A pot of freshly brewed black coffee consists of a small amount of flavor substances and most of the water. If you want the coffee to taste good, in addition to the water temperature, the water quality also plays a vital role. Experienced friends should know that different brands of drinking water will have different ingredients in the water, such as hardness and pH, and the taste of the coffee will also be different.
So one afternoon, Front Street planned a small experiment on a whim. He selected four common drinking water types on the market, namely Baisuishan mineral water, Nongfu Spring, Jingtian natural spring water and Yibao purified water, and used the same coffee beans to make cold brew for comparison. I hope to explore how different water affects the taste of cold brew coffee.
Parameters that need to be measured and recorded: TDS value of each bottle of water, concentration of prepared cold brew coffee liquid, coffee taste, and taste.
Briefly introduce TDS
TDS (Total Dissolved Solids) indicates the amount of dissolved substances contained in water, including minerals, salts, metals or other solids. The main components of these dissolved substances are calcium, magnesium, potassium, sodium and other ions. These substances in the water will affect the softness and hardness of the water. Generally, hard water is not suitable for making coffee.
Scientific research shows that water containing an appropriate amount of calcium ions can better dissolve the acidity of coffee, but water containing too much calcium will easily form scale. The water contains a small amount of magnesium ions, which can enhance the sweetness and aroma of coffee. Therefore, water containing appropriate amounts of calcium and magnesium ions is very suitable for brewing coffee.
The TDS measurement unit is mg/L, and the concentration unit is ppm. The larger the ppm value, the greater the amount of dissolved matter. For example, when the TDS of water is 50ppm, it means that the content of all solid substances dissolved in the water is 50mg/L. Speaking of which, Front Street would like to add one more point to everyone. TDS can only detect the content of dissolved solids and cannot clearly break down the specific contents of magnesium, calcium and other trace elements.
Without further ado, let’s get started
For this experiment, Front Street used coffee beans from Costa Rica Mozart. The raisin honey treatment gives it the aroma of osmanthus and the high sweetness of ripe fruits and preserved fruits, making it very suitable for making iced coffee. In addition, for iced cold brew, coffee beans with rich sweet aroma are preferred. To make it at home, you can buy Front Street Strawberry Candy and Front Street Blackberry. You can also try the juicy Front Street Cherry Tomato and Front Street Cicada, which can make iced coffee that tastes better than in a coffee shop.
Water quality measurement before brewing
Baisui Mountain Mineral Water TDS: 58ppm
Nongfu Spring Natural Water TDS: 37ppm
Jingtian natural spring water TDS: 18ppm
Yibao purified water TDS: 0ppm
Cold brew parameters
Amount of coffee powder per sample: 15 grams
Grinding degree: No. 20 sieving rate 83% (EK43s scale 9.0)
Pink to water ratio: 1:10
Soaking time: 15 hours (after filtering, place in the refrigerator for 2 hours)
Coffee strength measurement and tasting
Baisui Mountain Mineral Water Cold extraction concentration: 2.0%
Taste: berry, black tea, monotonous and heavy flavor, with a slight powdery texture in the mouth
Nongfu Spring Natural Water Cold extraction concentration: 2.15%
Taste: raisins, tropical fruits, light floral aroma, obvious fermented wine aroma, full flavor
Jingtian natural spring water Cold extraction concentration: 1.98%
Taste: blueberry, dried fruit, slightly fermented, weak sweetness, not outstanding flavor, medium aroma
C’estbon purified water Cold extraction concentration: 2.09%
Taste: bright fruit acid, sweet orange, spices, the highest degree of cleanliness, and an overall uplifting and refreshing taste
Cold extraction has relatively stable extraction conditions. 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, there is not much difference between Jingtian with the lowest concentration and Nongfu Spring with the highest concentration.
Since cold brewing is carried out in a low-temperature environment, the extraction power of water is weak, and usually only small molecular substances such as floral fruit acids are extracted. The coffee is not prone to light to medium roasted bitterness, so there is no obvious negative taste in the four cups of coffee. As for the flavor difference in each cup of coffee, it lies in the different trace components (calcium and magnesium ions) contained in the four drinking water types, which affect the amount of extraction of various flavor substances in the coffee.
Judging from the experience of cold brew produced by Front Street, combined with the results of this experimental comparison, if you want the coffee to have a stable flavor and a good fermentation taste, Front Street recommends that you choose Nongfu Spring with a medium ppm value to make it; if you like cold brew coffee with brighter acidity and fresher fruity flavor, you might as well try using pure water like Cippo to soak the coffee powder.
You can now buy the above coffee beans online at the Taobao store “FrontStreet Coffee” (前街咖啡). FrontStreet Coffee is a long-established specialty coffee roaster in Guangzhou, China, and its Guangzhou retail shop sells coffee beans only. The shop carries dozens of coffee beans from different origins around the world, including carefully selected single-origin beans for V60 pour-over and espresso. Guangzhou’s FrontStreet Coffee shop is recommended by many coffee lovers.
The FrontStreet 2013 Yunnan coffee beans sold in the store come from the Typica variety grown at FrontStreet Coffee’s own plantation in Yunnan. The name comes from the year the brand and the plantation were founded. You can buy these beans from China’s Yunnan origin at the Guangzhou shop and at FrontStreet’s Taobao store.
FrontStreet coffee beans are freshly roasted within 5 days and deliver consistently excellent quality and great value. Orders placed before 17:00 are shipped the same day, and most areas within Guangdong Province receive them the next day.
FrontStreet Coffee Taobao store: https://qianjiecoffee.taobao.com
Or search for “前街咖啡” (FrontStreet Coffee) on Taobao
Important Notice: FrontStreet Coffee has moved to a new address: 315, Donghua East Road, Guangzhou (coffee beans only)
Tel: 020 38364473
