I wanted to make some ashed cheeses, but all local sources looked ridiculous - $30/jar for activated charcoal from the pharmacist! Then I found this idea: http://360degreescheese.wordpress.com/2011/11/28/homemade-vegetable-ash/
, and decided to give it a go. I live in an inner-city flat, so putting paint cans or coconut shells in the fireplace isn't really practical.
I used 1 onion, 1 carrot, 1 head of garlic, and a big handful of fat parsley stems, just as their picture shows. I charred the vegetable slices under my electric grill until almost
totally charred (I had to disable the smoke alarm, but the smell was actually quite nice). I stopped while there were still faint traces of colour and the pieces retained a shininess to them - my reasoning being that this would let me keep some of the tasty aromatic oils intact. I then dried the tray in a very low (100'C) oven until they felt totally dry and brittle, which took a few hours. And lastly, I ground the pieces in my little coffee/spice grinder (I had to do it in batches - add a handful, grind, add another handful, etc) until I had a fine black powder. The total yield was about 3 tablespoons of finely-ground ash.
I can definitely taste the vegetable origins when putting the ash directly on my tongue - the parsley & garlic particularly - it instantly makes me think of barbecued potatoes, char-grilled eggplant, etc. It's almost acrid when tasted alone, but accompanies acidic cheeses (chevre & a PC-semi-lactic so far) very nicely. I'm sure it could be made milder by omitting the garlic & parsley (maybe replace with celery & onion), and/or charring the pieces longer until they look dull/matte and totally blackened, but this suits me just fine for the cheeses I'm making at the moment.
I know that the white husk of young "drinking" coconuts is also used to make an edible ash (used for Thai sweets), but I have never tasted it and don't know if it's work with cheese. I think it would, and I'll give it a go some time, but I think my 3 tblsp is going to last for a while! I found this method for the coconut ash if anyone wants to try in the meantime: 1. For coconut ash, take a young coconut, cut the outer layers of husk off and arrange on a baking tray. Dehydrate in the oven at 100⁰C-120⁰C for 1-2 hours (careful not to colour) and husk is dry and brittle. Using a blow torch, burn pieces until they are black and crumble like breadcrumbs.
I also found this tidbit interesting: "As coconut doesn’t have any natural sugars or salt it doesn’t taste burnt but looks black."
I guess they're talking only about the husk here.
I used my ash to make a "salting mix" by grinding 1 part ash with 4 parts cheese salt using a mortar and pestle until very fine, then applied it to my cheeses using a little spice-shaker. This ratio was recommended by other forum members, and I used it because I like strongly-ashed cheese, but other people recommended ratios more like 1:20. The coffee grinder didn't grind it quite fine enough for my liking, hence this extra grinding step (it was also to mix it evenly with the salt). But it was still pretty fine - when using the ash straight, without salt, I simply put it through a little tea-sieve - this is also an easy way to apply it - and that was ok, not gritty at all.