Gravity causes the hot water to flow down through the coffee grounds. A filter is filled with coffee grounds and hot water is slowly allowed to flow through the coffee grounds. Drip coffee is by far the most common method of brewing in the USA. Gravity pressure brewing is more commonly known as drip coffee. Pressurized coffee brewing generally has two sources of pressure: gravity pressure and pressurized water. The liquid would generally contain some coffee grounds, but the majority of the grounds would be at the bottom of the pot. The liquid was poured into a cup and consumed. The coffee was not boiled for long as this would make the coffee taste bitter. Boiling coffee was traditionally done by placing coffee grounds and water into a pot and boiling it. The longer the hot water stays in contact with the grounds, more of the flavor and coffee oils are extracted from the coffee grounds.Д«oiling coffee is the oldest known brewing technique. The steeping process makes a stronger cup of coffee because the coffee grounds remain in contact with the hot water longer. The plunger is then pressed down separating the coffee grounds from the coffee solution. Hot water and coffee are placed within the french press and allowed to brew for 5-10 minutes. A french press is a cylindrical device made of glass that contains a metal plunger filter that fits tightly in the glass cylinder. Steeped coffee is conventionally done in a french press.

There are three distinct methods of brewing coffee: steeped, boiled, and pressurized.

The coffee grounds should not be boiled with water because this process imparts a bad flavor to the cup of coffee. Brewing of coffee is done to extract the coffee flavor and caffeine from the roasted coffee beans. In order to make a cup of coffee, the coffee beans must first be ground down to the proper consistency and then boiling hot water is run over them. Figure 4 shows coffee berries being moved to the processing plant where they will be de-husked and dried.ДЇigure 4: Coffee berries being transported from the fields to the processing facility. Leaving the plant, coffee is shipped mostly with boats and trucks. At the plant, coffee is trucked from the field and between processes. A large portion of coffee production costs and emissions come from its transportation. The roast flavor is so dominant that little of the original flavor is able to be tasted.Д¬offee is grown all over the world and shipped to most of it. The flavor of the darker roast is characterized by the 'roast' flavor. The darker roast coffee is shinier than the light roast because the heat extracts the oils from the inside of the bean. The longer the coffee is roasted the darker the color of the bean at the end of roasting. The original flavor is reminiscent of the soil and climate the coffee was raised in. The flavor of the lighter roast is characterized by the coffees original or raw flavor. The less time the coffee is roasted the lighter the color of the bean at the end of roasting. The length of time of roasting significantly impacts the flavor of the coffee. The temperature of the roaster ranges anywhere from 188 to 282 degrees Celsius.

The coffee is roasted anywhere from 3 to 30 minutes depending on the desired outcome (Figure 3). After the coffee has been sorted it is weighed into batch size and placed within the roaster. Д¬offee roasting starts with sorting the beans from the debris that is mixed in with the beans. Therefore roasting takes place just before selling to the end user. The green coffee bean is stable for much longer. The destabilized coffee will remain fresh for about a month. When the green coffee bean is roasted chemical reactions take place that enhances the flavor and also destabilizes the coffee. Coffee is roasted to bring out flavor.Д¬offee is roasted to enhance the flavor of the raw or green coffee bean. Figure 3: A typical coffee roasting facility.

Travel mug life cycle analysis