Hand-brewed coffee beans how to select defective beans? What are defective beans? Which are defective beans?

Professional coffee knowledge exchange more coffee bean information please follow the coffee workshop (Wechat official account cafe_style)

We are picking out "defective beans".

The so-called defective beans (defected beans) are poor quality, bad coffee beans, or substances other than coffee beans mixed in the whole bag of coffee beans. We pick raw coffee beans before roasting (the more times we pick, the better the quality, the higher the price).

When picking out defects in raw beans, it is recommended to spread the beans on a dull black tray. For example, the color of fermented beans or unripe beans will be slightly yellow, and it is easier to identify them with dark trays. As for the manual sorting after baking beans, in order to easily see the difference in baking color, the cooked beans are also spread out on a tray covered with brown cotton cloth to make the sorting work easier.

After spreading out the coffee beans, you can start picking out defective beans, but a disorganized operation will only waste more time. The trick to making manual sorting more efficient is to first determine the priority of the work and think about which kind of defective beans to start with. First of all, the order of inspection is "color > gloss > shape". After getting rid of the foreign bodies and black beans that are obviously different from raw beans, there are dead beans, fermented beans, and unripe beans that do not have "luster", and finally defective beans such as shell beans and worm-eaten beans with strange shapes.

With regard to the proportion of defective beans sorted by hand, about 1530% of the raw beans treated by washing and 40% of the sun-dried beans. Of course, it is ideal to buy raw beans with few defects in the first place, but defects are inevitable, so it is necessary to estimate in advance the number of beans that will be reduced after deducting defective beans before the necessary purchases can be calculated. Because of a defective bean, it is a great pity that the coffee that takes time and effort to brew will be destroyed once. In order to avoid regret, it will be safer to pick it out decisively if it is difficult to judge whether it is normal or defective.

Common impurities in coffee beans:

1. Stone

Coffee beans dried naturally in the sun are likely to be mixed with pebbles, gravel, wood chips and other foreign bodies. Occasionally a piece of glass or coins will be found.

2. Cereals

As in the case of stones, coffee beans dried naturally in the sun may be mixed with cereals or seeds such as corn, and pepper grains have been seen.

Common defective bean patterns:

1. Shell beans, broken beans

Beans that become shell-shaped because of developmental problems are called "shell beans"; beans that are damaged during treatment or transportation are called "broken beans", both of which can cause uneven baking.

2. Fermented beans

When treated by water washing method, polluting fermented beans are produced in the fermentation tank. Delayed processing or improper preservation can also occur after harvest, and beans will smell funny when baked.

3. Moth-eaten beans

This is because pests such as coffee bark beetles lay eggs on coffee trees, and the hatched larvae eat coffee fruits to form cavities, which is the reason for the foul or strange taste of coffee.

4. Moldy beans

Beans that are moldy due to incomplete drying, transportation or improper preservation will remain moldy even after baking.

5. Unripe beans

Beans harvested before the coffee fruit is ripe. Coffee mixed with unripe beans will have a strong fishy smell, giving off a disgusting, smelly smell.

6. Black beans

Beans that fall black before harvest, or beans that are completely fermented and damaged. It is the source of the foul smell and rotten smell of coffee.

7. Dead beans

Beans that fail to bear fruit normally will lead to weak flavor and strange taste of coffee. The color after baking is also not good, so it is easier to distinguish after baking.

8. Smelly beans

Dry when the flesh is attached, or remove incomplete beans from the pulp. Stinky beans give off the smell of iodine or soil.

9. Sheepskin membrane beans

Due to incomplete shelling and other reasons, the beans with residual endocarp are the reasons for the astringent or miscellaneous taste of coffee.