I heard that you still can’t identify defective beans?

Many bakers

Maybe you all have similar experiences:

Put the beans in the sack directly into the coffee roaster

Even if the smell is very fragrant

But even if we remedy it later (using various advanced high-tech equipment)

It tastes weird when you drink it.

The reason

Because a key step was overlooked before baking

Sorting beans

Defective coffee beans for a cup of coffee

The impact cannot be underestimated

Japanese experts have studied

10 grams of "defective coffee beans"

Enough to affect the flavor of 1kg of good coffee

This is really a case of "one bad apple spoils the whole barrel"

What are defective beans?

Here is the answer for you

The CQI green bean evaluation standard divides typical green bean defects into Category 1 and Category 2 according to their severity.

1. Major defects/first-level defects (Category 1)

Category 1 defects are absolutely not allowed in the CQI specialty coffee bean evaluation standards. They will seriously and continuously damage the quality of normal coffee beans, deteriorate the coffee flavor, and the coffee drinks produced will also be harmful to human health.

There are 6 Category 1 defects:

1. Whole black beans

Full Black

Impact: fermentation, foul odor, musty smell, sour smell, etc. (there is a risk of ochratoxin).

Cause: Agricultural problems, usually over-fermentation and microbial infection during the drying process.

2. Whole sour beans

Full Sour

Impact: Fermentation, stench, musty, sour, mainly depending on the degree of fermentation of the beans.

Cause of formation: This is mainly caused by microbial infection during the processing process.

3. Dried fruits/pods

Dried Cherry/Pods

Impact: fermented musty phenolic taste

Cause: In the washing process, the shelling is not good or the dried fruits are not completely removed during the water selection. In the drying process, it is caused by poor screening of coffee beans.

4. Moldy beans

Fungus Damage

Effects: fermented, foul, musty, earthy

Cause: The main reason for moldy beans is mold infection, which can occur at any time from harvesting to storage.

5. Foreign matter

Foreign Matter

Impact: Different negative flavors will be produced depending on the type.

Causes: Accumulated due to various reasons during processing.

6. Severely insect-infested beans

Severe Insect Damage

Impact: It affects the appearance of the roasted coffee beans and may produce dirty, sour, iodine or moldy smells.

Cause: Caused by coffee borers eating coffee beans in the orchard. Coffee grown at higher altitudes tends to have fewer borer defects.

2. Minor defects/Secondary defects (Category 2)

Category 2 defects are considered to be rare in the CQI specialty coffee bean evaluation standards, but they are still strictly controlled to avoid some sour beans, some black beans, and coffee beans with abnormal growth that can affect the flavor. Category 2 defects will also deteriorate the flavor of coffee, although not as serious as Category 1 defects, but some are more of an appearance defect that will also affect the selling price.

The following are 10 Category 2 defects:

1. Floating beans

Floater

Effects: Fermentation, grassy, ​​earthy and musty notes, which can make the coffee taste less flavorful.

Cause: This is caused by improper storage or drying.

2. Partial black beans/half black beans

Partial Black

Impact: fermentation, foul odor, musty smell, sour smell, etc. (there is a risk of ochratoxin).

Cause: Agricultural problems, usually over-fermentation and microbial infection during the drying process.

3. Partial Capers/Half Capers

Partial Sour

Impact: Fermentation, stench, musty, sour, mainly depending on the degree of fermentation of the beans.

Cause of formation: This is mainly caused by microbial infection during the processing process.

4. Shelled beans/parchment beans

Parchment / Pergamino

Impact: Indicates poor bean selection.

Cause: This is a defect caused by poor adjustment of the shelling machine.

5. Shell beans

Shell

Impact: It may produce a burnt smell when baking, and a large amount may cause uneven baking.

Cause: This is a natural phenomenon caused by genetic relationships.

6. Unripe beans

Immature/Unripe

Impact: Generally speaking, it has a grassy or strawy taste, and is also the main cause of astringency.

Cause of formation: The cause of unripe beans is mostly improper harvesting or uneven maturity of coffee berries in high-altitude coffee trees.

7. Shrinking Beans

Withered

Effect: Weed-like flavor, straw (depending on amount).

Cause of formation: The cause of shrinkage beans is mostly due to lack of water caused by drought during the development of coffee fruits. The degree of shrinkage depends on the duration and intensity of the drought.

8. Damaged beans/broken beans

Broken/Chipped/Cut

Effects: Dirty, musty, earthy or fermented smells.

Cause: Usually caused by problems with the machine when removing the pulp or shelling the beans.

9. Coffee husks

Hull/Husk

Effects: In sufficient quantities may produce dirty, earthy, musty odors.

Cause: Mainly due to equipment debugging or operational errors during the screening process.

10. Slightly Infested Beans

Slight Insect Damage

Impact: It affects the appearance of the roasted coffee beans and may produce dirty, sour, iodine or moldy smells.

Cause: Caused by coffee borers eating coffee beans in the orchard. Coffee grown at higher altitudes tends to have fewer borer defects.

Fermented/Foul/Corrupted Odor

Fermented/Stink/Rank

Impact: The fermentation smell is too strong, producing rotten fruit or high-concentration alcohol taste, or even metallic taste, which affects the flavor of the coffee.

Cause: The temperature is too high or the time is too long during the fermentation process.

Musty

Mouldy

Impact: Musty smell, affects the flavor of coffee.

Cause of formation: Moldy beans are the main factor causing musty smell.

Phenolic

Phenolic

Impact: Chemical taste, which can seriously mask the coffee flavor.

Causes: contamination during the processing step, failure to stir the food in time during the fermentation process, etc.

Old Bean

Old Crop

Impact: Cardboard smell, wood smell, stale smell, rancid smell.

Cause: Poor storage conditions cause the coffee beans to lose their activity, and the above flavors are produced after the fibers are roasted.

Isn’t it awesome that I found so many defective beans for you to see?