Biochar - can I just buy charcoal and grind it up?

From what I understand, biochar is the same substance as charcoal, just put to a different use. Can I just buy a bag of charcoal at the market, grind it up and spread it on my field? Most of the websites seem to be focused on how to make it, but charcoal is cheap and easily available where I am, so why not just buy it?

Yes. But you want to make sure that it is the "lump" charcoal and not the pressed briquettes. Lump charcoal sells at a bit of a premium to the briquette kind and doesn't have any fillers and binders. Briquettes can contain clays and glues that keep them from falling apart in the bag and making a lot of dust -- well, there is still dust, but not as much as a bag of the lump kind.

Store bought charcoal will also not be inoculated and it will suck nutrients if you apply it directly to plants. You want to soak it in some compost tea or manure tea overnight before applying it to the garden.

Really not a good idea to buy charcoal that is meant for burning and use it as a soil amendment. In addition to glues and fillers, some charcoal even has lighter fluid added to it. And if you're really unlucky, you could get charred coal, which is quite a bit different from biochar. This is the whole reason they use the prefix "bio".

That said, there are people who sell biochar that has been prepared for immediate use in the garden. And while your best results will come from burning in a fancy retort, I get decent results burning in a open fire pit until the coals fall apart easily when hit (at which point they almost ring) and then dousing with water.

You say that where you are located, charcoal is readily available.
But, you didn't say where you are located.

In the U.S., Canada, and much of Europe, "charcoal" as sold in the open market is often manufactured, rather than made. They take wood dust/chips/etc and produce "briquettes". These are not the same thing as is commonly produced in places like Mexico, Chile, or Haiti.

Charcoal "briquettes" are not suitable for 'bio-char'. As has been stated above, they are made with wood products bound together with glues/binders.'

However, if you live in a region where true 'charcoal' is made, that would be just fine. The down side to this is, however, that in many of those regions, living plants are being killed to produce cooking/heating fuels. This practice is not sustainable in some regions. For example, in Haiti, they have been using this plant material for so many centuries to cook with, that their half of the island is becoming a desert, despite the abundant rains. The soils are washing into the Caribbean with each rainfall. For the poor folks, it is cheaper to keep adding fuel to the fire 24 hours a day than it is to buy boxes of matches.

Here in the U.S., the most common brand of 'briquettes' is Kingsford. The company was founded by Henry Ford. He used old shipping crates and pallets to supply much of the the fuel needed to keep his foundries operating. He expanded his knowledge into making 'briquettes' from all of the shavings from the floor where wooden parts were being made. Despite his reputation(s) for other things, he was a cheap bastard that never let anything go to waste. He even designed (and built) a prototype auto that used hemp oil as fuel, and had hemp fiber coach works. He had 1,000's of acres growing hemp...he thought that that was the future of America. People more powerful than he saw otherwise.

I use a 55 gal barrel with lid to make biochar from the hardwood sticks and twigs that come from pruning and cleaning up dead fall on the farm. It has been said and repeated in this thread to not use briquettes. I've even made biochar from blackberry canes, we had millions of them when we bought the farm and now, 6 months of clearing later we still have thousands left to deal with. I know that Kroger in the USA has their own brand of Lump Charcoal, one thing I would watch out for when using the bagged variety of lump charcoal is the not completely charred pieces. The stuff I end up with is so done it is hard to get it out of the barrel with out it fracturing into small pieces. I have a kiddie wading pool that I use for inoculation of the material before it goes into the dirt.

Yes, but don't.

Most charcoal has other ingredients you don't want, but it is possible to find just plain hardwood charcoal - wood made warm until pretty much only carbon is left.
If you do manage to find pure hardwood charcoal, it will cost you a pretty penny.

Meanwhile, making biochar is comically easy and near-free.

I use a 55gal drum with a lid and three half-a-fist sized holes in the bottom. A smaller bucket/drum will work.

-Put up on a few bricks
-Add some wood, burn until mostly coals.
-Remove bricks so no more air comes up from the bottom.
-Add some more wood
-Let it burn down to coals
-Add some more wood
-Repeat until you have as much as you want
-Douse with water till it stops steaming on contact
-Cover

Works poorly making charcoal you want to burn later - it's all wet.
Works great for biochar.

You can buy lump charcoal and use it. but piss on it first or soak it in manure tea or even add some urea to it. Adding a high N manure to the char will neutralize the PH you may want to add other anion containing materials too.

If making your own char you can add some extra ashes which may reduce the production of lighter polymers which are more harmful. By adding ashes you may reduce the polarization frequency and also get a product with less sulfur content.

