What kind of material would be most ideal to enclose grains/legumes to smash?

Question

Here's some background on my question, before I actually ask it (my question is in bold below):

I'm wanting to have a very sustainable method of turning grains, legumes and pseudocereals into flours (which methods do not require electricity or reliance on corporations in the long run). In the short-term, I don't mind purchasing some materials. A variety of methods have come to mind:

1. Grinding with rocks. This is essentially like using a mortar and pestle. It works (I tried it with some club-like rocks I found in Kentucky), but most mortars and pestles that you can actually buy are very small, and unlike the sorts they might use in the East for grinding larger amounts of flour (wherein the pestle is like a meter long or such)—I haven't seen these available in the USA (that's where I am). Using rocks doesn't seem to work very well for larger, harder things like chickpeas, but it's very effective for millet, and works okay for rice and wheat. It's easy to squash the wheat, but requires further grinding if you want more than squashed wheat.

2. Using a hammer or mallet. I tried this on chickpeas and it works fine. I assume it works for other legumes, grains, and pseudocereals, too (although it may or may not be the most practical solution for tiny seeds like millet). Lacking a mallet, I could always use rocks to smash (rather than squish and grind them as with a mortar and pestle) them. I have a blacksmith hammer on order to try for this purpose, since its broadness should smash more seeds at a time.

3. Using a manual grain grinder. This is all well and good, but they may be a lot more difficult to make yourself (and might lead one to be reliant on others to get the grinder). Plus, really good ones are very expensive.

4. Making a huge animal-powered stone mill like they used to use. This would probably be rather effective and ideal, but I'm looking for a simple solution that doesn't require animals or things so large (and one I can tote around with me if I travel).

Anyway, my question pertains to item number 2 (using a hammer/mallet/rock to smash them). I basically want to get a very broad mallet, and a sack that won't break if I hammer it (I want to put the grains/legumes/pseudocereals inside the sack and hammer them until they're flour; the sack is to keep them in place while I hammer them). So, my question is, what kind of materials would be suitable for this sack? I don't want it to break apart when I hammer it (like the experimental paper I used with the chickpeas did).

I thought about leather. That sounds like it could work, but would it be treated with stuff that would make the flour toxic? Would leather be strong enough? Would something else be more ideal?

I'm also thinking about just using some old jeans or something to make a grain-smashing pouch. Maybe that would work.

Edit: I recently had the idea that if I'm just looking for something that I can do right now, with purchased materials, I can always just buy a packet of socks, and when one wears out, use another one, heh, heh. Socks are pretty inexpensive, but they would make me reliant on sock companies, probably.

Answer 1

Mallets/Sacks

I think you're going down the wrong track with the sack idea. I doubt any kind of fabric or material that could be used to make a sack would stand up to much hammering, and even if it did I would also expect that if your end goal is flour then using a mallet would not give a quality result. If you wanted rolled oats for porridge, you might just be ok though. My understanding is that successful crushing of grains/seeds requires two hard (and generally heavy) objects, not just one. Improvising, while travelling, to find the second of those objects might be a bit dicey unless perhaps you're happy to hose down a section of concrete and use that. Even then, the owner of it may be upset if it was stained or damaged.

Alternatives

Ultimately, unless you want to meditate on the inefficiency of crushing/grinding grains manually, I think you would be best to invest some money in an electric mill and use the time you save pursuing other admirable sustainable goals. To make it more sustainable, you could purchase second hand, choose a model that has replacement parts available, ensure it's a good quality effective device, share it with your local community, and sell it on when you no longer use it.

Electricity/Corporations (TL;DR?)

You mention electricity and corporations as something to be avoided. Many people with that belief would have a sudden change of heart when faced with difficult decisions such as whether to receive urgent healthcare using a vehicle to get to a hospital or relying on a pigeon to request the local herbalist ride his horse to your place at a gallop.

I admit that I can see it being a very big challenge for our society to continue to embrace technology and yet become truly sustainable for the long term, but I doubt that shunning technology such as electricity will do us any better. Shunning corporations, where possible, seems like a pretty good idea though as they are substantially responsible for nurturing a greed-focused, polluting, unequal culture.

Answer 2

Milling by hand is very hard work, that's why most traditional mills are animal, wind or water powered. I have used a commercially made hand-powered grain mill, and it was very hard work. A cup of flour took a minute or more of fairly strenuous work (I cycle and use a power meter, so I'm guessing more than 150 Watts which is a lot of arm power - it's the effort most adults and apply to a bicycle using their legs, for example)

The little ones are basically jokes as far as I can tell. You could make one loaf of bread occasionally, sure, but they're not designed to accept much power in, so they're going to be very slow.

(from Amazon)

Something like this is what I used, and you can get both hands onto the handle plus use your core muscles for power. It also bolts to the table or stand rather than using a flimsy clamp. It's faster, but still not something you're going to feed a 20 kilogramme sack of wheat through. Not in one day, at least. However, you can convert one of these to use leg power (basically hook it up to an exercise bike) and that makes it less impractical. But those cost more, use more space, and if you're not certain you will use it, likely to be hard to resell.

(via Modern Survival Blog)

Doing the same thing with rocks, or by beating cloth covering rocks, doesn't strike me as very practical. If you were milling small amounts of seeds (what most people use a mortar and pestle for), it might work. I just can't imagine a cloth rugged enough not to wear out very quickly. And since you're going to be grinding the cloth as well as the seeds, you'll be eating the cloth. So whatever cloth you use, be willing to eat it.