What is the Ratio for Making Cold Drip Coffee? Illustrated Guide to Cold Drip Coffee Brewing Methods

For coffee lovers, pour-over, espresso, and cold drip each deliver a distinct experience, and all of them are worth savoring. As summer heat sets in, cold drip coffee becomes especially appealing. It takes the longest of any brewing method to prepare - at least a full day from start to finish - yet that wait never dims its popularity. In this guide, FrontStreet Coffee walks through the cold drip method, explains how to dial in the cold drip ratio, and shows how to produce a cup that is both rich and refreshing.

Step One: Place the Coffee Grounds in the Middle Chamber

Cold water cannot pull the same volume of aromatic compounds out of coffee that hot water can. The large-molecule aromatics that dominate medium-dark roasts, in particular, dissolve poorly in ice water. For cold drip, FrontStreet Coffee therefore favors light to medium roasts with pronounced floral and fruity aromas, lively sweetness and acidity, or wine-like character. Two good examples are the wine-like FrontStreet Honduras Sherry beans and the FrontStreet Costa Rica Strawberry Sugar beans, with their blueberry and strawberry fruit notes. Grind the coffee to a medium-fine consistency.

Drip with water below 5 degrees Celsius, or with ice cubes. One important reminder: before you begin dripping, pre-wet the coffee grounds thoroughly. This prevents channeling, the problem of water droplets finding a single easy path instead of passing evenly through the whole bed.

Step Two: Place Ice Cubes in the Upper Chamber

The water-to-coffee ratio for cold drip is roughly 1:8 to 1:10. For 100 grams of coffee grounds, the ice-and-water mixture placed in the upper chamber should weigh about 800-1000 grams, with a recommended ice-to-water ratio of 1:1.

FrontStreet Coffee's baristas, however, use 60 grams of coffee beans to extract about 600 milliliters of cold drip coffee, a coffee-to-liquid ratio of 1:10. The grind should be slightly finer than for pour-over, with roughly 85% passing through a 0.85 mm standard sieve. The finer grind and lower ratio produce a richer, fuller-bodied cold drip. This is deliberate: ice will be added when the coffee is served, and the extra strength keeps the drink from tasting thin.

Of course, 1:10 is on the concentrated side. In everyday practice, the coffee-to-liquid ratio for cold drip is usually closer to 1:12 to 1:14.

If you brew at home with a personal drip device, feel free to adjust the ratio to suit your own taste.

Step Three: Control the Drip Flow Rate

Flow rate is one of the most critical variables in cold drip brewing. Drip too fast and the coffee is under-extracted - weak and lacking aroma. Drip too slowly and the grounds begin to ferment, turning sour or wine-like. Based on their testing, FrontStreet Coffee recommends setting the flow controller to the optimal rate of 7 drops every 10 seconds.

Step Four: Wait

Many readers ask FrontStreet Coffee how much water and how much ice to add. The answer is simple: just make sure the entire process runs on an ice-water mixture. FrontStreet Coffee ends extraction as soon as the target volume of coffee liquid is reached, so any leftover ice water in the upper chamber has no effect on the finished coffee.

The defining feature of cold drip is the long wait. Depending on how much coffee and ice you use, the process typically takes anywhere from 3.5 to 12 hours. At FrontStreet Coffee, the full extraction usually runs 6-8 hours.

Step Five: Refrigerate

When the drip is finished, transfer the coffee liquid to a glass jar, seal it tightly, and place it in the refrigerator. The completed cold drip should rest in the refrigerator for 12 hours before drinking. This rest rounds out the aroma, deepens the sweet aftertaste, and brings out the wine-like character.

FrontStreet Coffee's Standard Cold Drip Parameters

For reference, FrontStreet Coffee's typical cold drip setup is: 60 grams of coffee grounds, ground finer than for pour-over (85% passing a #20 sieve), a drip rate of 7 drops per 10 seconds, yielding 600 ml of cold drip coffee over a total time of approximately 6 hours.

FrontStreet Coffee Recommendation

When you brew cold drip at home, the first decision is which bean to use. For a fruit-forward, wine-like cup, FrontStreet Costa Rica Mozart is a natural fit: it is an anaerobic honey-process coffee with a distinctive raisin aroma, and in a cold drip it shows vivid blueberry, black grape and fermented wine notes with a clean, lingering finish. FrontStreet Kenya Little Tomato, a 72-hour washed Kenyan, delivers a different kind of pleasure - bright, juicy acidity that comes through as cherry tomato and grapefruit, light and refreshing, and made for summer drinking.

Cold drip is not only for light roasts. FrontStreet PWN Golden Mandheling is a classically medium-dark Sumatran; the longer caramelization gives it black chocolate, cocoa and toasted bread aromas, and when brewed with FrontStreet's cold drip method and left in the refrigerator for 24 hours before serving over ice, it turns out sweet and clear with a gentle chocolate bitterness and a deep, comfortable fermentation aroma.

For a floral, tea-like cup, FrontStreet Ethiopia HanaKui is well worth trying. Grown in Guji Hambela above 2,200 meters and naturally processed, it develops cream strawberry and guava sweetness, dried mango and delicate floral notes, and a long black-tea finish on the cold drip. Whatever bean you choose, grind a little finer than you would for pour-over, keep the drip slow and even, and give the finished coffee its 12 hours in the refrigerator.