How to separate ash from char after a burn?

My char production is rather rudimentary. I light an open campfire, let it burn down to coals, then I quench with water until it stops boiling/steaming.

While I get a fair amount of char to turn into biochar, I also create a fair amount of ash.

My current process involves 'washing' out the ash from the char and then shoveling the char up into a container when it is fully cooled. The ash ends up accumulating in a low spot near the original area of the fire in the lawn.

While this works all right, it is rather water intensive and I'm unsure if there is a better way out there?

Thank you in advance for your thoughts.

Sifting or winnowing perhaps?

Which floats more, ash or biochar?

Maybe after the quench, shovel into a metal bucket and see?

This guy uses a metal kitty-litter scoop...

Hardware cloth, 1/4" works well.

Also why not mix the ash in with the biochar and compost?

M Ljin wrote:Also why not mix the ash in with the biochar and compost?

Ash raises the PH very quickly and to much is worse than to little! Far as I know the char is fairly neutral and the ash may be well over 9.

Something you folks should realize and you may already. Is that when you wash ash you're making lye.

I try to make as little ash as possible for that reason. We have acidic soils, so some ash is good.

Do you all realize how much calcium is in hardwood ash?

Better yet do y'all have any idea how much better ash is for improving soil over lime? Not just for raising PH but for the full balance. It contains somewhere over 150 minerals and elements / supplements!

Think of char or charcoal as a sponge and safety lockbox combined. It sucks up all sorts of stuff and often locks bad things in while letting good things out at a slow metered rate.

Look up and study terra preta.

Diversity is the real key to great soil!

Always make slow incremental changes no big burning changes!

There are many reasons why I try to maximize biocjar and minimize ash. Ash helps but it doesn't last as long as biochar. Biochar has more volume. Biochar helps mycelium more. Biochar doesn't shift ph as much. Biochar helps retain moisture and improve drainage.
John S
PDX OR

While Tim specifically asks about sifting, would you consider minimizing ash by burning then dousing the biochar in a burn pit?
By making a small fire in a pit, then covering it with layers of sticks to partially smother the burn, I am able to carefully douse the fire from the bottom up while the new layers of char continue to burn on top. There is little to no ash in this process.
I mostly follow this excellent video by Manuel Angerer with this small modification: instead of dousing the fire completely, just add water to the bottom of the pit while keeping the upper layers burning. When finished with the burn, douse the entire pit as shown in the video.
After years of avoiding biochar due to concerns of adding alkalinity to my highly alkaline sandy soil, I am very pleased with this minimal ash method.

Amy Gardener wrote:While Tim specifically asks about sifting, would you consider minimizing ash by burning then dousing the biochar in a burn pit?
By making a small fire in a pit, then covering it with layers of sticks to partially smother the burn, I am able to carefully douse the fire from the bottom up while the new layers of char continue to burn on top. There is little to no ash in this process.
I mostly follow this excellent video by Manuel Angerer with this small modification: instead of dousing the fire completely, just add water to the bottom of the pit while keeping the upper layers burning. When finished with the burn, douse the entire pit as shown in the video.
After years of avoiding biochar due to concerns of adding alkalinity to my highly alkaline sandy soil, I am very pleased with this minimal ash method.

I don't even consider burning in a pit in my yard because I can't. I live in a suburb. They've already called the fire department on me.  There are no open spaces that are far from other people's properties.  It would be illegal and the fire department would cite me.
John S
PDX OR

We are small scale, 1/4 acre in town.  Our char making is done in a metal, lidded pot in our Chofu which heats the water for our outdoor soaking tub.  So anytime we are heating the tub for soaking, the last 10 mins before we get in, the pot of 'hardwood' goes into the chofu and pyrolizes.  Once cooled, that charcoal goes into either the chicken run or the goat pen for inoculation before it goes into the garden.  Very little ash is created.  Certainly nothing to attempt to sift out.

I think you would be better off finding a way to make more char and less ash rather than working on sifting minimal char from ash.

From my understanding True char is formed in the abscence of oxygen…. And I don’t that is the same as partially burnt wood

I agree with you in general, Mark Beard, but I would say that char is made in a limited oxygen environment.

John S
PDX OR

I just hate answers that come from "googling" but in this case, I think many are so polite in their suggestions, that perhaps some of the more convincing suggestions are not coming forth.

So with that in mind this link will give you lots of insite-   https://biochar.international/guides/biochar-reactor-to-meet-needs/

with your ultra small scale ( nothing wrong with that ) and the WANT for less water, it would seem to be answered on the above site.  But for me it boils down to same size fire. a pot with lid,  and way more char with far less water.

Best of success.

That's a great site, Scott.  So much information!

John S
PDX OR