The add at the bottom is basically plain old charcoal with no additives. It is made with slow pyrolysis which is good but the add doesn't say they added any nutrients so you wouldnt want to use that straight. you would have to mix it with manure. If you put it with manure in a pail of water for a month you will get anaerobically altered forms of nitrogen and they are time released by aerobic microbes and such. You may want to aerobically activate these new compounds.

If you have a Trader Joe's store near you, check out their bbq briquettes. They advertise them as 'made from sustainably raised hardwoods, and containing only cornstarch as a binder. You can use the ashes in your garden!" Plus, price is around $8 for 18 lbs. Probably inferior to 'professionally/commercially" produced biochar... but adequate to the job?

I believe them, and am 'crushing', soaking in golden elixir, etc., and mixing with soil in planting holes. Now, I'm wondering if I can just 'innoculate' the briquettes and bury as is... ??... crushing is tedious ;)

UPDATE !!- crushing is exhausting! But I just soaked some in 'liquid', and guess what... they DISINTEGRATED overnight! (All that work ... no 'crushing' necessary!) Apparently the ONLY ADDITIVE in these, the natural cornstarch, dissolves readily. Wow!

Also, another idea, do some research on 'bentonite clays' as a soil additive ... apparently good CEC for nutrient and water retention; recommended by Elliott Coleman. Sodium Bentonite absorbs 15 times or more water; used to line ponds, drilling holes, etc., and is 'clumping' cat litter; calcium bentonite absorbs only about 2-3x water, is non-clumping cat litter. Feed stores often sell them at best price. Plus, you can make a water emulsion to add it to your soil.
http://www.plantsman.com.au/page2/files/Plantsman%20Adding%20clay.pdf

Btw, I obviously have sandy soil and no irrigation system... and if our latest summers here are any indication, water is going to be the limiting factor in our climate chaos.

nancy sutton wrote: I obviously have sandy soil and no irrigation system... and if our latest summers here are any indication, water is going to be the limiting factor in our climate chaos.

Not to get too off topic here, but if you are looking for cheap sources of clay, try glossy paper. Coated paper used for magazines and junk mail advertisements is about 1/3 clay and 2/3 wood pulp fiber. If you put your old magazines in the biochar kiln and char the pages black, you will end up with clay incorporated biochar which will be a great amendment for sandy soil. I've done that, and the only caution is you need to stack them so the sheets are vertical, not horizontal. Flat sheets act as insulators and it takes a while for the heat of the kiln to get to the center of the pile; if the sheets are vertical, the gases and the char front are moving in the same direction and it proceeds much better.

Hey John I getting even farther off topic but, I wonder if I could use those clay papers to seal a pond we have very bad seepage where I live do you think its wprth a shot?

Jeff R Hodgins wrote:Hey John I getting even farther off topic but, I wonder if I could use those clay papers to seal a pond we have very bad seepage where I live do you think its wprth a shot?

You'll only find out if you do some experimenting. I'm no expert on the permeability of clays, and am a little mystified by the gleying process (which is akin to using clay papers). I think for my pond purposes, I want to be a little more sure of its integrity, that's why I'm leaning more to a swimming pool plaster type of formulation. But I haven't gotten very far along with that project and if you have some success with clay papers, maybe that's something I could consider.

I do have a nice parged block tank it never leaks but it only holds like 1000-2000L for like $150-$200. The problem is that I need like a billion litres to wet my 5 acres for 6 months a year.

I see my suggestion is gone, but I don't know why. My point was that all bbq briquettes are not the same...most brands do have awful binders, and Kingsford is probably the worst, and most ubiquitous (does Kingsford advise use of their ash in the garden?) If if you do some research, you will find that there is variety in the additives/glues etc used to bind them.

However, I believe that if.... IF... the advertisement, that I quoted, for this store's house brand briquettes is accurate, then they might be an adequate, non-toxic, affordable, form of charcoal, to be inoculated into biochar. (I.e., cornstarch isn't typically toxic.)

Many of us do not have a kiln, nor the $ to purchase commercial, perfectly pyrolized, biochar - especially when a comparable option may be available .... cheaply. And I think biochar may be too valuable to be limited to those who do. (I personally think this particular store is particularly trustworthy, btw. Was it mentioning the store's name that got me booted?) We sub/urban gardeners are 'small potatoes', I suppose, compared to folks with acreage, but we are numerous!! and the more (non-toxic) biochar that gets into the soil, the better...I thought, anyway ;)

Re: sealing a pond, you might want to google 'NW Edibles' where Erica Strauss ( a friend of Permies.com) has gone into great detail explaining how she used the right form of bentonite, mixed with soil, to make her duck pond. She explains how she tested the clays, the mixes, etc., complete with photos and happy ducks :) Granted, this is a small suburban pond, but she did a lot of leg work, in her typically thorough fashion ;) Plus, I found that local feedstores do carry sodium bentonite (aka 'clumping' cat litter), but they didn't know it by it's scientific name. (Btw, Elliott Coleman recommends bentonite clay as a soil amendment, referring to German studies showing benefits.)

