Background
What is an LCA?
An LCA is an acronym for life cycle assessment. A life cycle assessment or cradle to grave analysis is a systematic method used for evaluating the life cycle of a product, or service. The evaluation generally includes but is not limited to: a list of all inputs and outputs, an energy analysis of all the upstream materials used, and the environmental impacts.
The Coffee Cycle
Growing
A coffee bean from a coffee tree is planted in soil. Within 4 to 8 weeks a seedling appears. The seedling is placed in a shaded location so it will not burn in the direct sunlight. The seedling is tended and allowed to grow for the next 9 to 18 months, until it reaches approximately 2 feet. The small coffee tree is planted in the ground. The tree will bear fruit in 3 more years, but does not reach maturity until 6 years. At 6 years the tree is fully mature and produces it's optimal yield. The coffee tree will produce for 20 to 25 years.
Transportation
Roasting
Brewing
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. The process is known as brewing. Brewing of coffee is done to extract the coffee flavor and caffeine from the roasted coffee beans. The coffee grounds are never boiled with water because this process imparts a bad flavor to the cup of coffee.
There are three distinct methods of brewing coffee: steeped, boiled, and pressurized.
Steeped coffee is conventionally done in a french press. A french press is a cylindrical device made of glass that contains metal plunger filter that fits tightly in the glass cylinder. Hot water and coffee are placed within the french press and allowed to brew for 5-10 minutes. The plunger is then pressed down separating the coffee grounds from the coffee solution. The steeping process makes a stronger cup of coffee because the coffee grounds remain in contact with the hot water longer. The longer the hot water stays in contact withe the ground the more of the flavor and the coffee oils are extracted from the coffee grounds.
Boiling coffee is the oldest known brewing technique. Boiling coffee was traditionally done by placing coffee grounds and water into a pot and boiling it. The coffee was not boiled for long as this would taint the flavor. The liquid was poured into a cup and consumed. The liquid would generally contain some coffee grounds, but the majority of the grounds would be at the bottom of the pot.
Pressurized coffee brewing generally has two sources of pressure: gravity pressure and pressurized water.
Gravity pressure brewing is more commonly known as drip coffee. Drip coffee is by far the most common method of brewing in the USA. A filter is filled with coffee grounds and hot water is slowly allowed to flow through the coffee grounds. Gravity causes the hot water to flow down through the coffee grounds. The liquid drips out of the filter and is collected in a container and consumed.
Pressurized water brewing is more commonly known as espresso. A mechanical device heats and pressurizes the water and forces the hot water through some coffee grounds. The coffee that is brewed using this method uses more coffee grounds per ounce of liquid coffee than any other method.
Consumers
Coffee Grounds
After brewing a cup of coffee the coffee grounds remain and must be disposed of. The three common disposal methods are: solid waste, waste water, and recycled.
Coffee grounds that are placed in the trash end up being shipped to some regional dump.
Coffee grounds that are washed down the drain are transported via waste water in the sewer lines to the waste water treatment plant. At the waste water treatment plant the grounds are separated out and treated according to that particular treatment plants protocols.
Coffee grounds that are recycled are usually composted or used to amend the soil for plants. Composting the coffee grounds enriches the nitrogen content of the compost. Because of the coffee grounds individual small size, it breaks down and composts relatively fast. When the coffee grounds are used as an amendment to the soil, the grounds slowly release nitrogen and add acid to the soil.