Both are made by adding water to coffee grounds, so why do hot brew and cold brew taste so different? Hot coffee emphasizes aroma and temperature, while cold coffee is a greater test of technique and quality. This article starts from the definition, brewing methods, and chemical principles of cold brew coffee, compares the differences between hot brewing and cold brewing in flavor, bitterness and acidity, and storage time, and explains why low-temperature slow extraction can bring a softer mouthfeel. At the end, it also combines a variety of single-origin beans and espresso blends from Front Street Coffee to offer ideas on what coffee beans are suitable for cold brew coffee, helping coffee lovers find their own cup of iced coffee in summer.

For more specialty coffee knowledge, please follow the WeChat official account: Front Street Coffee (FrontStreet Coffee) Tea carries Chinese culture, while coffee has also gradually entered the public eye, ranking among the top three beverages and becoming an indispensable part of daily life. Many people like coffee, but may not clearly understand why it can present such diverse tastes and flavors. Front Street tells everyone: coffee brewing is actually as particular as tea, and even requires attention to more details than tea. The raw materials for coffee brewing are nothing more than coffee grounds and water, but once the brewing method changes, the final taste will be completely different. Some people prefer hot coffee; a warm cup is especially comforting in winter. In summer, a cup of iced coffee is refreshing and satisfying. Front Street believes: hot coffee is about aroma and temperature; warm coffee is about layers and flavor; cold coffee is about technique and quality. Different temperatures bring different taste experiences, so what exactly is the difference in coffee flavor related to?

Front Street believes: whether hot coffee or cold coffee, the raw materials used are the same. Although roasting and grinding methods have a great impact on the final aroma, mouthfeel, and flavor of coffee, in the final analysis, the greatest influence on coffee taste is still the brewing method. Different brewing tools and brewing techniques will make coffee present completely different tastes, sweetness, and body. We all know that hot water brewing coffee is pouring hot water into coffee grounds and dripping out coffee liquid; then what about cold coffee? Is it brewed with cold water? Is all coffee suitable for brewing with cold water? The answer is: of course not.

Front Street believes: coffee is best not brewed with cold water. If the water temperature is not high enough, the coffee is prone to clumping, and the taste will also be too bitter. Some coffees can be brewed with cold water, such as Nescafe iced coffee, but most coffees are best not brewed with cold water, otherwise the coffee will not dissolve easily and will be hard to swallow. It has no effect on the body, but the taste will be compromised. Instant coffee can be soaked in cold water, but the taste may not be ideal. Generally speaking, the most suitable water temperature for brewing coffee is between 88 and 94 degrees Celsius. Avoid brewing directly with just-boiled rolling water. After the water boils, let it sit for 1 to 2 minutes before using it to brew coffee. What is cold brew/cold extraction coffee? Since cold brew coffee has also become one of the cold drinks that everyone in China likes, how exactly is so-called cold brew coffee/cold extraction coffee made?

Cold brew coffee is a pure black coffee liquid made by directly soaking coffee grounds in room-temperature or ice water at room temperature or low temperature. Due to low-temperature extraction, the flavor release of coffee grounds is much slower than at high temperature, so the soaking time will vary with room temperature/refrigerator temperature, and the total extraction time often requires 8-24 hours. Because it can produce iced coffee with obvious aroma and high body without any technique or cumbersome brewing equipment, and can be soaked at night and drunk in the morning, it has become a favorite of many office workers.

Since coffee brewing is divided into hot coffee and cold coffee, that is, according to time and temperature, coffee brewing methods include hot brewing and cold brewing; then Front Street will take everyone to understand the flavor differences brought by these two different brewing methods: 1. Hot brewed (drip) coffee: For hot coffee, what we think of is hand-drip coffee. This kind of coffee is very simple to make; you only need to pour hot water onto the coffee grounds. For example: at Front Street Coffee (FrontStreet Coffee) stores, you can often drink classic drip coffee; for example, the classic espresso blend coffee made by Front Street Coffee (FrontStreet Coffee) baristas. The espresso produced has rich golden crema and a nutty aroma. When tasting, there will be a toasty coffee bitterness, but accompanied by more of a creamy, full mouthfeel, and after swallowing, the bitterness also dissipates, leaving a lingering fragrance on the lips and teeth.

