Composting has become more popular in recent years, as people are more aware of recycling and environmental issues, even down to trying to compost their charcoal BBQ waste.
Composting is the method in which waste matter is converted into usable, mineral-rich compost through microbial activity. Typically, this involves digging a pit, making a pile, or using a compost bin and introducing food scraps, small twigs, grass, and other organic materials. The material is kept covered for several weeks. In time, bacteria will act upon this organic matter and increase its NPK (Nitrogen, Phosphorus, Potassium) ratio and make it usable as manure. Sometimes, worms such as earthworms can be added to the compost to speed up the process. When that is done, the process is known as vermicomposting.
Most people with a garden will attempt to at least compost household waste and garden refuse, but keen BBQers may be unsure whether or not the ashes of a charcoal barbecue are suitable for composting.
Composting Charcoal BBQ Ash
Charcoal is the product of burned wood, with a few other additives. As wood ash is compostable, this is also true of other wood products, including charcoal. There are two conditions to this, though. First, the charcoal itself should be basic wood. Beware of preservatives and other additives to make the product 'burn,' as these may not be environmentally compatible. For example, some charcoal burns the wood, leaving only a ‘binder’ chemical as the ash that is not suitable for composting.
The second condition is that wood ash itself may only be used in composts to a limited degree—around one cup per foot of compost—as large amounts of wood result in a loss of nitrogen in the soil. As with wood ash, only use a similar cupful of ash for each foot of compost. So long as you don’t barbeque every day, however, charcoal BBQ ash is perfectly safe to put into your compost pile or bin.