Understand what coffee quality control is what coffee quality control means

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Coffee quality test is divided into two modules: Italian style and single product.

Italian detection

Routine inspection: check the status, oil production and oil production of Italian beans on the same day, and judge whether the oil situation is reasonable according to the baking date, baking degree and the influence of temperature.

Make a cup of espresso test

Under the condition of fixed scale and grinding time of bean grinder (shop Mythos one) and constant temperature of coffee machine (shop Sanremo-opera) boiler, the flow rate of single / double part of espresso, extraction time, liquid color, liquid quantity, thickness of oil and flavor are consistent or not.

For example, the quantity of single concentrated powder produced by the store is 13g, the extraction time is 25s 25g-25.5g 35s, the weight ratio of extraction concentrated powder to powder is close to 1.2 65ml, the setting parameters of coffee machine are single 65ml and double 65ml, generally, the extraction to fast bleaching is the node to ensure the integrity of extraction and the balance of taste. If the deviation of the test results need to correct the above parameters one by one to ensure that each cup of espresso sweet and sour, alcohol thickness, oil balance to maintain a relative balance.

For example, the fat in espresso will be very thin, but the beans are not fresh enough for too long. If there are obvious rough bubbles in the oil of espresso, it is caused by too much carbon dioxide when the beans are too fresh.

For example, if the color of espresso oil is milky white, the extraction is excessive, while the dark brown is insufficient, and the normal oil color should be a beautiful yellowish brown with a texture similar to cream.

The color of Espresso oil can well reflect whether the extraction rate is reasonable, whether the amount of powder is enough, whether the filling pressure is appropriate, whether the water temperature of the coffee machine is correct and many other factors, there is a deviation should be adjusted accordingly.

Single product detection

Check the date and aroma of each bean, and the oil output of the deep-baked beans. Because the coffee beans are in the exhaust state, and the substances in the coffee beans interact with the air, the flavor of the beans changes slightly, so the state is different every day. After roasting, coffee beans will be adjusted according to different baking degrees and seasonal changes. Generally, the bean-raising period is shorter when the temperature is high, while the bean-raising period needs to be appropriately prolonged when the temperature is low.

For example, beans baked so deep in high temperature can be baked for about a week, and shallow baked for 3-5 days; low temperature deep baked beans take about 10 days, and shallow baked beans take about a week.

Select beans with later dates, insufficient aroma or abnormal oil production for brewing test, make sensory correction and elimination according to the situation of beans, and adjust the most suitable grinding degree, brewing water temperature and brewing mode of each bean, especially the new beans. From the change of taste, the correction of cooking, the time of bean cultivation, the influence of baking, etc., increase the mastery of beans and ensure the quality of each cup.

For example, under the same brewing technique, the overall flavor of a coffee today is fuller than that of yesterday, and the performance of sour and sweet is also better than that of yesterday, but it is a bit bitter and astringent, and the cleanliness is not OK, so it is necessary to thicken the grinding degree or measure whether the brewing water temperature is too high, make a balanced choice in the extraction, and it will be better to extract the flavor forward. If the flavor extraction is too thin, you need to adjust the fine grinding degree or increase the water temperature. Testing will encounter a variety of similar situations, appropriate adjustment of brewing parameters should be recorded and summarized at the same time.

Baristas should clearly understand the basic situation of each bean produced at home, such as origin information, flavor characteristics, roasting degree, suitable grinding degree, etc., and then fine-tune the techniques and parameters according to the characteristics of the beans. make a balance between sweet and sour, hierarchical, cleanliness, alcohol thickness and other elements to achieve the best possible expression state of beans, so as to convey the barista's understanding of a bean.