What is the effect of different water quality on the flavor of cold-extracted coffee? What kind of water is best for brewing coffee?

A pot of freshly brewed black coffee consists of a small amount of flavor and most of the water. In addition to the water temperature, the water quality also plays a crucial role in making the coffee taste good. Experienced friends should know that different brands of drinking water, the ingredients contained in the water will be different, the hardness and pH will be different, presumably the coffee taste will also form a certain difference.

So one afternoon, Qianjie suddenly planned a small experiment, purchased four common direct drinking water on the market, namely Baisui Mountain mineral water, Nongfu Spring, Jingtian natural spring water and Yibao purified water, with the same coffee bean cold extraction for comparison. We hope to find out how different water affects the taste of cold-extracted coffee.

Parameters to be measured and recorded: TDS value of each bottle of water, concentration of cold coffee solution prepared, coffee taste and taste.

A brief introduction to TDS

TDS (total dissolved solids) indicates the amount of dissolved matter contained in water, including minerals, salts, metals or other solids. The main components of these dissolved matter are calcium, magnesium, potassium, sodium and other ions. These substances in water will affect the hardness of water, generally hard water is not suitable for coffee.

Scientific research has shown that water containing the right amount of calcium ions can better dissolve the acid of coffee, but water containing more calcium will easily form scale. The water contains a small amount of magnesium ions can enhance the sweetness and aroma of coffee. Therefore, water containing appropriate amounts of calcium and magnesium ions is very suitable for brewing coffee.

TDS is measured in mg/L and concentration is measured in ppm. The higher the ppm value, the higher the amount of dissolved matter. For example, when the TDS of water is 50ppm, it means that the content of all solids dissolved in water is 50mg/L. Speaking of this, Qianjie should add one more point to everyone. TDS can only detect the content of dissolved solids, and cannot clearly subdivide the specific content of magnesium, calcium and other trace elements.

Without delay, start the actual operation

In this experiment, the coffee beans selected in the front street are Costa Rica Mozart. The raisin honey treatment method makes it fragrant with osmanthus and sweet as ripe fruit and preserved fruit, which is very suitable for making iced coffee.

Water quality measurement before brewing Baisuishan mineral water TDS: 58ppm Nongfu Spring natural water TDS: 37ppm Jingtian natural spring water TDS: 18ppm

Ipoh purified water TDS: 0ppm

cold extraction parameter

Amount of coffee powder per sample: 15 g

Grinding degree: No. 20 sieving rate 83%(EK43s scale 9.0)

Powder water ratio: 1:10

Soaking time: 15 hours (after filtration, place in refrigerator for 2 hours)

Coffee concentration measurement and tasting Baishuishan mineral water cold extraction concentration: 2.0%

Palate: Berries, black tea, monotonous flavor, slightly pink texture on the palate

Nongfu Spring Natural Water Cold Extraction Concentration: 2.15% Taste: raisins, tropical fruits, light floral fragrance, fermented aroma obvious, full flavor Jingtian Natural Spring Cold Extraction Concentration: 1.98% Taste: blueberries, dried fruits, slightly fermented, sweet feeling weak, flavor not prominent, aroma is quite right Yibao Pure Water Cold Extraction Concentration: 2.09% Taste: bright fruit acids, sweet oranges, spices, highest cleanliness, overall refreshing

Cold extraction has relatively stable extraction conditions, and the concentration is directly determined by the ratio of powder to water, grinding degree and soaking time. Therefore, under the premise of only changing the water quality, even Jingtian with the lowest concentration and Nongfu Spring with the highest concentration are not too different.

Because cold extraction is carried out in a low temperature environment, the extraction strength of water is weak, usually only small molecular substances such as floral acid are extracted, coffee is not easy to appear light to medium roasted bitterness, so four cups of coffee have no obvious negative taste. As for the flavor difference of each cup of coffee, it lies in the different trace components (calcium and magnesium ions) contained in the four drinking water, which affect the extraction amount of various flavor substances in coffee.

According to the experience of cold extraction produced by previous streets, combined with the results of this experiment comparison, if you want to make coffee that can stably exert flavor and has good fermented taste, Qianjie recommends that you choose Nongfu Spring with medium ppm value to make it; If you like cold extraction coffee with brighter acid and fresher fruit flavor, try to soak coffee powder with pure water such as Yibao.

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Front Street Cafe

No.10 Baoanqian Street, Yandun Road, Dongshankou, Yuexiu District, Guangzhou City, Guangdong Province