vintage garden charcoal, can I charge and use it?

I recently got several lots of garden stuff from the estate of a pair of orchid breeders.
One of the lots had this old bag of garden charcoal.
It seems to be the right size for charging and looks like it is pure wood charcoal.

Should it be fine for me to go ahead and charge and use it?

I have trees that are getting planted in the next couple of weeks and it would be great to add some to their planting holes and I'm not fully set up to make my own yet.

Cool find!

A standard test for charcoal is to rub your hands with it and see if the black rinses off with water (no soap). This tells you if the char has been fully cooked and the volatiles and tars burned off.

But it's only 3 litres. Personally I would use it.

You could try to break open some of the briquettes. If you see wood inside, you know it's not biochar.  Biochar is very light in weight. It also makes a musical tone when it bounces or is struck.  Biochar crushes down if you try. Wood charcoal probably won't.  

If you make biochar, you could add it to your burn and the wood, tannins, and oils should be gone when your burn is done. Then it is biochar.

John S
PDX OR

It does wash off with just water.

It isn't briquettes. It's small, aquarium rock sized, bits of carbon. It is very light and crushes easily.

It might be the real thing! Now I'd say that I would probably also just use it.

John S
PDX OR

I had no idea that charcoal was part of the magical orchid soil mix. This is completely new. These guys have been flying under the radar!