Principles of Coffee Making

Coffee is made by dissolving ground coffee beans in hot water to extract the flavours. The essence of making good coffee is to extract just enough of these solids to make a flavorful beverage, but not to brew for so long that the coffee becomes bitter. With this in mind, consider the following guidelines for making good coffee. The list is lengthy, and each item is significant.

  1. Use fresh coffee.
    Coffee quickly loses flavour and aroma once ground. To keep coffee fresh, keep it tightly sealed in a cool, dry place. Even with the best storage, you should not use coffee that is more than a week old. Although vacuum-packed coffee lasts longer, it deteriorates as soon as it is opened. If you can’t grind your own coffee every day (as some restaurants do), you can at least arrange for frequent delivery.
  2. Use the right grind and the right brewing time.
    A coarse grind requires more time for extraction than a fine grind. You must use the grind that is suited to your equipment.
    Grind Extraction Time
    Fine or vacuum 2 to 4 minutes
    Drip or urn 4 to 6 minutes
    Regular (percolator) 6 to 8 minutes
  3. Use the right proportions.
    Always take measurements. Depending on the strength desired, 1 pound of coffee and 134 to 212 gallons of water, or 500 grammes of coffee and 7.5 to 10.5 litres of water, is recommended. After removing the used grounds, add more hot water to make a weaker coffee. Using more water during the brewing process lengthens the brewing time, resulting in over extraction and bitterness. Many experts believe that passing no more than 2 gallons of water through 1 pound of ground coffee (8 litres to 500 grammes) and then diluting to taste is the most effective way to avoid bitterness. Coffee strength is a matter of customer preference and varies from region to region. For example, people in New York generally prefer stronger coffee than people in Chicago. In some areas, the preferred ratio is 1 pound (500 g) coffee to 3 gallons (12 liters) water.
  4. Use fresh water.
    Fresh, cold water brought to a boil contains dissolved air. Water that has been kept hot for an extended period of time does not, so it tastes flat and produces flat-tasting coffee. Tap water is usually the best option. For tap water that has off flavours or is heavily chlorinated, special filtration systems are available. Do not use softened water that has been chemically treated.
  5. Use water at the right brewing temperature: 195° to 200°F (90° to 93°C). Water that is too hot extracts bitter solids. Water that is too cold does not extract enough flavor and yields coffee that is too cool for serving.
  6. Use a good brewing procedure.
    Most operations use either urns, for large volume, or automatic drip makers, which make one pot at a time, as shown in the photograph. These machines can make excellent coffee because water passes through the grounds only once. Percolator-type coffee makers should not be used. They boil the coffee as it is being brewed and pass it through the grounds repeatedly.
  7. Use clean equipment.
    Urns and coffee makers must be cleaned every day. Coffee leaves oily deposits that quickly turn rancid or bitter and that can ruin the next batch of coffee.
  8. Use good filters.
    Good filters are the only way to ensure sparkling, clear coffee. Most operations use paper filters, which are discarded after use. If cloth filters are used, they must be perfectly clean and free from odors.
  9. Use proper holding procedures.
    The ideal temperature for holding is 185° to 190°F (85° to 88°C). Higher temperatures decompose the coffee quickly. Lower temperatures result in cold coffee for the customer. Carafe-style coffee makers typically keep coffee warm over electric burners. Do not leave brewed coffee on the stove for more than 30 minutes. After this time, there is a significant loss of quality. If it needs to be kept longer, transfer it to preheated thermos containers as soon as it is brewed. Produce coffee in such a way that it is always fresh. Throw out old coffee.