Uses of spent ground coffee
WHEN COFFEE is brewed for consumers to enjoy that great cup, a potential nuisance is left behind. This substance known as coffee grounds, the remains of the ground coffee that are left over after the coffee is brewed, is generally discarded.
Because of their carbon content, spent grounds, as they are referred to, can produce methane and carbon dioxide, both of which are greenhouse gases that can contribute to global warming.The coffee-brewing process takes place at high temperatures, which sterilises the coffee while it is being brewed. The resulting ground that is produced is relatively a clean waste material, making it useful in enhancing processes that require a sterile source of raw material.
Coffee utilises large quantities of nutrients for its growth, development of quality characteristics.
This makes the spent ground a very nutrient rich material with the potential to be used as a value added resource in a number of processes.
ALTERNATIVE USES OF SPENT GROUND
1. COMPOSTING Given their high nutrient levels spent grounds is a suitable source of low cost composting. This include vermi-composting or natural composting with the grounds combined with other organic materials. The resulting nutrient rich product can be used to enhance soil nutrients and provide valuable micro-organisms. 2. MUSHROOM GROWTH The sterilisation carried out during the brewing process makes the spent ground a very sterile material and a medium that is suitable for the growing of mushrooms.
There have been many reports pointing to the use of spent ground coffee as a growth medium for mushrooms with great effect.
Studies from Australia indicate that Oyster mushrooms are the most suitable for cultivation on spent grounds, with the resulting mushrooms having no caffeine traces.
3.BIOACTIVE COMPOUNDS
It is well documented that coffee beans contain classes of health-related chemicals in the form of phenolic compounds among others.
Even though the brewing process causes sterilisation, the process only results in partial extraction of the phenolic compounds, therefore, spent grounds are a potentially valuable source of bioactive compounds with a wide range of applications for the food, pharmaceutical, and cosmetic industries.
Indications are that industrially these processes are not yet being actively pursued on any large scale.
The diagram above is certainly not exhaustive and so there is room for the continuous evaluation of possible uses of spent ground.
As you enjoy your brew today, be reminded of the contribution of coffee not only to your palate’s satisfaction but also to your wellness and the environment.