How Long Can Cold Brew Coffee Last? How to Make Cold Drip and Cold Brew Coffee? What Are the Extraction Parameters?

Why Everyone Loves Making Cold Brew at Home?

As the saying goes, "No cold brew, no summer!" Recently, among the various brewing questions FrontStreet Coffee has collected, besides inquiries about suitable coffee beans for cold brew, the most concern has been about operational details. For example, should cold brew be refrigerated again after filtering? How many days can homemade cold brew typically be stored? Today, FrontStreet Coffee is here to thoroughly analyze these questions for everyone.

The answer is obvious—it's all about convenience. Compared to other fresh-ground coffee preparations, cold brew only requires grinding coffee beans and adding water to steep the night before, sealing it properly, and placing it in the refrigerator. The next morning, you simply remove the filter and can pour the coffee into a cup to take to work. It can be said to be one of the most hassle-free coffee methods, and also one that we can easily replicate at home to achieve the same quality as coffee shop versions.

Secondly, when we choose our favorite coffee beans for preparation, the low-temperature fermentation process of cold brewing brings unique flavors. For example, cold brew made by FrontStreet Coffee using Kenya Assalia offers flavors of plum juice and cherry, accompanied by a rich mouthfeel with subtle fermentation notes—characteristics that ice pour-over cannot provide.

What's the Difference Between High-Temperature and Low-Temperature Extraction?

Coffee enthusiasts all know that a cup of coffee extracted with hot water has the most pleasant aroma when freshly made, such as pour-over, espresso, or siphon coffee. However, once left at room temperature for an hour or so, the volatile aromas in coffee significantly diminish with the temperature drop, sometimes disappearing completely. This is why baristas always diligently remind us: drink it while it's hot!

Conversely, cold brew and cold drip, which use cold water and require several hours of steeping or slow dripping, need a certain period of settling and "maturation" to achieve ideal flavor and mouthfeel. Because these cold-prepared coffees maintain all soluble flavor substances in a low-temperature environment throughout, they are less affected by temperature changes and won't quickly volatilize into the air. Therefore, as long as storage conditions are appropriate, they offer a longer shelf life.

Should Cold Brew Be Refrigerated Again After Brewing?

For cold brew typically served at their shop, FrontStreet Coffee seals and refrigerates it for 3-4 hours after filtering before selling. In fact, we know that freshly made cold brew can be consumed directly and tastes quite good. So why refrigerate it again?

Cold drip coffee should be transferred to a clean container and refrigerated overnight after extraction for better taste—this is a habit many experienced coffee lovers have already developed. Leaving it in the refrigerator overnight achieves sealed storage in a low-temperature environment, which we can simply understand as "maturation," with two purposes: controlling fermentation and preventing spoilage.

Although home refrigerators may appear clean on the surface, they actually contain many microorganisms that are difficult to detect with the naked eye. If not careful, this can lead to food spoilage or deterioration. Therefore, to ensure coffee isn't contaminated by external factors, the containers we use must have good sealing performance and be thoroughly cleaned. Low-temperature storage not only inhibits the reproduction rate of certain bacterial colonies but also allows substances within the coffee to undergo a slow, controlled fermentation process. This also explains why the longer cold drip is stored, the more intense its fermented flavors become.

Compared to cold drip extracted at room temperature, cold brew—where water soaks coffee grounds all night—already possesses relatively complete flavors. At this point, rechilling the coffee liquid for several hours primarily aims to further ferment the water-soluble substances, bringing a clearer and mellower coffee mouthfeel.

How Many Days Can Refrigerated Cold Brew Be Stored?

FrontStreet Coffee has noticed that many convenience-seeking enthusiasts will brew a large pot of coffee at once and store it in the refrigerator, pouring it out whenever they want to drink. This leads to situations where, if not properly marked, it's easy to forget how many days the coffee has been in the refrigerator, raising concerns about potential spoilage.

First, the fermentation process of low-temperature extraction is uninterrupted—refrigeration only slows down the coffee's fermentation rate. As time progresses, substances dissolved in water continuously change, eventually leading to spoilage. Additionally, each time we open the bottle, the coffee liquid comes into contact with air. This not only causes aroma dissipation but may also introduce bacteria into the container.

To understand how storage days affect cold brew flavor, FrontStreet Coffee conducted tests on two batches of cold brew, tasting them when freshly made, after 1-2 days of refrigeration, 3-4 days, 5-6 days, and 7-8 days. The final discovery was that coffee mouthfeel was best within the 1-4 day refrigeration period.

Storage Days/Coffee Beans

Litchi Orchid

Washed Mariposa

Freshly Made: Lychee wood, fermented wine aroma / Citrus, tea-like sensation

Refrigerated 1-2 Days: Fresh melon fragrance, chocolate, brandy aroma / Honey, raspberry, grapefruit, refreshing and bright

3-4 Days: Chocolate liqueur, maple syrup, honey / Light floral notes, blueberry, oolong tea, slight fermentation

5-6 Days: Almond, chocolate, intense wine sensation, diminished aroma / Berry acidity, stronger tea sensation

7-8 Days: Only wine sensation remains, lacking aroma / Stimulating fruit acidity, heavy mouthfeel

Generally, considering both flavor experience and health safety, whether for cold drip or cold brew, FrontStreet Coffee recommends everyone to finish it within 5 days (counting from the production day) for any extraction method performed in low-temperature environments.

If you follow the method described in FrontStreet Coffee's previous articles, using warm water to quickly make cold brew, the optimal tasting period will be shorter. Because higher water temperature leads to greater release of flavor compounds, compared to cold brew made with room temperature water, the warm water version is more likely to breed microorganisms in the refrigerator. Therefore, FrontStreet Coffee believes it's best to consume it within 2 days to avoid potential digestive discomfort.

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473