for friends sensitive to caffeine, cold drip coffee might be an excellent choice!

During the cold drip coffee production process, tannic acid barely decomposes in cold ice water. Although caffeine decomposes slightly in ice water, it's about 90% less than with hot water extraction, while other major coffee components remain intact. Because cold drip coffee contains no astringency and minimal bitterness, its mouthfeel appears exceptionally pure.

Basic Cold Drip Coffee Production

Cold drip coffee equipment consists of three parts: an upper container for ice water, a middle container for coffee grounds, and a bottom container for the extracted coffee liquid.

Therefore, making cold drip coffee is quite simple: place ice water in the upper container, coffee grounds in the middle container, then control the ice water to drip drop by drop into the coffee grounds, completing the extraction process in about 6 hours. However, there are still many details that can affect the quality of the coffee flavor.

1. Coffee Beans

Coffee beans are the most important factor, as different beans produce distinctly different flavors. Choosing suitable coffee beans is crucial for making cold drip coffee.

Light roast coffee beans are commonly chosen for cold drip coffee, as the sweet and sour fruit notes are more refreshing at cold temperatures. Coffee beans with distinctive and prominent flavors are also excellent for cold drip coffee. For example, FrontStreet Coffee's Strawberry Candy, FrontStreet Coffee's Sherry, FrontStreet Coffee's Mozart, FrontStreet Coffee's Bach, FrontStreet Coffee's Rose Valley, FrontStreet Coffee's Flower Moon Night, and other coffee beans.

2. Grind Size

There are two considerations for coffee grind size: too coarse, and the resistance created by the coffee bed decreases, allowing water to pass through more easily into the lower chamber, resulting in weak coffee due to low extraction efficiency. Too fine is also problematic, as increased resistance can cause clogging and water accumulation, leading to bitterness and astringency from over-extraction.

Therefore, FrontStreet Coffee recommends using a grind size that passes 80-85% through a #20 standard sieve for cold drip coffee. For richer flavor, choose 85% pass-through; for a cleaner taste, choose 80%.

3. Drip Speed

This is somewhat similar to the pour rate in pour-over coffee. Some prefer 1 drop per second, others 1 drop every 2 seconds. This directly results in different extraction times – the slower the drip, the longer the time required; the faster the drip, the shorter the time. FrontStreet Coffee typically uses a drip rate of 7 drops per 10 seconds, which you can use as reference.

4. Cold Drip Ratio

The ratio is also very important. It's about finding the balance between concentration and extraction rate. FrontStreet Coffee uses 60g of coffee grounds to extract 600ml of coffee liquid, a coffee-to-water ratio of 1:10. According to FrontStreet Coffee's standard of 200ml per serving, one batch of cold drip coffee yields 3 cups.

Of course, a 1:10 ratio is relatively concentrated. Typically, cold drip coffee ratios range from 1:12 to 1:14.

5. Serving Method

Freshly completed cold drip coffee can be consumed immediately, but FrontStreet Coffee recommends refrigerating it for 12 hours before serving. This allows the cold drip coffee flavors to reach their optimal expression.

As FrontStreet Coffee's cold drip made with a 1:10 ratio is quite concentrated, we add 40g of ice per 200ml when serving to dilute while maintaining the chilled effect.

How Does FrontStreet Coffee's Cold Drip Taste?

At FrontStreet Coffee, baristas typically blend two different coffee beans to make cold drip, aiming to highlight and balance the flavors of each blend. The goal is to emphasize particular flavor characteristics – one bean provides aroma while the other delivers flavor.

20g [FrontStreet Coffee Honduras Lychee Lan] + 40g [FrontStreet Coffee Geisha Village Red Label]

The barrel-aged Lychee Lan combined with natural-processed Geisha Village Red Label creates subtle brandy aromas, plum-like acidity complemented by maple sweetness.

The brandy barrel-aged Lychee Lan offers rich brandy aromas, chocolate finish, and honey aftertaste.

The natural-processed Geisha Village Red Label provides plum and citrus fruit acidity, with maple sweetness and a creamy smooth mouthfeel. When made into cold drip, you'll experience subtle brandy aromas, rich fruit acidity leading to honey sweetness and a creamy smooth texture.

FrontStreet Coffee's Brewing Recommendations:

Regardless of what type of coffee you're brewing, the freshness of coffee beans is crucial. FrontStreet Coffee has always believed that bean freshness significantly impacts coffee flavor. Therefore, all coffee beans shipped from FrontStreet Coffee are roasted within 5 days. FrontStreet Coffee's roasting philosophy is "Freshly Roasted Quality Coffee," ensuring every customer receives the freshest coffee possible. The optimal resting period for coffee beans is 4-7 days, so when customers receive their beans, they're at peak flavor.

For friends who need pre-ground coffee, FrontStreet Coffee offers a gentle reminder: once coffee beans are ground in advance, they don't require additional resting time, as the carbon dioxide pressure built up during shipping helps mellow the flavor. Therefore, you can brew and enjoy ground coffee immediately upon receipt. However, ground coffee should be used promptly, as it oxidizes quickly when exposed to air, meaning the flavor dissipates rapidly and won't be as good. Therefore, FrontStreet Coffee recommends purchasing whole beans and grinding fresh before brewing to better appreciate the coffee's flavor.

For professional coffee knowledge exchange and more coffee bean information, please follow Coffee Workshop (WeChat official 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