Cold Brew Coffee Storage Time | Cold Brew Coffee Too Sour Adjustment Techniques | Cold Brew Coffee Tutorial

In a previous article titled "Why isn't my homemade cold brew strong enough?" FrontStreet Coffee mentioned that the strength of cold brew coffee depends not only on the grind size and coffee-to-water ratio, but also on the steeping time. Since that article didn't detail the steeping time, some friends have sent private messages asking how long cold brew coffee should be steeped.

How Long Should Cold Brew Coffee Be Steeped?

Cold brew is an immersion extraction method, which allows us to control its extraction time freely. Similar to hot coffee brewing, the longer the extraction time, the more completely the flavor compounds are released. The difference is that cold brew uses cold water for extraction. Compared with hot coffee brewing, the extraction capacity of water is not as high, which is why cold brew requires a longer steeping time. It is also why cold brew is less likely to become over-extracted.

However, just because it is less likely to be over-extracted doesn't mean it won't happen. Based on several experiments conducted by FrontStreet Coffee, when coffee is steeped for more than 24 hours, the extracted coffee develops a distinct woody taste. If steeped for less than 8 hours, it becomes watery coffee. FrontStreet Coffee therefore generally recommends controlling the cold brew time between 8 and 24 hours.

Even though the extraction efficiency is relatively low, the range between 8 and 24 hours is quite large, and coffee will continuously release flavor compounds during this period. So within this range, which steeping time yields the best-tasting coffee? Let's look at the experiment FrontStreet Coffee has prepared below.

Cold Brew Experiment

FrontStreet Coffee started steeping three separate batches of cold brew yesterday at 7 AM, 3 PM, and 11 PM respectively, then filtered them this morning at 7 AM to see what differences exist among the three cold brews with different steeping times.

In this experiment, FrontStreet Coffee used Ethiopian FrontStreet Santa Wani, an anaerobically processed coffee bean with full fruit flavors. All extraction parameters were fixed except for time, as follows:

Coffee amount used: 20g; Coffee-to-water ratio: 1:10; Grind setting: EK43 at 9.5, fine sugar grind, with 85% passing through a #20 sieve (same grind as hot pour-over)

The production process was identical for all batches: coffee grounds and water were poured into the container in sequence, then stirred, sealed, and placed in the refrigerator for the set time. When the time was up, we took them out and filtered them.

Then we could begin tasting. The results were as follows:

8-hour steeping: This cold brew had brighter acidity, a relatively light overall mouthfeel, moderate concentration, and was easy to drink.

16-hour steeping: This cold brew had more rounded acidity, a fuller juice-like sensation, and was slightly more concentrated than the 8-hour version.

24-hour steeping: This cold brew's acidity was less prominent, with more balanced flavors and a rich, full-bodied texture. Overall it was more intense.

As you can see, cold brews steeped for different times exhibit different characteristics, and we can decide on the steeping time based on our preferences. It is also influenced by other parameters, so everyone can be flexible. After all, the advantage of immersion extraction is its higher fault tolerance. With these parameters, FrontStreet Coffee's favorite is the 16-hour steeping, because light-roast coffee steeped this way develops a wonderfully full juice-like sensation, and secondly, you don't need to worry too much about the time~~

However, everyone should note that storage requirements are quite important. Whether it is cold brew or iced drip coffee, after filtering we must find a clean, sealable bottle for low-temperature refrigeration (all three conditions must be met). Otherwise the coffee can easily spoil, which can affect your health.

Naturally, the storage time should be as short as possible, depending on how frequently you consume it. Many friends might brew a large bottle at once so they don't have to make coffee again for the coming week. However, FrontStreet Coffee recommends controlling the time within four days, that is, four days counting from when the brewing is completed. During this time the chance of spoilage is lower, and you are less likely to drink spoiled coffee that could affect your health. After four days, everyone can make their own decision~~

FrontStreet Coffee Recommendation

If you want to run FrontStreet Coffee's steeping experiment with fruit-forward beans, the cold brew lineup is a good place to start. FrontStreet Strawberry Sugar, a Geisha blend of Panama Geisha and Costa Rican honey-processed coffee, gives rose and orange on one side and grape, dried blueberry and strawberry fudge on the other, and can turn pleasantly wine-like if left to rest. FrontStreet Huakui, a naturally processed Ethiopian bean, concentrates magnolia, creamy strawberry, dried mango, guava and black tea through its long fruit contact, and it is one of the most floral cold brews FrontStreet Coffee offers. For a bright, juicy cup, FrontStreet Kenya Cherry Tomato shows cherry tomato, snow pear, black plum and smoked plum with low bitterness, while FrontStreet Yirgacheffe Gedingding delivers sweet berries, layered honey and a clean finish. If cost matters, blend FrontStreet Colombia Sidra with FrontStreet Costa Rica Tarrazu at 1:2 to keep the Sidra's passion fruit, grape and apricot sweetness while adding the Tarrazu's crisp citrus acidity.

For this style, FrontStreet Coffee grinds to fine-sugar size at about 80% pass rate on a China #20 sieve and steeps at a 1:10 coffee-to-water ratio in the refrigerator for 8-12 hours before filtering. After filtering, store the cold brew in a clean, sealed bottle under refrigeration for no more than four days, so the flavors stay fresh and clean.