2. Cold brewed coffee: Cold brewing takes a longer time. The simplest way to make cold brew coffee is to soak coffee grounds in cold water at room temperature, wait several hours or even days, and then repeatedly filter the solution. The coffee produced has a deeper taste, extremely light bitterness and acidity, richer flavor, and its concentration is also higher than traditional hot brewed coffee. Especially when drunk in hot summer, the icy refreshing taste is irresistible! From a chemical perspective: When coffee comes into contact with water, the soluble substances in it begin to undergo chemical reactions, and the result creates the aroma and taste of coffee that we are familiar with.

The soluble substances in coffee begin to dissolve at a water temperature of 195-205°F, so theoretically the mouthfeel and taste of hot brewed coffee should be richer than cold brewed coffee. Hot water also accelerates the dissolution rate of soluble substances, making them highly volatile, so a large number of substances in coffee will evaporate together with water molecules under high-temperature conditions, enter your nasal cavity, and let you experience the aroma of coffee. But accelerating the dissolution of substances also brings some problems. Just-boiled water will cause some chemical elements in coffee to deteriorate or oxidize. This is like iron rusting when exposed to a large amount of oxygen, giving coffee an acidic and bitter taste. If you do not like these two tastes, then cold brew coffee is definitely your best choice.

During the production of cold brew coffee, oxidation and deterioration of chemical substances also occur, but the rate is extremely slow, so the bitterness and acidity of cold brew coffee are softer than traditional hot brewed coffee. In addition, the slower oxidation and deterioration process also makes cold brew coffee easier to preserve; stored in the refrigerator, it can usually be kept for 2-4 weeks. In comparison, the shelf life of hot brewed coffee is at most one day. Is cold brew coffee better tasting than hot brew coffee? Front Street believes: when the water temperature is relatively high, aromatic molecules perform very actively at this time, the aroma is strongest, and the nose can easily enjoy the aroma of coffee. At this time, you can feel this cup of coffee by smelling its aroma. But if you drink coffee at this temperature, because the lips and tongue will feel a burning pain, our perception of flavor is basically unable to distinguish too many tastes at this time, especially bitterness.

I believe many friends have had this experience: some coffee can barely be drunk while hot, but once it cools down, it is so bitter that it cannot be swallowed. It is like drinking Chinese medicine, blow on it and take a sip; if you do not drink it while hot, once it cools, it is simply impossible to swallow. In fact, it is not that the taste of the coffee or Chinese medicine has changed, but that the lower the temperature, the stronger the taste buds' perception of bitterness. Soaking coffee in cold water still has some advantages: the mouthfeel is softer, and the most important thing is convenience. When you want to drink coffee, you no longer need to boil water. Why can cold brew coffee still taste so rich when the water temperature is so low? Indeed, during the production of cold brew coffee, the water temperature is far below the ideal dissolution and volatilization temperature for aromatic oils and soluble substances, so usually when making cold brew coffee, you need a longer time and double the coffee grounds to increase the taste and concentration of the coffee.

Although cold brew coffee has a richer taste, its aroma cannot match traditional drip coffee. This is because the aromatic substances in coffee are difficult to volatilize at room temperature. Because the amount of coffee grounds used and the production time are longer, the selling price of cold brew coffee is usually a bit more expensive than hot brewed coffee. Front Street believes: what hot coffee drinks is the experience of flavor and mouthfeel brought by temperature changes. The flavor changes differently at each temperature, which is to say that the flavor hot coffee brings to everyone has more layers. Of course, whether hot coffee or cold coffee, both have their own characteristics and are very popular, because everyone's taste is different! Front Street Coffee (FrontStreet Coffee) has more than 50 kinds of single-origin beans, as well as many espresso coffee beans recommended by baristas - Front Street Black Cocoa Blend, Specialty Blend, Commercial Blend, and Warm Sun Blend. No matter what taste you like, you can come to Front Street to discuss and taste together! For professional coffee knowledge exchange and more coffee bean information, please follow Coffee Workshop (WeChat official account cafe_style) For more specialty coffee beans, please add the private WeChat of Front Street Coffee (FrontStreet Coffee), WeChat ID: qjcoffeex

The above content is compiled by CoffeeHunters, a coffee news website.