Why does cold coffee taste better?
From the perspective of coffee brewing:
As we all know, every kind of coffee powder contains thousands of oils, chemicals and acids. These substances are collectively referred to as "soluble substances". It is these soluble substances that make coffee mellow and delicious. The process of coffee extraction can effectively release these substances.
Coffee brewing methods are mainly divided into two categories according to temperature and time:
1. Hot brewed (drip brewed) coffee: When it comes to hot brewed coffee, we naturally think of drip brewed coffee made with the old coffee machine or hand-washed drip brewed pot at home. This kind of coffee is very simple to make. We just need to pour hot water on the coffee powder. We can often drink classic drip coffee in restaurants. But in coffee shops, baristas use professional coffee machines to greatly improve the speed of making coffee. Their espresso is more fragrant, full of sour and bitter taste.
2. Cold brewed coffee: The easiest way to make cold brewed coffee is to soak coffee powder in cold water at room temperature, wait for several hours or even days, and then repeatedly filter the solution. Compared with the traditional hot brewed coffee, the produced coffee has a deeper taste, a very light sweetness and sourness, a richer taste and a higher concentration. Especially in hot summer, the cool taste makes people want to stop!
From a chemical point of view:
When coffee comes into contact with water, the soluble substances in it begin to react chemically, thus producing the familiar aroma and taste of coffee.
Soluble substances in coffee will begin to dissolve at 195-205℉, so theoretically, the taste and taste of hot brewed coffee should be richer than that of cold brewed coffee. At the same time, hot water will speed up the dissolution of soluble substances and make them volatile easily, so a lot of substances in coffee will evaporate with water molecules at high temperature and enter your nasal cavity, making you feel the aroma of coffee.
But accelerating the dissolution of substances will also bring some problems. Just boiled water will rot or oxidize some chemical elements in coffee, just like iron will rust when exposed to a lot of oxygen, making coffee sour and bitter. If you don't like these two flavors, then cold brewing coffee is definitely your best choice.
In the process of making cold brewed coffee, the oxidation and decay of chemicals will also occur, but the speed is extremely slow, so the bitterness and acidity of cold brewed coffee are softer than that of traditional hot brewed coffee. In addition, the slow oxidation and decay process also makes it easier to preserve cold brewed coffee, which can usually be stored in the refrigerator for 2-4 weeks. In contrast, the shelf life of hot brewed coffee is up to one day.
At this moment, you may ask, why is the water temperature so low and the taste of cold brewed coffee so strong? Indeed, the water temperature in the process of making cold brewed coffee is much lower than the ideal dissolution and volatilization temperature of aromatic oil and soluble substances, so you usually need longer time and double the coffee powder to increase the taste and concentration of coffee when making cold brewed coffee.
Although the taste of cold brewed coffee is better and richer, its aroma is not as good as that of traditional drip coffee, because the aromatic substances in coffee are difficult to volatilize at room temperature. In my opinion, this is the only drawback of cold brewed coffee.
The benefits of cold brewing coffee
1 can help improve metabolism and reduce fat absorption. Cold brewed coffee, like hot coffee, contains caffeine and chlorogenic acid, which helps to improve the metabolic rate of human body, decompose fat and reduce fat absorption in the body. Therefore, cold brewing coffee is considered to be helpful for slimming. The higher the metabolic rate of the body, the more calories it consumes. In a related experiment, the experimental group that consumed caffeine every day was the same as the experimental group that did not consume caffeine. ?
Long-term drinking helps to reduce the risk of type II diabetes, which is a chronic inflammatory disease. The patient's blood sugar level will be relatively high. If we don't pay attention to it, it may lead to complications such as kidney disease and retinopathy. Therefore, diabetics must see a doctor and follow the doctor's instructions. For people without diabetes, scientists believe that drinking 4 cups of coffee a day for a long time will help reduce the risk of diabetes in the future. This health benefit comes from coffee. ?
Many scientists believe that caffeine intake helps to boost the spirit and make the mood better, especially for those who can't sleep well because of anxiety. A study of 370 thousand people showed that the experimental group who drank coffee every day was less likely to feel depressed than the control group who didn't drink coffee. As for how much coffee to drink, this experiment thinks that drinking 1 cup of coffee every day can reduce the degree of depression by 8%. In another related experiment, people aged 63-74 were divided into experimental group and control group, and the experimental group was given caffeine according to their weight. Give 3mg caffeine per 1kg body weight, which is about equivalent to the amount of 2 cups of coffee for a person of medium height. Finally, it was found that the experimental group spent less time in a bad mood than the control group without caffeine. In addition, some scientists believe that caffeine in coffee can help improve brain function and improve our attention. For example, if something hits us, our reaction time will be faster and it will be easier to avoid it successfully. ?
4 can help maintain heart health. Cold brewed coffee is rich in nutrients to maintain heart health, including caffeine, chlorogenic acid, phenolic compounds, magnesium, trigonelline, lignans and so on. These ingredients can help lower blood pressure. Some scientists believe that drinking 3-5 cups of coffee (450-750 ml) a day can help reduce the probability of heart disease by 65,438+05%, but there are already patients with hypertension and instability.
What coffee beans are used for cold brewing coffee?
Basically, any kind of beans will do, but try to use freshly baked single beans. Although I have made Italian beans, they taste good.
How to make cold coffee?
The more exquisite cold brewing method is iced coffee. You need to buy an iced coffee pot and brew it according to the operation mode of the coffee pot. General iced coffee is now online100-around 200 yuan, and there are better ones. Basically, the ice-water mixture is slowly dropped into the coffee powder through flow control, which generally takes more than 10 hours to complete a pot of iced coffee.
There is also a relatively simple method, which is to grind the coffee powder directly with a press pot, pour it into the press pot, brew it with cold water, and then put it in the refrigerator. /kloc-you can take it out after 0/2 hours, which tastes worse, but the advantage is convenience.
Other variations are also possible. For example, I tried adding coffee powder directly into the pot, and then pouring it into the Eloda press for filtration, which is another flavor. Simply put, put the coffee powder in cold water in the refrigerator for a while, and then try to separate the coffee powder from the coffee liquid. You can do DIY according to your existing tools.