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KNF Brew Calculator.

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KNF Brew Calculator

Korean Natural Farming brews: FPJ, FFJ, OHN, IMO, LAB, WCA. Material weights, brewing times, dilution rates.

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grams of plant / fruit / source material

What KNF is

Korean Natural Farming (KNF) is a method developed by Cho Han Kyu (대한 자연 농업, Cho's Global Natural Farming) that emphasizes using locally available materials and indigenous microorganisms to feed plants and build soil. It's deeply biological — focused on cultivating plant-friendly microbes, hormones, and enzymes from materials you can ferment yourself.

Its principles overlap with regenerative agriculture, biodynamics, and other living-soil approaches. KNF is OMRI-compatible when source materials are organic. It emerged from Korean farming traditions but has been adopted globally, particularly in Hawaii (where it's heavily used in tropical agriculture) and increasingly in cannabis cultivation.

The brews, in order of common use

BrewSource materialBrewing timeUse
FPJ (Fermented Plant Juice)Young plant growth — dandelion, alfalfa, mugwort, comfrey, etc.5-7 daysPlant growth promoter; rich in plant hormones; foliar or root drench
FFJ (Fermented Fruit Juice)Ripe sweet fruit — apple, banana, persimmon, melon5-7 daysSugar/K source; flowering/fruiting boost; dilute foliar
OHN (Oriental Herbal Nutrient)Angelica, ginger, garlic, cinnamon, licorice3 months+Plant immune-system tonic; pest deterrent; fungal suppression
LAB (Lactic Acid Bacteria)Rice wash water + milk culturing5-7 days + 7 daysMicrobial inoculant; probiotic; soil + foliar; odor reduction
WCA (Water-soluble Calcium)Eggshells + brown rice vinegar14-21 daysPlant-available Ca; foliar or root drench
WCP (Water-soluble Calcium Phosphate)Roasted bones + brown rice vinegar14-21 daysP + Ca; flowering/fruiting boost
IMO (Indigenous Microorganisms)Wild collection (forest leaf litter) on rice → expansionsMulti-stage (weeks)Soil microbial inoculation; foundation for other living-soil work
JA / JMS (Jadam Microbial Solution)Leaf mold + boiled potato + sea salt + water1-3 daysQuick microbial brew; alternative simpler approach

FPJ — Fermented Plant Juice (most common)

Materials

  • Young, vigorously growing plant material — collected at sunrise (highest plant energy)
  • Equal-weight or 1:1 brown sugar (or jaggery, molasses)
  • Glass jar with breathable cover (cloth + rubber band; no airtight lid)

Process

  1. Collect plant material in early morning before dew evaporates
  2. Chop coarsely; do NOT wash (you want the indigenous microbes on the plant)
  3. Layer plant material with brown sugar, equal parts by weight, in a glass jar
  4. Press down lightly; cover with cloth or breathable cover
  5. Store in cool, dark place 5-7 days
  6. Liquid drains from the plant material; this is FPJ
  7. Strain; store in cool dark place; can be refrigerated for months

Use

  • Foliar: dilute 1:500 to 1:1000 in water; spray
  • Soil drench: dilute 1:1000; water in
  • Use during growth phase; switch to FFJ for flower/fruit

A note on quality

KNF brews are biological products — quality varies by source materials, environmental conditions, and brewing technique. Watch for:

  • Pleasant, slightly fermented smell = good FPJ / FFJ
  • Rotten, putrid smell = brew failed; discard
  • Active bubbling = healthy fermentation
  • White surface mold on FFJ is generally OK; black/colored mold = discard
  • Pink film on LAB during culturing = bad; restart

Maintain clean glass containers, source materials from healthy plants, store away from direct sun.

Free under CC BY 4.0. Cite as "OAT KNF Brew Calculator (openagriculturetechnology.com)". Methods from Master Cho's "Korean Natural Farming" and translation references.