I frequently find golf ball-sized rocks in bags of lump charcoal. Usually after the fire has burnt out.

Is this some by-product of the charcoal manufacturing process or an under-handed attempt by the manufacturer to cheat on the weight of the bags?

  • 1
    In searching for the episode I mentioned, I found someone with a site reviewing charcoal, and they also mentioned golf ball sized rocks (but that once removed, it was still over the advertised weight): nakedwhiz.com/lumpdatabase/lumpbag57.htm
    – Joe
    May 25, 2022 at 0:55
  • 5
    1% rocks = 1% profit.
    – Richard
    May 25, 2022 at 14:02
  • 8
    @NotStandingwithGoGotaHome you need better charcoal in that case - you shouldn't be getting that stuff in there
    – Chris H
    May 25, 2022 at 18:04
  • 2
    @Joe There's also an episode of How It's Made where they make charcoal out of coconut husks. While the process is somewhat more involved, there's no rocks involved there either. May 25, 2022 at 18:23
  • 1
    I have this same problem, except with dried beans (and the rocks are much smaller, obviously).
    – Michael
    May 27, 2022 at 19:04

2 Answers 2


I've often seen small stones in charcoal, and it makes sense.

Charcoal is often a byproduct of logging, made from lower quality wood such as branches and thin growth at the top of trees. During felling and trimming, this will lie in the dirt while the more valuable wood is dealt with. Then it will be picked up by machinery, loaded, and taken away to be burnt into charcoal. Some contamination from soil is inevitable, and that will include a few stones as well as smaller stuff that adds to the dust in the bottom of the bag. Even treestumps can be used, and digging those out is also likely to bring some soil with them.

  • 2
    It can also be that the charcoal is stored on the ground after production, loaded to the small bag packer with a frontloader. In either case, I'd avoid that particular supplier.
    – Stian
    May 26, 2022 at 9:20

When buying lump charcoal (which is my preference) I've found that the brand is really important. Some of these producers are sourcing their wood from worksites or other potentially contaminated locations. Keep an eye out for dimensional lumber, for example. You probably don't want charcoal made from pressure treated lumber. But it can get far worse: PVC, metals, and other debris can find it's way into the bag.

In my preferred brand, I have found an occasional rock. Generally, they are roughly the size and shape of a piece of charcoal. While I'm annoyed to pay charcoal prices for a rock that I don't need or want, the quality of the rest of the charcoal is very good. This leads me to think that this is not intentional but just part of ramping up production. I don't think people are looking at every log or stick that's going into the 'cook'. They are probably scoping up wood with a front loader or some sort of large claw and some rocks are picked up inadvertently.

I would keep an eye out for things like plastic but a few rocks are part of the cost of using lump charcoal, IMO. If you are getting a lot of contaminants in your charcoal, look for another brand. Where I live, the smaller hardware stores and butcher shops have the good stuff.

  • 12
    I'm guessing that with "better" brands, they run the charcoal through sieves so that only appropriate sized chunks pass -- large debris gets filtered out on the first pass, then small stuff falls through on the second pass... but rocks roughly the desired size of the charcoal make it through such processes, which is why these particular sizes of rocks show up.
    – Doktor J
    May 25, 2022 at 21:19
  • @DoktorJ Seems like a reasonable hypothesis.
    – JimmyJames
    May 25, 2022 at 21:30
  • It seems like there are two brands available here, but I haven't really shopped around for others. I've never found any dimensional lumber or other "impurities". Finding one or two stones isn't unusual in my experience, but this bag I'm working on now is working up to a couple dozen.
    – gnicko
    May 25, 2022 at 23:07
  • 3
    @gnicko : these days, the best way to get something fixed is probably to take a picture of the pile of rocks with the bag, and post it on Twitter. Especially if they have a presence there
    – Joe
    May 25, 2022 at 23:32
  • If this wasn't for cooking, I would say to balance contamination with price
    – user253751
    May 27, 2022 at 12:34

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