What kind of water do you use to make coffee? Will pure water make coffee sour? Can I make coffee with mineral water?

Maybe you are using good coffee beans, and the brewing parameters are all right. But there is always some negative flavor in a cup of coffee. Then it's probably the water.

You might say that water is colorless and tasteless, up to the drinking standard, isn't it all the same? Then you may have ignored the existence of minerals. Calcium, magnesium and bicarbonate ions are more or less found in impure water (distilled water). The scale produced during boiling is a good proof that the amount of these substances determines the softness and hardness of the water.

To start with some practical information, Christopher H. Hendon, a chemist at the Massachusetts Institute of Technology, put it in "Water for Coffee": "Water can change the nature of coffee."

Water itself also contains a lot of substances, magnesium, calcium ions and other high content, will make the water quality hard. The point is that the minerals in the water are adsorptive, and when the water encounters coffee powder, these substances will absorb the substances in the coffee. For example, the more eugenol absorbed by water, the stronger the woody flavor of the coffee.

Among them, the adsorption of magnesium ion is very strong, so water with high magnesium ion content usually makes coffee taste stronger (and caffeine content is high). At the same time, harder water also has a higher content of carbonate, which Hendon found can make coffee more bitter.

Therefore, magnesium ions are helpful to the extraction of coffee, but you can't control the content of substances in the water. As magnesium ions increase, other substances will also increase. Strong water is not suitable for brewing coffee, which will make a cup of coffee bitter.

So, pure water (0ppm) contains nothing, so it can be used to make coffee. In Hendon's words, [this is even worse]. Because the water of 0ppm does not contain any substance, its extraction effect will become worse, and the coffee made with pure water will often be very thin.

Therefore, the water suitable for brewing coffee should contain magnesium ions, calcium ions and other substances, but should not be excessive. SCA's "professional barista manual" states that the water quality TDS is 120-130ppm, while the water standard given by the American Fine Coffee Association in "Water for Coffee" shows that the TDS value of water between 75 and 250ppm is suitable for brewing coffee.

Therefore, in many large-scale cooking competitions, when the contestants introduce their own cooking parameters, most of them talk about the water being prepared by themselves. Just want to use the right amount of magnesium ion and calcium ion water to help extract coffee with strong flavor.

On the other hand, we seldom come into contact with the knowledge of water allocation, and we don't need to spend too much energy on making and blending water. So what kind of water is suitable for brewing coffee in reality? You can refer to the mineral water on the market, the label of mineral water will be marked with the content of various substances and TDS value. You can refer to the value of 75ppm to buy. Qianjie Coffee currently uses Nongfu Spring, the source of Qiandao Lake, with a TDS value of about 50ppm.

As to whether the filtered water in your home can be used to make coffee, so different household filtration systems have different filtering effects on water. You need to check the TDS of filtered water to see if it is between 75 and 250ppm.