How to make your own wood vinegar with a Cookswell Kiln

How to make your own free wood vinegar and Stockholm tar with the Cookswell Smoke Trap and a Kinyanjui Kiln.  (Avalible from

What is wood vinegar? 

Recovery of chemicals from the vapours given off when hardwood is converted to charcoal was once a flourishing industry. However, as soon as the petrochemical developed, wood as a source of methanol, acetic acid, speciality tars and preservatives became uneconomic. But with the advent of higher prices for organic food and organic living, wood vinegar is making a vigorous  globally resurgence.  

Wherever charcoal is made the possibility of recovering by-products should be discussed.

By adding a simple metal pipe to a large 140$ Cookswell drum kiln - you can collect appx. 1-2 liters of wood vinegar per 9 hour cycle while producing appx. 20-35kgs of lumpwood charcoal from appx.80kgs of air dried wood. 

Wood vinegar is another name for pyroligneous acid and is the crude condensate of smoke that consists mainly of water. 
The non-water component consists of wood tars, both water soluble and insoluble, acetic acid, methanol, acetone and other complex chemicals in small amounts. When left to stand, the pyroligneous acid separates into two layers comprising the water insoluble tar and a watery layer containing the remaining chemicals.

Simple decant it into bottles and let the tars settle for 12 weeks or so. 

Specific Farm Uses for Wood Vinegar:

The Appropriate Technology Association of Thailand recommends the following wood vinegar/water solution rates for various farm uses:

• Repel nematodes – Tomatoes, 1:500 (apply to the base of plants); strawberries, 1:200 (apply to the base of plants); and black pepper vines, 1:1500 (apply in place of water).

• Repel insect pests – Cabbage and Chinese cabbage, 1:1500 (apply in place of water); corn 1:300 (spray onto leaves).

• Control of fungal diseases – Tomato and cucumber, 1:200 (spray onto leaves).

• Control of root rot – Tomato and cucumber, 1:200 (apply to the base of plants).

• Reduce incidence of chili pepper flowers aborting – 1:300 (spray onto leaves).

• Improve flavor of sweet fruits and stimulate development of crops. Mix solution rates of 1:500 to 1:1000. Wood vinegar prevents excessive nitrogen levels, improves plant metabolism and contributes to higher fruit sugar levels.

• Stimulate compost production. A solution rate of 1:100 will help increase the biological activity of various beneficial microbes and can decrease composting times.

• Combat bad odor. A wood vinegar solution of 1:50 will diminish the production of odor-causing ammonia in animal pens.
• Supplement for livestock feed. Mixed with livestock feed at rates of between 1:200 and 1:300, wood vinegar can adjust bacterial levels in the animal digestive tract which improve the absorption of nutrients from feed.

• Enrich garden soil. Use a strong solution of 1:30 to apply to the garden soil surface at a rate of 6 liters of solution per 1m² to enrich the soil prior to planting crops. To control soil-based plant pathogens, use an even stronger rate of application. 

Composition and Characteristics of Wood Vinegar

Nikhom reports that wood vinegar yield per metric ton (2200 lbs.) of air dry wood is appx. 314 kg (690.8 lbs.). The product contains approximately200 components. 

These include:
• Alcohol (methanol, butanol, amylalcohol)
• Acid (acetic, formic, propioinic, valeric)
• Neutral substances such as formaldehyde, acetone, furfural, valerolactone
• Phenols (syringol, cresol, phenol)
• Basic substances such as ammonia, methyl amine, pyridine

He also describes quality wood vinegar as having the following characteristics (most of which may require special laboratory instruments
or methodology to determine):
• pH of approximately 3.0
• Specific gravity between 1.005-1.050
• Color ranging from pale yellow to bright brown to reddish brown
• Transparent
• Smoky odor
• Dissolved tar content: less than 3 percent
• Ignition residue: less than 0.2 percent by weight

Your own homemade wood vinegar will vary depending on the feedstock used, moisture content and carbonization time. We recommend you do trials before large scale use.

A 2 hour cooling phase of the kiln before extracting the lumpwood charcoal

Wood vinegar and charcoal making during de-bushing for pasture improvement. Another by product is Stockholm tar for the cattle and horses hooves. 

And with many thanks to Kenya - we are also including a packet of indiginous acacia xanthopholea and kirkii tree seeds so you can grow a life time supply of free woodfuel, wood vinegar, biochar and tar.

For more information about wood vinegar - please see these links below:

Please get in touch with us at if you have any suggestions, comments, questions or would like to pick some up for a trial for free!


