Berkeley Hot Composting (18-Day Method) — FarmPal

The fastest composting method. Creates finished compost in 18 days through carefully managed high-temperature decomposition. Kills weed seeds and pathogens.

Time to Finish
18 days
Space Needed
Minimum 3×3×3 foot pile (1 cubic yard)

🟢 Greens (Nitrogen)

  • • Fresh grass clippings
  • • Kitchen scraps
  • • Fresh manure
  • • Green garden trimmings
  • • Coffee grounds

🟤 Browns (Carbon)

  • • Dry leaves
  • • Straw
  • • Cardboard (shredded)
  • • Wood chips (small)
  • • Dried corn stalks

Steps

  1. 1Build pile all at once minimum 1 cubic yard, 25-30:1 C:N ratio
  2. 2Shred all materials to 1-2 inch pieces for fastest decomposition
  3. 3Moisten to "wrung-out sponge" consistency (50-60% moisture)
  4. 4Days 1-4: Leave pile alone temperature should reach 130-160°F within 24-48 hours
  5. 5Day 4: Turn pile completely rebuild, re-moisten if needed
  6. 6Days 5-18: Turn every other day (days 6, 8, 10, 12, 14, 16, 18)
  7. 7Temperature should stay 130-160°F between turns
  8. 8Finished when temperature no longer rises after turning, dark, crumbly, earthy smell

Troubleshooting

⚠ Pile won't heat up
✓ Too dry (add water), too small (add material), or not enough nitrogen (add greens/manure)
⚠ Smells like ammonia
✓ Too much nitrogen add carbon (browns). Turn for aeration.
⚠ Smells like rotten eggs
✓ Anaerobic needs oxygen. Turn immediately and add dry browns for structure.
⚠ Temperature drops below 130°F
✓ Add nitrogen source. Ensure adequate moisture. May be finishing.

Tips

  • 💡Use a compost thermometer this is not optional for hot composting
  • 💡The 130-160°F range kills most weed seeds and pathogens
  • 💡Shredding materials is the #1 factor for speed
  • 💡In 2025, research confirmed hot composting destroys most pharmaceutical residues in manure