Coffee Apprentice: the notes we took in those years!

Guide to Caxiang: as the saying goes, a good memory is not as good as a bad pen, many memories will become blurred with the passage of time, but what is written down in black and white, no matter how long it takes, it is still there! The notes you wrote down when you were an apprentice may have a lot of inspiration for you now! Next, a group of "high-energy magic maps" will take you into the coffee world of shou (can)! (I read a lot of books, so don't lie to me.)

one。 Factors affecting extraction uniformity:

Very well, this high-energy picture is still within the understanding of the small coffee. After all, it is not "illustrated with text". After combing it by itself, the partner may want to express the following views:

The factors affecting the extraction uniformity are as follows: 1. Extraction time, 2. Extraction temperature, 3. Manual operation, 4. Hardware adjustment.

Then control these factors: 1. Fixed extraction time, 2. Find out the best grinding scale, 3. Find out the appropriate cooking water temperature, 4. Reduce human error, 5. 5%. Check whether the coffee beans are fresh, 6. Verify that the equipment needs to be upgraded.

Finally, we can see the results. A, B and C represent: A. The volatile ingredient (aroma) B. Soluble and insoluble components in coffee C. The burnt, bitter, raw and astringent taste of coffee. When we fix other factors and divide the extraction time into three short, medium and long periods, we can get the following results:

Time (short): a dispersed less, retained intact, B dissolution rate was low, taste light and thin, C did not have time to dissolve out.

Time (middle): a dispersed a little more, the aroma retained about half, B dissolved medium, the taste was rich, relatively thick, C dissolution rate was low.

Time (long): a dispersed most, leaving only 10% or less, B dissolution rate is high, consistency is high, C dissolution rate is high, uncomfortable taste covers good taste.

Xiao Cafe thinks that this note should be unfinished!

two。 Grinding degree

This is a model full of pictures and texts, and the small coffee is here to give praise! The degree of grinding is not enough. There are metaphors and physical objects for reference. Mom doesn't have to worry anymore. I don't know what moderate grinding is anymore!

The degree of grinding should be proportional to the extraction time. The roughness of coffee grinding will directly affect the extraction time and extraction rate. The finer the coffee is ground, the denser the powder layer is, the more coffee powder particles are in contact with hot water, the greater the extraction resistance, the easier it is to prolong the extraction time and improve the extraction rate, and it is easy to over-extract. On the contrary, the coarser the coffee is, the larger the gap in the powder layer is, the less coffee powder particles are in contact with hot water, and the weaker the extraction resistance is, the more difficult it is to prolong the extraction time, and reduce the extraction rate, which is easy to be insufficient. Therefore, the finer the coffee is ground, the longer the extraction time and the higher the extraction rate; the thicker the coffee is, the shorter the extraction time is and lower the extraction rate. Under normal conditions, the fineness of coffee is inversely proportional to the extraction time and extraction rate. The coarser the powder is, the smaller the extraction resistance is, the greater the coffee flow is, the shorter the extraction time is, the lower the extraction rate is, and the lighter the taste is.

Deep roasted beans are thicker and shallow roasted beans are slightly lighter. In addition, before determining the grinding degree of coffee beans, the veteran will first look at the color and oil production of cooked beans. The lighter the roasted coffee is, the more complete and hard the fiber is, the more difficult it is to extract. It is appropriate to pick and grind slightly, but not too fine, so as not to highlight the sharp sour taste. The deeper the roasting degree of coffee, the deeper the damage to the fiber, the easier to extract, it is appropriate to pick a little rough grinding, deep roasting grinding too fine will be bitter. Therefore, the degree of grinding of deep-roasted coffee is generally thicker than that of shallow roasted beans.

Roughness can control bitterness is a good way to control bitterness, because the finer the grinding, the higher the extraction rate, the easier it is to extract high molecular weight astringent bitter substances such as chlorogenic acid, quinic acid, caffeine and carbides. On the contrary, if the grinding is too rough, the lower the extraction rate is, the more difficult it is to extract the astringent bitter substance with high molecular weight, but the sweet taste with medium molecular weight may also remain in the coffee grounds because of insufficient extraction, which is a waste. The scale is not immutable. Do not use the same grinding scale for playing coffee. If you know that the density and baking degree of each bean are different, the required scale will not be the same. The scale of very hard beans or shallow roasting can be slightly adjusted to be finer, and the deep roasting can be adjusted thicker. If you think a bean tastes bitter and salty on scale # 3, this is excessive extraction, which can be adjusted to # 3.5 or # 4, which will significantly improve the bad taste spectrum, and vice versa. In addition, the bean grinder should be diligent in maintenance, regularly remove the knife head and remove the oil dirt inside. The knife head is consumable, and it will be dull every 800 to 1000 pounds. Remember to replace it, otherwise the grinding particles will be half-thick and half-thick, which will cause uneven extraction and damage the good flavor of coffee.