Page 3 - Coffee Basics Brochure SCAE - English

Wetting
The grounds begin to absorb the hot water from the sprayhead and release gasses from the coffee. For consistent extraction from all parts of the coffee grounds, the entire bed of coffee must be evenly wet in the first 10% of the brew cycle time.
Extraction
The water-soluble materials dissolve and move out of the coffee grounds and into the water. The best flavors are extracted at the beginning of the process as seen in the Brew Cycle Time table.
Hydrolysis
Through this chemical reaction, the materials created during extraction break down further into water soluble proteins and sugars.
High Solids
(Best avor and least bitterness)
Average Solubles
(Least acids)
Low Solids / Low pH
(Most bitterness and astringency)
BREW CYCLE TIME
1st Phase
2nd Phase
3rd Phase
MATCH THE GRIND TO BREW TIME
The brewing or water contact time with the coffee grounds is primarily determined by the grind size and bed depth. A longer brew time is required for the water to penetrate the larger grind particles. The recommended brewing contact times for each grind size are shown here.
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General Guidline: The finer the grind, the shorter the time.
Brewer Cycle Timing
The brew cycle delivery time of a coffee brewer assists in determining the recommended coffee grind to produce a quality cup. Experimenting with a coarser or finer grind will help operators discover the preferred coffee flavor profile.
Bed Depth
The ideal depth of the coffee bed in the brew basket is 2.5 - 5.0 cm regardless of the volume of brew. If a coffee bed is less than 2.5 cm, the water may move through it too quickly and under-extract. Water moving too slowly through a bed depth of more than 5.0 cm may cause over-extraction and a bitter taste.
THE SCIENCE OF THE BREWING PROCESS
Solids in the Brew
During the brew process
the water-soluble materials (solids) dissolve and move out of the coffee grounds and into the water. The level of solids changes while brewing, effecting the flavor, color, body and aroma of the coffee.
Brew Time
1st Phase
2nd Phase
3rd Phase
This is why coffee should never be served before the brewing process is completed! All three phases combine to produce the ideal flavor.
High Solids
Best avor and least bitterness
Average Solubles
Least acids
Low Solids / Low pH
Most bitterness and astringency
TASTE