And I'm in Western Washington, between Seattle and Tacoma - maritime, with 'mediteranean' summers ;) ... I think it is under my name... ?

(OK, I did some more research.. the charcoal in question is the Rancher brand of 100% Natural Charcoal, made by The Original Charcoal Co., repackaged for the unmentionable ... apparently... store's brand. It is made from coppiced hardwoods grown in Latin American.. with cornstarch as a binder.)
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Update (4/17) just fyi -- last spring, (3/16) I went to Trader Joe's to get more of their 'natural' BBQ briquettes, only to discover it is no longer sold! They now sell another product, not labeled 'natural' , and at a significantly higher price. Glad I stocked last year : )

on top of all this has anyone asked, does biochar work? The studies I've seen independently show mixed result so I'd love to know if anyone has taken a scientific approach over the course at least a few years and concluded that biochar works? If there is another thread on this site that answers this question please let me know.

Brad Cloutier wrote:on top of all this has anyone asked, does biochar work? The studies I've seen independently show mixed result so I'd love to know if anyone has taken a scientific approach over the course at least a few years and concluded that biochar works? If there is another thread on this site that answers this question please let me know.

I am convinced that it does, both by reading the research and what I have seen in my garden. If you want to read the scientific research, the best place to start is with Johannes Lehmann. He is a professor of agronomy at Cornell University and the leading researcher into the study of biochar. Here is a link to one of his recent review articles.

Brad Cloutier : O. K., But remember you asked !

U.S. Schools doing research - - Cornell, Univ. of Fla., Rice Univ., Univ. of Colorado, Also Germany's Potsdam Univ., and U.K.s Univ. of Edinburgh
Generally these all have multiple positive findings !

Wikipedia Lists ( 66 ) notes for their article, and a separate Research References listing of of 17 articles and several links to other
leading Sites !

For the good of the Crafts ! Big AL

Mother Earth News has an article on their website on a way to make it yourself. And a very analytical home gardener in our climate, whom I know personally, has found it helpful in his garden. Another local proponent is Art Donnelly of SeaChar.

Ok. We all understand the difference between lump charcoal and charcoal briquettes.

I've been considering a workflow to incorporate bio char into my garden. In my area (affluent suburbs) I can't really get away with making my own biochar on a regular basis due to neighbor concerns over smoke, etc. However, running a bbq is perfectly acceptable.

Also, I don't want to purchase lump charcoal for the sole purpose of applying it to the garden, and I certainly don't want the extra work and dust of grinding it up. So here's what I have come up with:

* purchase lump charcoal, this could be from a local vendor or the grocery store
* use only the larger chunks of charcoal in my grill- anything smaller than thumb size, including dust/fines, goes into a storage bin
* this will make grilling better (small chunks of charcoal reduce airflow in the grill) and will net me about 1/4-1/3 of each bag of charcoal in small bits and fines
* in my worm composting tray system, I will throw a scoop of the stored charcoal bits and dust in with each new tray of compost
* this "activates" the charcoal, charging it with beneficial bacteria and nutrients from the compost, so that when applied to the garden it won't temporarily "rob" the garden of nutrients as would happen if you applied pure charcoal to the garden
* this also locks up the charcoal dust into the soil, ensuring that it won't blow around and become a health hazard

Any other ideas for how to integrate bbq charcoal and gardens?

In reference to Nathan's comments, thank you for being succinct within this discussion. I use lump charcoal and I crush it with a large tamper of the variety use to compact paving substrate (you can get this at Home Depot/Menards/Loews, etc. not expensive and handy to have for many reasons). After crushing one large bag I simply add it in multiple doses to my compost bin. the result is inoculated biochar/compost that is perfect for amending soil. i usually ad it to the compost as I add my green material to be composted in equal volumes. i keep a bucket of the crushed lump charcoal next to the compost bin to keep it handy for addition. This also has the added benefit of locking a lot of the compost nutrients in the charcoal until I'm ready to spread the compost.

Great comments Nathan and Rednaxela! For those who want to know, biochar has been around for probably over a thousand years, it can be found in ancient sites both in the Andes, Ireland and Scotland/England. If you live in California and go up into the Sierra Nevadas, there are some forest burn areas from the 1960's where Mother Nature decided biochar was needed, those areas are very rich in flora now. Bio char works just about anywhere in the world, it was usually used in ancient times where the soil was very sandy and needed help in retaining water to grow plants for food for humans.

