Black Soldier Fly Larvae (BSFL) Composting for Beginners

Turn food waste into high-protein chicken feed with this simple, natural system.

What is BSFL Composting?

Black Soldier Fly Larvae (BSFL) composting is a method of breaking down food scraps using the larvae of the black soldier fly (Hermetia illucens). These larvae rapidly consume organic waste and convert it into two valuable outputs:

1. Larval biomass – a protein-rich feed for chickens, fish, or reptiles

2. Residual frass – a nutrient-dense compost byproduct for soil amendment

Unlike earthworms or microbes in traditional composting, BSFL can digest higher-fat, higher-protein scraps without issue. They also do it faster, making this an efficient and low-odor option for managing food waste.

Why BSFL Composting Works for Gardeners

BSFL composting is especially useful for:

• Home gardeners with excess organic waste (like food waste and yard trimmings)

• Backyard chicken keepers seeking a sustainable feed supplement

BSFL thrive in hot climates, need minimal maintenance, and naturally self-harvest when mature, making the system nearly hands-off once set up.

Key Vocabulary

• BSFL (Black Soldier Fly Larvae): The larval stage of the black soldier fly, used in waste processing and animal feed.

• Frass: Insect waste and leftover material; high in nutrients and used as a soil amendment.

• Self-harvest: A system that allows larvae to crawl out when mature without manual collection.

• Zoning: Local regulations that govern the use of composting systems or keeping of live insects/animals.

How BSFL Composting Works

1. Larvae are introduced to a container filled with food waste.

2. They consume the waste rapidly, up to twice their weight daily.

3. They mature within 2–3 weeks under optimal conditions.

4. They self-harvest by crawling up a ramp and into a collection bucket.

5. You collect the frass and use it in your garden.

6. Mature larvae can be frozen or dried for chicken feed.

What Can You Feed BSFL?

BSFL are more flexible than worms but still need a balanced diet. Acceptable inputs include:

• Fruit and vegetable scraps

• Bread, rice, and grains

• Cooked leftovers (without too much oil or salt)

• Dairy (small amounts)

• Meat and fish scraps (in moderation)

• Coffee grounds, eggshells

Avoid:

• Excess oil or grease

• Processed snacks or sugary foods

• Bones

• Large citrus quantities (too acidic)

• Pet waste

Overloading your bin with spoiled or heavily salted food can attract pests or slow down decomposition. Always start with small amounts and observe.

Setting Up a BSFL Bin

You can purchase a BSFL bin or build one yourself. Key design features:

• Ventilation for airflow

• Drainage for excess liquid

• Ramp system for self-harvest

• Shaded, warm location (ideal: 80–100°F)

• Secure lid to deter pests and odors

Place the bin at least 10 feet from your home or garden. Use a food-safe, non-leaching container (avoid treated wood or reused chemical drums).

Safety Precautions

• Wash hands after handling larvae, frass, or feedstock

• Avoid raw feeding of larvae to chickens if scraps included meat, dairy, or fish (cook or dry them first)

• Control moisture, excess water creates anaerobic (oxygen-deprived) conditions that attract flies

• Freeze harvested larvae before storage or feeding to ensure they’re safe and inactive

• Keep the bin sealed to prevent rodents or houseflies

• Label clearly if used in a school garden - this is an active system, not a play structure

Using BSFL as Chicken Feed

Mature BSFL are:

• 50% protein

• Rich in calcium

• Naturally low in pathogens when fed clean scraps

Feeding methods:

• Feed fresh (immediately after collection, ideally after quick rinse or freeze)

• Feed frozen or dried (store up to 6 months in freezer or dehydrate in sun/dryer)

• Mix with other grains or food scraps as a protein supplement

Do not rely solely on BSFL; they are a supplement, not a complete feed. Chickens benefit most when BSFL are part of a diverse, balanced diet.

Garden Use of BSFL Frass

Frass from BSFL is high in nitrogen and chitin, a compound that helps plants resist pests. Use it as:

• Top dressing for garden beds (½ inch layer)

• Additive to potting mix (up to 10%)

• Compost accelerator (mix into traditional compost)

Let frass rest for 3–5 days before applying, especially in sensitive crops, to stabilize nutrient release and pH.

Zoning and Legal Considerations

BSFL are legal to raise in most U.S. municipalities, but always check local:

• Zoning codes – Backyard composting is usually allowed, but some HOAs or cities restrict keeping live larvae or feeding animals waste-based inputs.

• Animal feed laws – If you're selling eggs or meat, regulations may restrict the use of insects fed on post-consumer waste.

• School restrictions – In K–12 settings, confirm with administration before introducing insects or food waste handling on campus.

When in doubt, start with a small indoor system (desktop-size) to build awareness before scaling.

Common Mistakes to Avoid

• Using the wrong insects – Don’t confuse BSFL with housefly larvae (maggots); BSFL do not bite, sting, or spread disease.

• Letting it get too wet – Leads to odor, anaerobic decay, and mold.

• Overfeeding – Food should be eaten within 24–48 hours. Remove leftovers if not consumed.

• Lack of drainage – Liquids build up and suffocate larvae. Add drainage holes and collect leachate separately.

• Skipping pest-proofing – Rats and raccoons love food scraps. Use a secure bin.

Tips and Tricks

• Attract wild BSFL by setting out a bait bucket in warm weather. They’ll lay eggs near the food source.

• Keep ants out using water moats under your bin legs.

• Add shredded cardboard to absorb excess moisture.

• Use diatomaceous earth around the base to deter pests (not inside the bin, as it can harm larvae).

• Store harvested larvae in reused containers (like an empty bulk yogurt container) in your freezer—label clearly.

Final Thoughts

BSFL composting is a smart, scalable solution for gardeners who want to close the loop on food waste and chicken feed. Whether you're a home grower or a garden coordinator, this method provides a powerful teaching tool, a waste reduction strategy, and a low-cost protein source.

With proper setup and management, BSFL can transform your kitchen and garden waste into productive, regenerative outputs without the mess or smell of traditional composting.

For warm regions, especially the southern U.S., BSFL offer one of the most efficient and resilient waste management solutions available at the home scale. Need help getting started? Look for local BSFL suppliers, extension office demos, or school garden pilot kits that include larvae and ready-to-use bins.