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What are the key points for making cold brew coffee? What's the difference between cold brew and iced drip coffee? Why does the extraction time need to be 8 hours?

Published: 2026-01-27 Author: FrontStreet Coffee

Last Updated: 2026/01/27, Even though the arrival of the Beginning of Autumn has brought some coolness to the scorching Guangdong province, it's just a little relief! People are still being roasted by the scorching high temperature of 37°C! Because of this, refreshing and rich cold brew coffee remains the favorite of most people! But many friends who make it at home find that their own cold brew coffee never tastes as good as...

Why Your Cold Brew Coffee Tastes Watery: Common Mistakes to Avoid

Even though the beginning of autumn has brought some relief from the heat to Guangdong, it's only a slight relief! Most people are still enduring the scorching 37°C temperatures! Because of this, refreshing and rich cold brew coffee remains the favorite choice for many people!

However, many people who make cold brew at home discover that their homemade cold brew coffee never tastes as rich as what they drink in coffee shops. Similar to hot pour-over coffee with ice added, it has flavor but tastes quite weak. As a result, FrontStreet Coffee has received many private messages about cold brew coffee.

"Cold brew coffee" refers to coffee extracted with cold water. Therefore, both drip-style ice drip coffee and immersion-style cold brew coffee belong to the family of cold brew coffee. Normally, when we taste a cup of coffee that is very weak in flavor, it means the coffee's concentration isn't high enough! There are only two reasons for insufficient coffee concentration: either the extraction is insufficient, or the coffee has been over-diluted! Compared to pour-over coffee, these "accidents" happen more frequently with cold brew coffee. The reason is quite simple: because most friends apply the brewing principles of pour-over coffee to make cold brew coffee, which results in weak-tasting extracted coffee. So today, FrontStreet Coffee will share what exactly causes weak coffee flavor, which everyone can reference to avoid these pitfalls~~

1. Dilution from Low Coffee-to-Water Ratio

Many friends use the same coffee-to-water ratio for making cold brew coffee as they do for hot pour-over coffee, thinking that since it takes so long, the extraction will naturally be more comprehensive. This is one of the main culprits for insufficient coffee concentration: too much water.

The reason is quite simple: because ice water's extraction efficiency is not high, it needs a long extraction time to achieve a suitable coffee concentration. However, even so, it cannot completely extract all substances from the coffee like hot brewing does. This results in insufficient coffee concentration and weak flavor when using the same ratio. Therefore, we need to increase the coffee-to-water ratio when making cold brew coffee, using less water to extract coffee in order to achieve sufficient coffee concentration! Generally, FrontStreet Coffee uses a 1:10 to 1:12 coffee-to-water ratio for extraction. Use 1:10 if you want it stronger, and you can always choose to add ice/water for dilution if it's too strong later; if you don't want to add ice later and want to drink it directly, choose 1:12 for a slightly lighter taste~

2. Grind Too Coarse or Too Fine, Leading to Low Extraction Efficiency

As everyone knows, the coarseness of coffee grinding determines particle size. When the grind is coarser, the surface area of the coffee grounds becomes smaller, thus reducing extraction efficiency. So most people will adjust the grind very fine when making cold brew coffee, trying to help water better extract substances from the coffee grounds. But actually, doing this has a negative effect when making cold brew (immersion) coffee!

Because during long periods of resting, overly fine particles will clump together and form lumps, and with continuous accumulation, they create obstacles to water extraction! For details, you can refer to this article "Why Does Finer Grind Lead to Lower Extraction Rate?" for a detailed explanation! Therefore, FrontStreet Coffee recommends using a grind size similar to iced pour-over when making cold brew, which won't cause insufficient extraction due to being too coarse, nor will it cause clumping due to being too fine!

If you're unable to change the grind size, you can use filter bags for separate soaking, which is an excellent method! Not only is extraction efficiency higher, but you also don't need to filter coffee grounds. (There's also a related article on this topic that you can click to read: "Cold Brew with Tea Bags?")

3. Insufficient Steeping Time, Cold Water Fails to Extract Fully

Because the water temperature is lower, as mentioned earlier, it needs more time for extraction. Generally speaking, we control the extraction time for both cold brew and ice drip! For example, cold brew time is controlled to be over eight hours, while ice drip adjusts the water dripping speed to one drop every two seconds to extend the extraction time. Only in this way can cold water have sufficient time for extraction!

Notably, besides extraction time, ice drip also requires a certain "maturation" time. Through resting, the coffee undergoes fermentation, which brings extremely rich aromas and flavors to ice drip, making it even more outstanding when tasted! The main reasons for weak cold brew coffee are the three points above. Everyone can check which ones apply to their situation~ If there are other factors, everyone is welcome to message FrontStreet Coffee privately, and we'll definitely include them in our next sharing!

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