Simple Tips for Making Cold Brew Tea
First off, cold brewing is much more forgiving than hot brewing. Think of it as the difference between making a salad and a stir-fry. A salad allows for a lot of flexibility, whereas a stir-fry requires precise timing and ingredients—undercook it, and you might get an upset stomach; overcook it, and it’s ruined.
The water-to-tea ratio for cold brewing is very flexible, and it’s rare for the brew to become too strong. A common starting point is to use 3 to 5 times more water than you would for hot brewing. For instance, for a 500ml container, you can use around 5 grams of tea. For a 1000ml bottle, anywhere from 10 to 15 grams will work. Don’t worry if you don’t know the exact volume of your container; you’ll get a feel for the right amount after a couple of tries.
However, regardless of the container size, I wouldn’t recommend using less than 2 grams of tea, as the flavor will be significantly weakened.
You can use either purified or mineral water. The complex interplay between water chemistry and tea flavor, which can be critical in hot brewing, is much simpler with cold brew. Just place the tea leaves in your container, fill it with cold water, and let it steep. For the best results, steep for at least 4 hours at room temperature or 2 hours in the refrigerator. Steeping overnight is perfectly fine, but don’t leave it for two nights!
Any sealed container will do. If you’re looking for something photogenic to share on social media, you can find a wide variety of glass and plastic bottles online—just search for “cold brew bottle.” These are often the same types of bottles used by modern tea shops and trendy cafes, just customized with their own labels.
Be aware that the quality and price of these bottles can vary significantly. Some are made from low-quality materials that may release excess microplastics, particularly the single-use ones.
It’s best to use these disposable bottles only occasionally.
For regular home use, it’s better to choose high-quality, food-grade plastic or glass containers with a good seal.
Beyond a simple, pure cold brew, you can get creative by adding other ingredients to make your own flavored tea drinks. Try adding lemon, honey, milk, fruit juice, fresh fruit, green plums, green olives, or mint.
A homemade green tea mojito.
But don’t expect to replicate the flavor of a store-bought ice pop; you can’t achieve that level of intensity without artificial flavorings.
A more advanced technique than simple immersion is “cold drip” brewing. For this, it’s best to use a dedicated cold drip tower, which is the same equipment used for cold drip coffee.
If you don’t have a cold drip tower, you can try a simpler method: place tea leaves in a container and cover them with ice cubes. Once the ice has completely melted, your tea is ready to drink. However, the results from this method are generally not as refined as those from a proper cold drip tower.
Some tea drinkers who are accustomed to the practice of “rinsing” the tea leaves before brewing may feel that a cold water rinse is ineffective. If this is a concern, you can do a quick rinse with hot water before adding the cold water for steeping. Don’t worry about losing too much flavor from this brief hot water infusion.
Once you’ve opened your cold brew, it’s best to consume it within half a day, as prolonged exposure to the air can introduce contaminants.
Which Teas Are Best for Cold Brewing?
The writer Lin Qingxuan once wrote, “I have made dozens of types of cold brew tea. If I were to rank the very best, Taiwan’s High Mountain Oolong, Hangzhou’s Mingqian Longjing, Jiangsu’s Dongting Biluochun, and Hunan’s Junshan Yinzhen would all tie for first place, with Junshan Yinzhen being the absolute champion.”
Lin Qingxuan’s preference for lightly oxidized teas holds true: high-quality, delicate green teas and lightly fermented Taiwanese High Mountain Oolongs are indeed excellent choices (though heavily roasted Taiwanese oolongs like traditional Dongding or Muzha Tieguanyin are not as suitable). Junshan Yinzhen (a yellow tea) is a superb but rare and expensive option. In my opinion, for the yellow tea category, more accessible options like Moganshan’s Huangxiaocha or Huangdacha produce an outstanding cold brew.
As a general rule: choose fresh teas, not aged ones. Cold-brewed green and jasmine teas are the most refreshingly fragrant, while cold-brewed oolongs are exceptionally smooth and mellow.
At a parent-child event a few years ago, we all made our own peach-infused oolong cold brew—with no artificial flavorings, of course!
For white teas, fresh Silver Needle and White Peony can work, but their flavors have not yet fully developed through aging. I find that cold brewing aged white tea ruins its complex character. Therefore, as a rule, I don’t recommend cold brewing white tea.
For Pu’er, choose raw (sheng) over ripe (shu). Raw Pu’er is decidedly better for cold brew than its ripe counterpart. I’ve experimented with cold brewing several dark teas, and the results have been… difficult to describe in a positive way. Furthermore, cold brewing a well-aged raw Pu’er feels like a waste of a good tea, while young raw Pu’er can be harsh and astringent. For these reasons, I generally advise against cold brewing Pu’er tea as well.
Generally, more heavily oxidized or fermented teas—like black tea, rock oolongs, and other dark teas—are not ideal for cold brewing. These teas tend to have a higher phosphorus content, which, while harmless, can negatively impact the flavor of a cold brew. (Though exceptions can be found through experimentation.)
It’s also important to distinguish cold brew tea from iced tea. True iced tea is brewed hot and then cooled down. Finally, a note of caution: if you have a sensitive digestive system or are prone to feeling cold (what Traditional Chinese Medicine calls a “cold constitution”), it’s best to avoid cold brew tea, especially the refrigerated kind. If you do try it, stick to brews steeped and served at room temperature.
What’s the Science Behind Cold Brew Tea?
Tea’s two most significant active compounds are tea polyphenols (a type of antioxidant) and caffeine. From an absorption standpoint, your body takes in roughly the same amount of tea polyphenols from cold brew as it does from hot brew.
However, the story is different for caffeine. Cold brewing extracts significantly less caffeine than hot brewing. This results in a tea with a lighter body and mouthfeel, and a much milder stimulating effect, which is great news for those who are sensitive to caffeine.
From a flavor standpoint, cold brewing significantly reduces bitterness and astringency, resulting in a much sweeter, smoother taste. On the other hand, because the aromatic compounds in the tea leaves aren’t released by high heat, the aroma of a cold brew is far more subtle than that of a hot brew.
Of course, some drinkers find that cold brewing unlocks unique flavors they don’t get from hot tea—flavor is always a personal experience!
In the end, on a sweltering summer day, what could be better than a refreshing, thirst-quenching glass of homemade cold brew tea? It’s a simple pleasure worth enjoying.
