Can Ice Water Be Used to Brew Coffee? What's the Optimal Temperature for Pour-Over Coffee? How Fine Should the Grind Be?

Why Iced Pour-Over Coffee Isn't Made with Cold Water

Customers often ask FrontStreet Coffee this question when making iced pour-over coffee: "Why don't we use cold water for iced pour-over coffee? Must we use hot water?"

It's not surprising that this question comes up, because for those who are new to the coffee world or have just recently begun exploring it, iced pour-over coffee can indeed lead to such misunderstandings. Additionally, many bloggers share techniques for brewing delicious coffee with cold water. This brings us to the real question: Can you actually brew delicious coffee with cold water?

The Cold Water Experiment

Technically speaking, cold water can be used to brew coffee! However, if we add the premise of it being "delicious," then based on FrontStreet Coffee's taste preferences, we believe that using only cold water cannot produce a delicious cup of coffee! Why? You'll understand when you see the cup of coffee that FrontStreet Coffee brewed with cold water below.

Water temperature, grind size, time, stirring intensity, and ratio are the main factors that affect extraction efficiency in pour-over coffee. FrontStreet Coffee often emphasizes that brewing a delicious cup of coffee requires the right balance between different parameters. The extraction efficiency of cold water is extremely low. If we want to extract coffee flavors using cold water, theoretically we need to increase the extraction efficiency of other parameters. For example, using the finest grind, stronger stirring, and longer extraction time. Therefore, FrontStreet Coffee will use this extreme combination to brew a pour-over coffee with cold water!

Experiment Parameters

For this brewing, FrontStreet Coffee used beans from their menu: FrontStreet Coffee's Boundary Manor · Sidra. Under normal iced brewing conditions, it displays rich grape juice, passion fruit, apricot, and subtle red wine flavor notes, with a pleasant sweet and sour taste, much like a glass of grape juice with wine-like aromas. But what kind of flavors will this unconventional iced brewing method produce? Let's wait and see! The extraction parameters are as follows:

Coffee amount used: 15g
Brewing water temperature: 4°C
Coffee-to-water ratio: 1:10
Grind level: Setting 1 on the Q18 espresso grinder - flour-like particles
Brewing method: Stirring method

Since we don't recommend trying this nor is it necessary, FrontStreet Coffee will skip the complex step introduction. To briefly summarize the process, the water was divided into three equal portions for pouring, with manual stirring throughout each portion.

Results and Comparison

Total time: 5 minutes. In the picture below, the right side shows a normally brewed pour-over, while the left side shows the pour-over brewed with cold water.

Just from the color brightness, we can see that the coffee on the left won't have a high concentration. And indeed, the taste confirms this - similar to "Making Cold Brew in One Minute with Cold Water" that FrontStreet Coffee shared a while ago, it only has a faint coffee aroma, weak coffee flavor, and overall tastes like coffee-flavored water.

From the above experiment, you can see that even though FrontStreet Coffee used the finest grind, stirred throughout the entire process, and the extraction time was as long as five minutes, we still couldn't dissolve the flavor compounds from the coffee.

The Science Behind Cold Water Extraction

This is expected because the extraction efficiency of cold water is too low. It cannot quickly soften the coffee fibers to penetrate internally, naturally making it impossible to quickly dissolve the flavor compounds in the coffee. Even when FrontStreet Coffee used pressure-assisted brewing with higher extraction efficiency, we still couldn't extract the coffee's flavor in a short time. Therefore, FrontStreet Coffee doesn't recommend using lower temperature water for short-term coffee extraction, such as pour-over or espresso, because cold water's extraction efficiency is too low to quickly dissolve large amounts of flavor compounds like hot water can.

Recommended Cold Water Methods

If we only have cold water available, we can make coffee through methods like cold brew or cold drip. These extraction methods use sufficient time to allow cold water to penetrate into the coffee beans and extract the hidden flavor compounds.

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473