Ice Drip and Cold Brew Coffee: A Complete Guide to Low-Temperature Brewing

Ice drip and cold brew coffee have become popular choices for iced coffee in summer, thanks to their smooth, refreshing taste. This article covers the Dutch origins of ice drip coffee and its spread to Japan and South Korea, then explains Front Street Coffee's production parameters for both methods, including grind size, coffee-to-water ratio, drip speed, and refrigeration time. It also recommends specialty beans suited to low-temperature extraction, such as Sherry, Yirgacheffe Gidding, Huakui, Butterfly Geisha, and Strawberry Candy.

The guide answers practical questions, like why cold brew should be refrigerated after making and why it is reliable finished within five days. It also details the coffee beans process for low-temperature brewing, noting that ice water extraction mainly draws out sweet and acidic notes while leaving heavier compounds behind. Because the process is slow, ice drip coffee often has more caffeine than hot-brewed coffee. The article suggests trying these two iced coffees if you want to avoid high-calorie drinks and enjoy a full-flavored cup.

In the height of summer, ice drip and cold brew, these two low-temperature extraction coffees, have become popular choices among iced coffees thanks to their refreshing, smooth, and full-flavored performance. This article sorts out the Dutch origins of ice drip coffee and its trend in Japan and South Korea, explains in detail Front Street Coffee's ice drip and cold brew production parameters, covering key points such as grind size, coffee-to-water ratio, drip speed, and refrigeration time, and recommends specialty beans suitable for low-temperature extraction, including Sherry, Yirgacheffe Gidding, Huakui, Butterfly Geisha, and Strawberry Candy. At the end, it also answers practical questions such as why cold brew should be refrigerated for further "aging" after it is made, and why it is recommended to finish it within 5 days.

As the hot summer arrives, being able to hold a cup of thoroughly icy coffee is surely the most delightful enjoyment in the hearts of many coffee lovers. If you want to avoid high-calorie drinks, care about mouthfeel and finish, and also enjoy trying new things, then this summer you might as well try two representative "goddess-level" iced coffees—ice drip coffee and cold brew (cold steeped) coffee. Compared with coffee extracted with hot water, these two low-temperature beverages have a unique and charming flavor, tasting refreshing and pleasant overall with a full flavor, especially satisfying in the scorching heat. Next, let's get to know ice drip and cold brew coffee together with Front Street Coffee!

Ice drip coffee also has another name—Dutch coffee. It is said that during the period when the Dutch ruled Indonesia, they planted large amounts of strongly bitter Robusta coffee there. In order to make this kind of extremely bitter bean drinkable in the tropics, they developed a device that brews coffee by slowly dripping cold water.

Unlike brewing with hot water, substances responsible for high body are difficult to release in the low-temperature environment of ice water, so ice water extraction mainly obtains the sour and sweet components in coffee; and because the whole process takes a long time, ice drip coffee actually has a higher caffeine content than hot-brewed coffee. Precisely because of this, this drink, which is refreshing and can quickly wake you up, is deeply loved by the Dutch.

Interestingly, although ice drip was born in the Netherlands, it is now almost nowhere to be seen in its birthplace; instead, Asia has stirred up an ice drip craze. In Japan, this kind of coffee has been passed down for hundreds of years, so it is also called "Kyoto coffee" and "Japanese-style slow-drip." The same is true in South Korea, where almost every cafe sells ice drip, and well-known ice drip equipment brands such as Tiamo and Hario mostly come from Japan and South Korea.

The Front Street Coffee store uses a Tiamo brand ice drip pot. When making ice drip, generally take 60 grams of coffee powder, grind it to a coarseness like fine granulated sugar (measured by the Chinese standard No. 20 sieve, with a passing rate of about 75%), aim to extract 600 grams of coffee liquid, with a coffee-to-liquid ratio of 1:10, and the drip water used is prepared by mixing ice cubes and water at 1:1.

First take a round filter paper and place it at the bottom of the powder cup, wet it with water so it fits tightly against the cup wall; then pour the ground 60 grams of coffee powder into the cup, shake gently to keep the surface of the powder layer flat, and then place another piece of filter paper on top of the powder layer. The tension of the filter paper allows water droplets to spread evenly over the entire powder layer to complete extraction. If this step is omitted, long dripping will punch a pit into the coffee bed.

After the filter paper is properly laid, first wet the entire powder layer with ice water. This step is similar to blooming in pour-over and helps improve extraction efficiency and consistency of the final product. Then pour the 1:1 mixture of ice cubes and water into the dripping bottle, and adjust the speed at which the water droplets fall; Front Street recommends controlling it at 6 drops every 10 seconds. After extraction is complete, pour the coffee liquid into a clean, water-free, oil-free, well-sealed bottle, put it in the refrigerator and let it slowly oxidize, and taste it after the flavor molecules of the ice drip coffee have been fully released.

Although ice drip is good, making it is quite troublesome, and throughout the process you need to check from time to time whether the ice water is still dripping. Ice cubes look very clean, with no impurities visible to the naked eye, but because the dripping speed is slow—on average only 6 drops every 10 seconds—completing one round of extraction usually takes 6 to 8 hours.

For this reason, the valve on the pot must be opened extremely small; even if only a trace of impurity is mixed in, it may clog the outlet. In addition, a full set of ice drip equipment is not cheap. In order to let people easily drink low-temperature extracted coffee at home, cold brew coffee came into being.

