The question, posed by Ken Albala. Why doesn’t the “West” grind wet? That is why didn’t they soak or boil grains before they ground them?
As a preliminary I would say that they would certainly have tried it. If you look back at the past, everything that could be done to grains was: toasting, sprouting, soaking, boiling, adding alkali (and doubtless acids too), pounding, grinding, doing these things in diverse orders, fermenting the result, shaping the result.
Second preliminary. People were very, very picky and knowledgeable about the result. If you depend on grain (bread, tortillas, boiled rice, etc etc) for 80% of your calories you become a connoisseur of grain products. We simply don’t match that knowledge.
Third preliminary. Grinding and pounding sound simple but they were very sophisticated operations with dozens of variants depending on the species of grain, the variety of the species chosen, the age of the grain, the type of grindstone (dozens of shapes and materials of lateral grindstones alone) and the preliminary treatment of the grain before you started.
Fourth preliminary. Our vocabulary is ridiculously restricted. How many of us today can snap our fingers and explain the difference between meal and groats and grits and flour and grist and a whole complex vocabulary that varied from place to place and grain to grain. Just the word bread covers a world of products and that’s only the beginning.
Fifth preliminary. This may all seem just too nerdy for words. But the fate of whole societies depended on how they ground. Few things have had greater impact on the course of history.
Ken (his photo) tried soaking barley for a few days.
I have ground sprouted red wheat berries on my big Mexican matate – not the easiest – so I now resort to the food processor. Sprouted wheat with a two day tail makes a sweet sticky paste. I use it in my yeast bread but it also makes a great addition to flat breads and crackers. Yum!
Then Ken (his photo) pounded the barley in a large mortar for twenty minutes.
It was an odd red prairie barley I picked up at Corti Brothers in Sacramento, meant to be cooked like rice. So I have no idea how old, how far prepared or anything. They were not pearled like barley you buy for soup. More like a whole grain. And after pounding (just soaked, not cooked) it was a coarse dough. Which only really held together well after I added ground dry flour. SO maybe that’s why there’s not wet milling. You need dry flour too.
Ken didn’t photograph the final result but I suspect it was nothing like as finely divided as a ground grain dish would be. And the hull (the tight seed coat) is not going to be broken into fine particles by pounding. Shearing does a much better job than pounding at breaking up the seed coat and reducing the interior to tiny particles.
Here’s my tentative summary of the situation.
So Ken pounded not sheared in your mortar. That is quicker and easier than shearing because you can use the weight of arm plus pestle. But as the photo shows it does not produce flour just smashed… grains.
To get either smooth masa or a fine flour (not a very coarse meal) you have to shear. Shearing is almost impossible in a pestle and mortar if you want to produce flour in quantity because you are turning your wrist, tiring and not very forceful.
Maize nixtamalized can be ground to a smooth masa but only on a lateral grindstone, not a rotary one. You use the weight of the body.
Dry maize, wheat, barley etc can be ground to a smooth flour on a lateral (body weight at work, usually though not always) or a rotary grindstone (weight of the upper stone doing the work).
Wet wheat, barley etc (and I think wet, unnixtamalized maize) can be ground to a paste on a lateral grindstone but only with difficulty (thanks Leni).
Wet rice can be ground to a slurry (but not a paste) on a rotary grindstone (thanks Adam). Pastes gum up rotary grindstones (which is why in Mexico there were two kinds of grinding, water mills for wheat and lateral grindstones for wet maize).
Wet or dry grains can be broken or flaked by pounding with a pestle and mortar.
A couple more thoughts.
1. Flour is pretty perishable which is why grains were stored whole, not as flour. But wet pastes (masa) are much, much more perishable. They don’t keep from one day to the next. You have to have powerful reasons to want to grind wet.
2. Flour can be sifted through a cloth to remove all of part of the bran (the broken up seed coat). This can’t be done with a paste (the coat of maize is rubbed off before grinding wet, having been broken up by the alkali used in nixtamalization). Since people have always preferred finer, whiter breads, this was another advantage to flour.