You really don't want to use charcoal intended for cooking. The process for making the charcoal is different and there is a substancial difference in what you're getting.

Lump charcoal (I won't even get into briquettes) is loaded with tars and creosotes. This is where the smoky flavor comes from. Well made biochar has cooked all of those chemicals out.

When you make charcoal you are heating up organic woody material in a low oxygen environment, (there are thousands of different ways to do this). The low oxygen environment allows for processes that wouldn't happen with oxygen because the wood would simply burst into flame. So...you apply heat to wood with limited oxygen, the "volatile compounds" will "gassify" into flammable gases and liquids. While the stable portion, the carbon to carbon bonds that make up the structure of the wood will stay intact. This is the charcoal. Biochar is free of volatiles and will have no taste or smell and you can crush it between your fingers without any oily residue. Traditional lump charcoal allows the volatile compounds to redeposit into the pure carbon. Lump charcoal is often much denser than biochar because most of the pore spaces are full of those tars. Many of these volatiles are toxic and will negatively effect your plants.

Now that this is clear as mud...do a google search for a double barrel retort or the Kon Tiki kiln to learn how to make your own biochar.

Thank you Matt- that was the clearest explanation I've heard yet as to why lump charcoal is actually fundamentally different from biochar. I'll evaluate and adjust my process based on your input.

Matt, why is the dry double barrel method not just like bagged lump charcoal? If it tinkles like glass it obviously has a high carbon content indicative of a high temperature burn. I imagine some are not, and I make my own low temp charcoal in my own smokers before throwing out the BBQ and I know that the higher levels of organic material that give smoky flavor also dull the glassy sound. The reason I ask is that the Kon Tiki article mentioned quenching as a method of partial charcoal activation, but I have learned to watch out for the european mentality that would be so focused as to seem to allude to a unique function such as activation, when in fact that is what generally happens anyway, but perhaps not to the same degree? The reason I ask is that so far the one reading I have under my belt that specifically mentions charcoal activation mentions the use of either sodium chloride or zinc chloride and I got the impression this was a second post char step, and seemed like a lot of bother.

Thanks Matt... Now having read that excellent description, I have 2 questions... 1. I'm guessing because lump charcoal was not water quenched or cooked to the proper "doneness" it does not have the higher surface area that allows it to take in microbes, is that a correct statement? And 2. Does anyone have any actual results, negative or positive, from using lump grilling coal in the fashion described above... Over time that is..?

Anyone else notice how similar the ingredients to a good active biochar are to black powder / gun powder?

Ryan, could you elaborate a little bit?

So I wonder can you finish lump charcoal to biochar. I understand all the reasons for not using lump charcoal, as it still contains the oils and possible toxins, and does not have the same surface available for the biochar. I hoping to use lump charcoal to get my burn going...seems ok, but hope get validated from someone.
Thanks

As a starter, using a few briquettes doesn't sound so bad.  The oils and wood still in them should burn off, as long as you monitor it until the right time.  You would still have the steps of getting it to be the right size, which often includes crushing, and charging/inoculating it with something nutritious, before it's actually biochar.

Some people had bought commercial charcoal and used it directly instead of biochar, which is not a good strategy for many reasons.  

John S
PDX OR

Matt Banchero wrote:You really don't want to use charcoal intended for cooking.  The process for making the charcoal is different and there is a substancial difference in what you're getting.  

Lump charcoal (I won't even get into briquettes) is loaded with tars and creosotes.  This is where the smoky flavor comes from.  Well made biochar has cooked all of those chemicals out.  

When you make charcoal you are heating up organic woody material in a low oxygen environment, (there are thousands of different ways to do this).  The low oxygen environment allows for processes that wouldn't happen with oxygen because the wood would simply burst into flame.  So...you apply heat to wood with limited oxygen, the "volatile compounds" will "gassify" into flammable gases and liquids.   While the stable portion, the carbon to carbon bonds that make up the structure of the wood will stay intact.  This is the charcoal.  Biochar is free of volatiles and will have no taste or smell and you can crush it between your fingers without any oily residue.  Traditional lump charcoal allows the volatile compounds to redeposit into the pure carbon.  Lump charcoal is often much denser than biochar because most of the pore spaces are full of those tars.  Many of these volatiles are toxic and will negatively effect your plants.  

Now that this is clear as mud...do a google search for a double barrel retort or the Kon Tiki kiln to learn how to make your own biochar.  

This is good info. I just went and double checked the charcoal I bought for my little urban garden. It's an "organic" brand, claims to be 100% wood, the pieces are dusty but not oily. I think I'm on the safe side. It's really not worth making charcoal myself for the tiny quantities I need.