I used to process acorns for years when I lived in California where they were super abundant and large. Usually I would clip each one in half and then be able to toss any that were wormy or spoiled. These were white oak group acorns, which are lower tannin and spoil quickly. Native people there preferred black oak acorns since they don't spoil as quickly (dropping in fall and germinating the following spring, white oaks often sprout right away) and can store longer in the shell. Usually an acorn will give a tell...a discoloration or a spot or a separation from the cap that indicates a worm or mold or something inside....some trial and error should demonstrate this and help your selection.
My default way to process them was to get them out of the shell and then dry the nuts rock hard in the sun, at which point one can winnow off the thin dark skin that may still be clinging to them, and then store them that way in jugs. Then when I wanted to make some up I would grind these pieces to flour in a heavy vitamix blender, and then leach them by leaving them in a colander lined with fabric under some dripping water....often outside near a thirsty plant. The acorns I had were done in a day of this, black oaks might take longer. Just taste it and when it's bland and not bitter or acrid it's done. At that point you can cook them any way you would cook corn grits or polenta, or else blend with some wheat or other flour for breads of various kinds. When I had a lot of them I would also crack them coarsely and leach for a few days, in multiple changes of standing water in buckets, and then feed them to my chickens.
