Necessary to open a coffee shop, knowledge of coffee brewing

Follow the caf é (Wechat official account vdailycom) and found that Beautiful Cafe opened a small shop of its own.

-Segmentation line-

Preparation before brewing:

1. Coffee powder expands after boiling water is injected, so choose a slightly larger strainer.

two。 Make the outside of the filter, fully twist the water off the wrinkles and straighten it out.

With regard to the safekeeping of flanged velvet filter:

When using a new flannel filter, in order to remove the water paste or smell that will remain on the cloth, wash it with a brush (do not use soap or soap powder at this time. After that, boil the used coffee powder with water for five minutes before washing it with water.

Preservation method of flannel filter:

The filter cloth should be well washed with water after use, and water should be added to the freezer to prevent oxidation. And the water must be changed every day, otherwise the scale will cause clogging of the cloth. When in use, brew it with warm water, then fully wring it out and then use it.

Program:

① cloth as the inside, coffee powder 10-12g per person into the filter cloth, and then flatten the coffee powder.

② shallow roasted coffee boiled water temperature is about 95 degrees, while deep roasting is lower, the initial thin line injection, while controlling the amount of boiling water while making a round injection. The coffee powder should be steamed for 20 seconds after brewing, which must be "suspended" during this period. After the second time, the same amount of boiled water is injected in a vortex each time, from the center to the outside and back to the center.

③ do not let the boiled water drop completely, just inject it according to the number of people, and take it out when the boiling water in the filter cloth is still in the remaining state.

At the end of ④ extraction, the coffee liquid should be heated instead of boiling when the temperature decreases. Shake gently and pour into the cup.

The researchers made coffee with American coffee machine, Naples pot, mocha pot and Italian coffee mechanism, and analyzed the pH value, total solids, total phenols, antioxidant activity, caffeine and volatile substances of different coffee. Let's focus on the last three.

1. Antioxidant activity

Do not think that coffee is just a refreshing drink, let alone a drink filled with X, coffee is actually rich in antioxidants, with a good antioxidant effect. Don't say much about what antioxidation is, think about your favorite vitamins C, E, anthocyanins. In terms of antioxidant activity per unit volume of coffee, the coffee made by Italian coffee machine is the highest and that made by American coffee machine is the lowest. But taking into account the difference in the size of each cup, a cup of coffee made by a mocha pot or an American coffee maker has better antioxidants.

two。 Caffeine

Caffeine is a central nervous system stimulant, and the refreshing effect of coffee mainly comes from caffeine. Or the content of a cup of coffee, the coffee made by American coffee machine contains the most caffeine. The caffeine content of coffee made from Neapolitan pot, mocha pot and espresso machine is about 1/3 of that of American coffee. So for a pick-me-up, have a cup of coffee made from an American coffee machine.

3. Volatile substances

These substances constitute the aroma of coffee, and the difference in the content of each substance constitutes the difference in the aroma of coffee.

Furan compounds have aromas of nuts, caramel, tobacco, flowers and ether. Coffee made by Italian coffee machine has higher concentration of furan compounds, coffee made by American coffee machine, Naples pot and mocha pot, and the content of furan compounds decreases in turn.

Phenolic compounds have a smoke-like smell. The coffee made by mocha pot contains higher content of these compounds, the coffee made by American coffee machine and Naples pot has lower content of phenols, and the coffee made by Italian coffee machine has the lowest content of phenols.

Pyrazine compounds give coffee the smell of hazelnut and coffee. The coffee made by mocha pot has relatively high content of pyrazine compounds, while the coffee made by Naples pot, American coffee machine and Italian coffee machine has lower pyrazine content in turn.

Aldehydes produce fruity, astringent, chocolate and malt aromas. Coffee made from espresso and American coffee machines contains higher levels of aldehydes, while coffee made from Neapolitan pots and mocha pots contains lower aldehydes.

The sulfide has the taste of cheese, garlic and sulfur. The coffee made by Italian coffee machine has higher sulfide content, followed by the coffee made by mocha pot, and the coffee made by American coffee machine and Naples pot has lower sulfide content.

According to the analysis of various compounds, the coffee made by mocha pot has tobacco, scorched and spicy flavor, while the coffee made by Italian coffee machine has sulfur, fruity, astringent, floral and chocolate flavor. Naples pot coffee has hazelnut, nutty and scorched flavor, while the coffee made by American coffee machine has berry, ether, butter, fruit, green and chocolate flavor.