A kitchen compost bin is an indoor collection system used to temporarily store food scraps before they are transferred to a larger, outdoor composting pile, a municipal collection service, or a vermicomposting system. This container is designed for short-term use, typically holding a few days’ worth of material. Its primary function is to conveniently divert organic waste from the regular trash stream, making the process of reducing household waste easier and minimizing trips outdoors to a main compost site.
Selecting the Right Container Style
Container selection depends on how quickly you plan to empty the bin and your preference for handling moisture. The three main styles for indoor collection are sealed, ventilated, and Bokashi systems, each having distinct requirements for a do-it-yourself project. Sealed containers, such as a simple repurposed plastic tub or ceramic crock with a tight-fitting lid, are the easiest to start with and are best for users who empty their scraps daily or every other day. These non-ventilated bins minimize odor by containing it, but they require the most frequent emptying to prevent anaerobic bacteria from developing foul smells.
Ventilated containers are designed to allow air exchange, which helps manage moisture and slows down the decay process, making them suitable for collecting scraps for three to five days. This style often involves modifying a plastic container or metal pail by adding holes, promoting the aerobic decomposition that is less odorous. The third option is a specialized Bokashi system, which uses an airtight container and a microbial inoculant (bran) to ferment the waste anaerobically. Bokashi is a distinct process that does not require ventilation and can handle materials like meat and dairy, but it needs a specific container with a spigot to drain the resulting liquid fertilizer.
Building Your DIY Kitchen Composter
The most common and effective DIY method for a kitchen compost bin is creating a ventilated system from an inexpensive plastic storage container or metal pail. To begin this project, you will need a few basic tools: a drill with a small drill bit, a hot glue gun, and a piece of fine nylon mesh or screen material. The container should have a tight-fitting lid to ensure pests cannot access the contents, even with the added ventilation holes.
The modification process starts with the lid, which is the primary site for air exchange in a countertop model. Use the drill and a small bit (1/8 to 1/4 inch) to create five to ten evenly spaced holes across the lid’s surface. After drilling, a screen must be secured to the underside of the lid to keep fruit flies and other small insects out while still allowing air to pass through freely.
Cut the nylon mesh or screen material slightly larger than the area covered by the drilled holes. Use a hot glue gun to firmly attach this screen to the inner surface of the lid, completely covering all the ventilation holes. For enhanced odor control, some builders opt to incorporate a piece of activated charcoal filter material between the lid and the mesh, as the porous carbon structure absorbs odor-causing compounds. Once the glue is dry and the screen is secure, the modified container is ready.
Operational Management and Odor Control
Effective management of a kitchen collection bin centers on balancing the input materials and maintaining a regular emptying schedule. Acceptable “green” materials include fruit and vegetable scraps, coffee grounds, and crushed eggshells, which are rich in nitrogen and break down quickly. Scraps to avoid are cooked foods, meat, bones, dairy products, and oily substances, as these items will rapidly become putrid and attract pests in an indoor setting.
A common challenge in kitchen collection is managing the high moisture content of food scraps, which can lead to unpleasant smells caused by anaerobic conditions. To combat this, always layer your wet food scraps with dry, “brown” materials like shredded newspaper, torn-up cardboard, or sawdust to absorb excess liquid. This addition of carbon-rich material helps maintain a healthier environment for aerobic microbes and reduces the likelihood of a soupy, stinking mess.
The most practical step for odor management is frequent emptying; an indoor bin should be transferred to an outdoor system every two to three days, regardless of how full it is. Between uses, the container should be thoroughly washed with warm, soapy water to remove any lingering residue that can harbor bacteria. For additional neutralization, a sprinkle of baking soda or a charcoal filter placed inside the lid can absorb odors, but these methods are secondary to balancing moisture and emptying regularly.