THE ELEMENTS OF BREWING PERFECTION

WATER

Fresh, good-tasting water is essential since it makes up more than 98 percent of a cup of coffee. Mineral content can affect taste. For best results, water should not exceed these parts per million

(ppm) of dissolved minerals:

• Ideal – 50 -100 ppm (50-100 mg/L) or 3 to 6 grains of hardness

• Acceptable – Below 300 ppm (300 mg/L) or 18 grains of hardness

Brewing perfect coffee starts with clean equipment. Make sure your brewer is free from any contamination or odors that might affect the coffee.

TIME

The brewing time or the time water is in contact with coffee grind determines the amount of coffee material extracted, the major component affecting flavor.

TURBULENCE

Turbulence is created as the water passes through and over the coffee. It should cause the particles to separate and create a uniform flow of water around them for proper extraction.

FILTRATION

Paper filters produce the clearest cup of coffee. BUNN filters are:

• Porous enough to allow free flow of the extracted coffee solubles.

• Made from oxygen processed paper for best coffee flavor.

• Strong enough to prevent collapsing.

TEMPERATURE

The temperature of the water during brewing affects flavor and extraction.

• Ideal Water Temperature – 195º - 205ºF (92º - 96ºC)

Combining these elements for optimum flavor, productivity and profit is a science, a science that BUNN has been exploring for over 40 years.

THE SCIENCE OF THE BREWING PROCESS

Understanding the brewing process is essential to controlling the qualities that create the ideal coffee drinking experience.

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, you must evenly wet the entire bed of coffee 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.

Bed Depth - The ideal depth of the coffee bed in the brew basket is 1-2 inches (2.54-5.08 cm). If your coffee bed is less than 1 inch, the water may move through it too quickly and under-extract. Water moving too slowly through a bed depth of more than 2 inches (5.08 cm) may cause over-extraction and a bitter taste.

Brewer Cycle Timing - Your equipment's brew cycle delivery time assists in determining the recommended coffee grind to produce a perfect cup. Experiment with a coarser or finer grind to attain the flavor profile you prefer for your coffee.

The brewing or water contact time 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.