Is the Cold Brew Coffee Ratio 1:10 or 1:15? What's the Best Amount of Coffee Grounds and Water for Cold Brew?

The Essence of Cold Brew Coffee

Cold brew coffee's fundamental principle involves extracting small molecular substances that tend toward aroma and acidity, which are more easily released in cold water. This results in a light-bodied coffee with predominantly sweet and sour notes. Additionally, cold brew is accessible coffee making—unrestricted by equipment or location. At home, with just coffee grounds, a container, water, and a refrigerator, you can easily achieve caffeine freedom.

The Ratio Dilemma

However, attentive coffee enthusiasts have noticed a phenomenon: unlike pour-over coffee's nearly "unchanging 1:15" ratio, cold brew coffee ratios vary significantly. Some prefer 1:8, others advocate for 1:13, and some, like FrontStreet Coffee, habitually use 1:10. So how do different ratios affect the taste experience of cold brew?

How Ratio Affects Coffee Extraction

As a typical immersion extraction method, cold brew coffee involves prolonged contact between low-temperature water and coffee grounds in the same container, extracting flavors over time. When other parameters remain constant, a higher water proportion results in lower coffee concentration, milder flavor, and thinner body. Conversely, less water yields higher concentration, stronger flavor, and fuller body.

Therefore, to achieve balanced flavor and allow coffee to present its optimal characteristics, we must apply an appropriate coffee-to-water ratio.

Key Variables in Cold Brew Preparation

How long should cold brew steep? How fine should the coffee be ground?

We know that various parameters in any extraction method are interrelated. For cold brew, the coffee-to-water ratio isn't the sole determinant of flavor. We must also consider grind size, steeping time, water quality, and most critically, the coffee beans themselves.

Although low-temperature extraction reduces the emergence of bitter substances, it's not completely eliminated. To pursue deliciousness, coffee grounds for cold brew shouldn't be too fine, nor should they steep too long. For the former, we recommend controlling the sieve pass rate at approximately 80-85% using a 0.85mm standard sieve—visually similar to granulated sugar particles. For the latter, it's best to keep steeping time between 6-16 hours, ensuring sufficient contact between grounds and water while avoiding over-extraction that produces negative flavors.

FrontStreet Coffee emphasizes water quality not only because it's the extraction medium but also because it's the most easily overlooked parameter among all variables. For instance, FrontStreet Coffee frequently receives inquiries from customers who have purchased our coffee beans and followed the parameters provided in articles to make cold brew, yet the flavor doesn't meet expectations. After eliminating various "culprits," they discover the issue stems from that colorless, tasteless "water." Friends with similar frustrations can refer to FrontStreet Coffee's past comparative experiment: "Making Cold Brew with Different Water—The Difference is Surprising!" We won't elaborate further here.

Coffee Bean Selection

For coffee bean selection, FrontStreet Coffee uses Kenya AA as our experimental demonstration. It employs the K72 washed processing method with SL28 and SL34 varieties. Both SL28 and SL34 are varieties selected through multiple breeding cycles. SL28 belongs to the Bourbon genetic group, carrying the bright acidity and rich acidity of original Bourbon. SL34's lineage is closer to Typica genetics, with milder acidity.

When made into iced coffee, Kenya AA offers a sensation of dark berries enveloping the palate, accompanied by abundant cherry tomato aroma. When served chilled, it's exceptionally refreshing, making it a preferred bean choice for many cold brew enthusiasts.

Comparing Different Ratios

How do different coffee-to-water ratios affect cold brew flavor?

Since cold brew always occurs in a 0-10°C environment with very low extraction efficiency, and coffee grounds remain relatively static with no external force applied during the process, the rate at which coffee grounds dissolve flavor compounds is quite limited. To make experimental results clearer, FrontStreet Coffee established four common ratios: 1:8, 1:10, 1:12, and 1:15, keeping all other parameters constant.

The preparation process was identical: coffee grounds and water were poured sequentially into containers, then stirred, sealed, and placed in the refrigerator. When time elapsed, we removed them for filtration (stirring once midway is acceptable).

Experimental Parameters

Coffee beans: Kenya Washed AA

Coffee amount: 18g

Steeping time: 6 hours

Grind size: Fine sugar/80% pass rate through China #20 standard sieve (EK43s setting 9.5)

Coffee-to-water ratios: 1:8, 1:10, 1:12, 1:15

Corresponding water amounts: 144g, 180g, 216g, 270g

Tasting Results

1:8 ratio: The coffee liquid showed the darkest color, with the most intense flavor and acidity. The body even felt slightly salty, with minimal berry notes and a bitter aftertaste.

1:10 ratio: The coffee liquid emitted a fresh sugarcane aroma, with flavors of red plum, berries, and pear tea. The body was slightly concentrated, with high acidity and不明显 sweetness.

1:12 ratio: This cold brew had the clearest body, with flavors of cherry tomatoes, red plums, dark plum juice, sugarcane, and a preserved plum candy aftertaste. The concentration was moderate, with balanced sweet and sour notes.

1:15 ratio: The coffee liquid had the lightest color and thin body, with only subtle black plum and berry acidity. The taste was mild but almost entirely lacked bitterness.

Analysis and FrontStreet Coffee's Approach

From the above comparison, it's evident that the 1:8 ratio, due to less water, doesn't provide enough space for coffee flavors to develop and easily exhibits thick, bitter characteristics. Conversely, the 1:15 ratio, with more water, over-dilutes soluble compounds, resulting in insufficient richness and naturally bland taste.

Between the 1:10 and 1:12 groups, the 1:12 ratio clearly produced cold brew with the best flavor and body when consumed directly. So why does FrontStreet Coffee prioritize 1:10 in many articles and daily preparations?

FrontStreet Coffee considers two key factors for cold brew service.

First, to maintain cold brew's chilled temperature, we not only use chilled glasses but also add 1-2 large ice cubes. This way, even if the coffee dilutes slightly, the flavor won't change significantly. Second, since customers have different taste preferences—some preferring lighter, others stronger—the initial serving with ice cubes offers full-bodied coffee. As the ice gradually melts into water, the coffee becomes lighter. Therefore, using higher concentration cold brew with ice satisfies both "strong flavor" and "light flavor" preferences.

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473