  1. Some more links here below:

    ''Students from the RMUTL Pitsanuloke campus developed a charcoal kiln in order to produce charcoal from small fallen branches of nearby trees. During the process of making charcoal, the kiln was designed to produce wood vinegar as a by-product. Use of wood vinegar is becoming popular with some Thai farmers who make use of this cheap source of organic liquid as a plant protection substrate. The experiment examined wood vinegar, produced by the student-designed kiln, as a fungicide, bactericide and as either laying or hatching inhibitor of cowpea weevil. The results suggest that wood vinegar is a promising solution in plant protection, showing good potential for inhibition of pathogenic-fungi and bacterial growth. It was found that cleaning wood vinegar by sedimentation or centrifugation is necessary. Sedimentation of wood vinegar for 3 months resulted in similar characteristics to commercial products. Furthermore, centrifuged wood vinegar could prevent egg laying and penetrated well into the seed of cowpea weevil. These results indicated that people in rural communities could easily build or modify their own charcoal kilns in order to produce wood vinegar for use as an organic method of plant protection for their farms.''

  2. And this from

    ''Until recently, charcoal and wood vinegar have been used
    principally in areas other than agriculture. Charcoal has
    been used as a fuel, of course, as well as in sewage treatment
    and metal polishing. Wood vinegar has been used in a
    variety of ways, including as an ingredient in medicines, an
    additive to animal feeds, a deodoriser, a mordant in the
    dyeing process, a facilitator in the fermentation process, a
    filter in sewage treatment and a raw material in various
    other industries.
    However, recently farmers and agricultural researchers
    have been looking into the use of charcoal and wood vinegar
    as alternatives to chemicals in improving crop yields and
    controlling pests. According to recent research and field
    trials, the following are some of the benefits of using wood vinegar in agriculture.

    Benefits of wood vinegar
    Wood vinegar has a variety of beneficial effects
    stemming from the fact that it is made up of a variety of
    minerals, compounds and acids. Researchers have
    found that wood vinegar consists of more than 200
    different ingredients. Tables 1 and 2 show the main
    ingredients found in raw and refined wood vinegar.
    The most common component in wood vinegar, except
    for water, is acetic acid, which accounts for 3 to 7% of
    the total ingredients and 50-70% of the organic matter.
    In addition to acetic acid and other organic vinegars,
    raw wood vinegar also consists of roughly 5% phenols
    and several percents of various types of alcohol
    including methanol and ethanol.
    Researchers have found that the beneficial effects of
    wood vinegar in agricultural applications include:
    1. Spraying diluted wood vinegar on plant leaves
    increases their vitality and improves crop quality.
    2. Spraying also helps control harmful insects and
    some kinds of plant diseases.
    3. Wood vinegar and agricultural chemicals are
    complementary. The efficacy of using them together
    is greater than using either one alone.
    4. If wood vinegar is applied to the soil or mixed into it
    in high concentrations, it inhibits eelworms and soil
    diseases. In low concentrations or while it is in th
    process of being broken down in the soil it increases
    the quantity of useful microbes.
    5. Wood vinegar helps plants develop stronger roots.
    6. Mixing wood vinegar with manure reduces odours
    and facilitates composting.
    Wood vinegar has a variety of other benefits. For example, if
    it is mixed with animal feed, it improves the meat quality.
    Table 1 lists some specific uses of wood vinegar in
    combating blight and insects.
    How wood vinegar is formed
    In order to better understand the components of wood
    vinegar ad how it works, it may be helpful to know how it is
    formed. The main ingredients in wood are the fibres
    cellulose, hemicellulose and lignin (Figure 3). In addition
    there are small quantities of compounds such as tannin.
    When these compounds are pyrolysed, ie in an air-tight
    environment, new compounds are formed. The types of
    compounds formed depends on the temperature of the fire.
    During the wood carbonization process, cellulose first
    pyrolyses at about 275 degrees centigrade. Later, lignin
    pyrolysis begins at 375 degrees, becoming most intense at
    400 degrees (Figure 4). (The same type of process occurs
    when compost is made from straw where decomposition by
    microbes first occurs in the cellulose and later in the harder

  3. Hi

    My name is Felicity from South Africa, I am more interested in a charcoal manufacturing kiln tha can produce approximately 1000 5kg bags a day. How much will that costs, & what will be the levels of airpollution compared Kyoto standards of poluution, if they are higher, how can they be mitigated.


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