Analysis of the phenomenon of coffee over-extraction the normal extraction rate of coffee the extraction time of coffee

The data show that there are only 30% extractable substances in coffee.

According to the international SCAA test, the gold extraction rate is 18% and 22%.

Factors: pressure (bar), strength of cake pressing

Ratio of water to powder (powder quantity)

Temperature (water temperature)

Extraction time

Freshness of beans (baking degree)

Now most of the products are produced according to the standard:

9barpare 20-30s extract 30ml (±5ml)

Coffee powder is generally not excessive extraction, it should be insufficient extraction, there is another situation is the wrong size of the bean grinder, although there is too much powder, but the flow rate is so fast that excessive extraction is also to see whether the freshness of beans and the coffee machine is normal.

Excessive extraction

If the crema is dark brown and has white spots

There is a black hole in its center.

Too much coffee powder

Grinding particle size is too fine

The extraction temperature is too high

Pump pressure is too high

Incorrect filling and compaction

The coffee temperature is low.

The temperature is below 78 degrees.

The coffee cup is too cold

The filter is overcooled when the tray is filled.

Grinding particle size is too fine

Insufficient amount of coffee extraction

Insufficient extraction

Crema is lighter in color.

The consistency is very low

Insufficient amount of coffee powder

The abrasive grain is too coarse.

Pump pressure is too low

The coffee machine temperature is too low.

The extraction is moderate but the coffee cup is cold.

Incorrect filling and compaction

Foul-smelling coffee

The coffee is out of date

Unclean devices (coffee bean container, grinder, espresso coffee maker)

There are deposits at the bottom of the coffee cup.

Pressure is too high

The filter screen and the packing plate are fouled and worn.

Place the nozzle on the dirty surface when mashing the coffee powder

Blade wear of bean grinder

Apron wear

There is stagnant water on the surface of coffee pressed powder after extraction.

The extraction temperature is too high

Separation network pollution

Insufficient amount of coffee powder

Grinding particle size is too fine

The extraction drain valve may fail.

The output water temperature is too low.

Uneven flow rate of double cups

The Espresso coffee machine is not flattened

Filter screen pollution

Coffee powder is not flattened.

Nozzle scale

Source: network