Stehouwer offers the following troubleshooting suggestions for cold, stinky compost bins:
• Mix the carbon and the food scraps more thoroughly, so the decomposing food can diffuse oxygen faster than it consumes oxygen.
• Mix more dry leaves or paper into a pile that may be too wet. “The rate of oxygen diffusion through water is 10,000 times slower than through air,” he said.
• “Add material that will help create porosity,” he said, such as wood chips, straw and dry leaves. Large air gaps in a compost pile improve air flow and help the microbes do their job.
• Add more carbon. Excess nitrogen, or food scraps, can generate stinky ammonia.