Ice drip relies on continuous dripping to extract coffee substances, while cold brew is much simpler: just prepare a clean, oil-free, sealable container, mix the ground coffee powder evenly with ice water or room-temperature water in an appropriate ratio, put it in the refrigerator for 8 to 12 hours, and finally filter out the coffee with a filtering tool. Because it uses immersion extraction, the resulting mouthfeel and flavor are much fuller.

On ordinary days, Front Street habitually uses a sealed cold brew pot to make iced coffee. The common parameters for cold brew are: take 60 grams of coffee powder, grind it to the coarseness of fine granulated sugar (measured by the Chinese standard No. 20 sieve, with a passing rate of about 75%), pour in 600 grams of room-temperature (or ice) water, with a coffee-to-water ratio of about 1:10, stir slightly so the coffee powder and water fully contact; then seal the container and place it in the refrigerator's cold storage compartment for 8 to 12 hours. When the time is up, filter out the coffee grounds completely, and a cup of iced coffee with full flavor and mouthfeel is done. When drinking, you can add 1 to 2 ice cubes according to personal taste and drink it after slight dilution.

One big advantage of low-temperature extraction is that it will not force out off-flavors and bitterness from the coffee beans, which is also why many people choose the Cold Brew method. In this way, it tastes fresh and slightly sweet, with sourness and bitterness noticeably suppressed, and the smoothness on the palate is also higher. But it also has a shortcoming: because the coffee powder and water are in contact for a long time, this kind of coffee has the highest caffeine content in the iced coffee lineup, so friends who are sensitive to caffeine should remember not to overindulge.

As mentioned above, when extracting coffee at low temperature, it is difficult to effectively extract substances responsible for body, so Front Street Coffee recommends choosing beans with prominent acidity, aroma, and flavor to make cold brew or ice drip, such as medium-light roasted coffee beans, or coffee beans processed by special processing methods, both of which are very suitable for cold extraction coffee.

What Front Street Coffee stores sell daily is ice drip coffee, and the beans used are usually: Front Street's Honduras Sherry coffee beans (vanilla cream, nuts, and fermented wine aroma flavors), Front Street's Ethiopia Yirgacheffe region Gidding coffee beans (citrus, honey, and green tea flavors), Front Street's Ethiopia Sidamo region Huakui coffee beans (complex berry juice, blending rose and black tea flavors), Front Street's Panama Butterfly (Geisha) coffee beans (white floral aroma, with citrus, honey, and green tea flavors), and Front Street's Costa Rica Strawberry Candy coffee beans (fermentation aroma, raisin, and strawberry hard candy flavors). Their commonality lies in rich aroma layers and prominent sweet-and-sour notes, making them very suitable for making refreshing iced coffee in summer.

After cold brew is made, is it still necessary to put it back in the refrigerator?

For the store's daily production, Front Street will seal the cold brew after filtering out the grounds and refrigerate it for 3 to 4 hours before taking it out for sale. Actually, everyone knows in their hearts that freshly made cold brew can be drunk directly, and the taste is not bad, so why add another chilling step?

For ice drip coffee, after extraction it should be transferred to a clean container and refrigerated overnight for better flavor—this is a lesson many experienced enthusiasts have long developed. Letting it stay in the refrigerator for a night is essentially sealed storage in a low-temperature environment, and can also be simply understood as "aging." There are two purposes: one is to control fermentation, and the other is to avoid spoilage.

A home refrigerator looks clean on the surface, but in reality it hides a large number of microorganisms that are difficult to distinguish with the naked eye, and if you are not careful, food may spoil and deteriorate. Therefore, if you want to ensure that the coffee is not contaminated by the outside world, the container used must have excellent sealing performance and must be cleaned thoroughly. Low-temperature storage is not only to inhibit the reproduction speed of certain bacteria, but also to allow the substances inside the coffee to undergo slow, controlled fermentation. This also explains why the longer ice drip is stored, the richer its fermented wine aroma becomes—in fact, it contains no alcohol, so everyone can drink it with peace of mind.

Compared with ice drip, cold brew lets water soak the coffee grounds all night, so the flavor is already relatively complete; at this point, putting the coffee liquid back into the refrigerator to chill for several hours is more about allowing the substances dissolved in the water to ferment further, thereby bringing a clearer and mellower taste.

Front Street has noticed that many friends who like convenience enjoy brewing a large pot of coffee at once and storing it in the refrigerator, pouring it out whenever they want to drink. In this way, if no mark is made, it is easy to forget exactly how many days this pot of coffee has been in the refrigerator and whether there is a problem of spoilage.

First of all, it should be understood that the fermentation process triggered by low-temperature extraction cannot be interrupted; refrigeration can only slow down the speed of coffee fermentation. As time passes, the substances dissolved in the water will continue to change, and eventually it will still spoil and deteriorate. In addition, every time the bottle cap is opened, the coffee liquid actually comes into contact with air, which not only causes aroma to dissipate, but may also bring bacteria into the container.

Overall, out of consideration for both flavor experience and health and safety, whether it is ice drip or cold brew, as long as it is coffee extracted at low temperature, Front Street's advice is to finish drinking it within 5 days from the day it is made.

If you want to exchange more professional coffee knowledge and get coffee bean information, welcome to follow Coffee Workshop (WeChat public account cafe_style).

If you want to buy more specialty coffee beans, you can add Front Street Coffee's personal WeChat, WeChat ID: qjcoffeex.

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